Upregulation of hsa_circ_0136666 contributes to breast cancer progression by sponging miR-1299 and targeting CDK6

Circular RNAs (circRNAs) can participate in multiple cancers, including breast cancer. Increasing circRNAs are recognized in various cancers because of the high-throughput sequencing. However, the potential physiological effect of hsa_circ_0136666 in breast cancer progression is unknown. In our study, the biological role of hsa_circ_0136666 in breast cancer development was studied. It was displayed that hsa_circ_0136666 was greatly increased in breast cancer. In addition, overexpression of hsa_circ_0136666 was able to promote Michigan Cancer Foundation-7 (MCF7) and BT474 cell proliferation and triggered cell cycle in G2/M phase. microRNA plays critical role in tumor development and they can act as direct targets of circRNAs. miR-1299 has been implicated as a famous tumor suppressor in many cancers. Here, miR-1299 was predicted as the target of hsa_circ_0136666. Meanwhile, its Upregulation repressed breast cancer proliferation, migration and invasion capacity, which could be reversed by the increase of hsa_circ_0136666. Furthermore, Cyclin-dependent kinase 6 (CDK6) was speculated as the downstream target of miR-1299. In MCF7 and BT474 cells, CDK6 was greatly overexpressed and it was shown that CDK6 contributed a lot to breast cancer progression. Subsequently, it was implied that hsa_circ_0136666 could modulate CDK6 levels positively in vitro. In conclusion, it was revealed that Upregulation of hsa_circ_0136666 promoted breast cancer progression by sponging miR-1299 and targeting CDK6.     

Hsa_circ_0136666 promotes the proliferation and invasion of colorectal cancer through miR-136/SH2B1 axis

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. Currently, an increasing evidence showed that circular RNAs (circRNAs) play important roles in tumor progression. However, the effects and underlying mechanisms of circRNAs in CRC progression remain unclear. In the present study, through circRNA high-throughput sequencing and quantitative real-time polymerase chain reaction, we identified that hsa_circ_0136666 was significantly overexpressed in CRC tissues and cell lines. High hsa_circ_0136666 expression was associated with poor overall survival of patients with CRC. In vitro function assays showed that hsa_circ_0136666 inhibition suppressed CRC cell proliferation, migration, invasion, and arrested CRC cells in the G0/G1 phase. Furthermore, we showed that hsa_circ_0136666 inhibition reduced CRC cell growth in vivo. Mechanistically, we revealed that hsa_circ_0136666 could increase SH2B1 expression via competitively binding miR-136 in CRC cells. In addition, SH2B1 overexpression could reverse the effects of hsa_circ_0136666 inhibition on CRC cell progression. In conclusion, our data suggested that hsa_circ_0136666 could promote CRC cell progression via the miR-136/SH2B1 axis, elucidating a novel approach to improve the effectiveness of CRC treatment.     

Circular RNA hsa_circ_0011385 contributes to cervical cancer progression through sequestering miR-149–5p and increasing PRDX6 expression

Cervical cancer (CC) is a common tumor in the female reproductive tract. Circular RNA hsa_circ_0011385 has been reported to be up-regulated in CC tissues. Nevertheless, the role and regulatory mechanism of hsa_circ_0011385 in CC are still being further verified. The levels of hsa_circ_0011385, microRNA (miR)? 149–5p, and peroxiredoxin 6 (PRDX6) mRNA in CC samples and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Loss-of-function experiments were performed to survey the impacts of hsa_circ_0011385 inhibition on CC cell proliferation, colony formation, cycle progression, apoptosis, metastasis, invasion, and angiogenesis. Protein levels were detected by western blotting. The relationship between hsa_circ_0011385 or PRDX6 and miR-149–5p was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP), and/or RNA pull-down assays. The tumorigenesis role of hsa_circ_0011385 in CC was confirmed by xenograft assay. We observed that hsa_circ_0011385 and PRDX6 were up-regulated while miR-149–5p was down-regulated in CC samples and cell lines. CC patients with high hsa_circ_0011385 expression possessed a shorter overall survival. Hsa_circ_0011385 knockdown reduced tumor growth in vivo and facilitated apoptosis, cell cycle arrest, impeded proliferation, metastasis, invasion, and angiogenesis of CC cells in vitro. Hsa_circ_0011385 could mediate PRDX6 expression through binding to miR-149–5p. MiR-149–5p silencing reversed hsa_circ_0011385 knockdown-mediated effects on CC cell angiogenesis and malignancy. PRDX6 overexpression overturned the inhibitory effects of miR-149–5p overexpression on angiogenesis and malignant behaviors of CC cells. In conclusion, hsa_circ_0011385 accelerated angiogenesis and malignant behaviors of CC cells by regulating the miR-149–5p/PRDX6 axis, manifesting that hsa_circ_0011385 might be a therapeutic target for CC.     

Hsa_circ_0069094 positively regulates the expression of oncogenic ZNF217 by competitively targeting miR-758–3p to promote the development of breast cancer

To investigate the functions and potential mechanisms of hsa_circ_0069094 in this cancer. The expression of hsa_circ_0069094, zinc finger protein 217 (ZNF217) and microRNA-758–3p (miR-758–3p) was detected by quantitative polymerase chain reaction (qPCR), and the protein level of ZNF217 was detected by western blot. Cell proliferation was assessed using cell counting kit-8 (CCK-8) assay and colony formation assay. Cell cycle progression and cell apoptosis were determined using flow cytometry assay. Cell invasion and cell migration were monitored using transwell assay and wound healing assay. The protein levels of apoptosis-related proteins were quantified by western blot. The putative relationship between miR-758–3p and hsa_circ_0069094 and ZNF217 was confirmed using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Xenograft model was constructed in mice to explore the role of hsa_circ_0069094 on solid tumor growth.Hsa_circ_0069094 and ZNF217 were highly expressed, while miR-758–3p was poorly expressed in tissues and cells of breast cancer. Hsa_circ_0069094 knockdown or ZNF217 knockdown inhibited cell proliferation, invasion and migration and induced cell apoptosis and cell cycle arrest in breast cancer cells. The inhibitory effects of hsa_circ_0069094 knockdown on cell malignant behaviors were abolished by ZNF217 overexpression. Hsa_circ_0069094 competed with ZNF217 for the binding site of miR-758–3p, and hsa_circ_0069094 positively regulated ZNF217 expression by competitively binding to miR-758–3p. Hsa_circ_0069094 knockdown also blocked solid tumor growth in mice. Collectively, Hsa_circ_0069094 played oncogenic effects in breast cancer by activating the expression of ZNF217 via competitively binding to miR-758–3p, which might be a novel strategy for breast cancer suppression.     

Knockdown of LncRNA PVT1 inhibits tumorigenesis in non-small-cell lung cancer by regulating miR-497 expression

Plasmacytoma variant translocation1 (PVT1) was reported to be upregulated in non-small-cell lung cancer (NSCLC) tissues, serve as a promising biomarker for diagnosis and prognosis of NSCLC, and promoted NSCLC cell proliferation. However, the detailed molecular mechanism of PVT1 involved in the pathogenesis and development of NSCLC remains largely unknown. In this study, the expression levels of PVT1 and miR-497 in NSCLC cells were determined by qRT-PCR. Cell viability, invasion and apoptosis were detected by MTT assay, cell invasion assay and flow cytometry analysis, respectively. RNA immunoprecipitation (RIP) and luciferase reporter assay were performed to confirm whether PVT1 directly interacts with miR-497. A xenograft mouse model was established to confirm the effect of PVT1 on tumor growth in vivo and the underlying molecular mechanism. Our findings indicated that PVT1 was significantly upregulated and miR-497 was markedly downregulated in NSCLC cell lines. si-PVT1 effectively decreased the expression of PVT1 and increased the expression of miR-497. PVT1 knockdown remarkably inhibited cell viability, invasion and promoted apoptosis in NSCLC cells. RIP and luciferase reporter assay demonstrated that PVT1 could directly interact with miR-497. Moreover, PVT1 overexpression reversed the inhibitory effect of miR-497 on cell viability, invasion and promotion effect on apoptosis of NSCLC cells. Furthermore, in vivo experiment showed that knockdown of PVT1 inhibited tumor growth in vivo and promoted miR-497 expression. In conclusion, knockdown of PVT1 inhibited cell viability, invasion and induced apoptosis in NSCLC by regulating miR-497 expression, elucidating the molecular mechanism of the oncogenic role of PVT1 in NSCLC and providing an lncRNA-directed target for NSCLC.     

Circular RNA hsa_circ_0000263 participates in cervical cancer development by regulating target gene of miR-150-5p

Circular RNA (circRNA) is a new class of noncoding RNA, and plays an important role in many pathological processes. Cervical cancer is the most common gynecologic malignant tumor. Recently, studies have shown that there is a variety of circRNA involved in the pathogenesis of cervical cancer. We screened out the highly expressed hsa_circ_0000263 from GSE102686 by the quantitative real-time polymerase chain reaction assay in cervical cancer cell lines. In this study, we investigated whether hsa_circ_0000263 might affect cell proliferation, migration, cell cycle and apoptosis in cervical cancer in vitro and in vivo. The luciferase reporter assay and RNA immunoprecipitation assay confirmed the direct interaction between miR-150-5p and hsa_circ_0000263. By using western blot and immunohistochemistry, we confirmed that hsa_circ_0000263 can regulate the expression of murine double minute 4 (MDM4) by affecting miR-150-5p, and finally affect the expression of p53 gene. We found that hsa_circ_0000263 was significantly upregulated in cervical cancer cells. In addition, the knockdown of hsa_circ_0000263, would inhibit cell proliferation and migration ability. In conclusion, our current research reveals the important role of hsa_circ_0000263/miR-150-5p/MDM4/p53 regulatory network in cervical cancer and provides a new insight into the pathogenesis of cervical cancer.     

hsa_circ_0003222 accelerates stemness and progression of non-small cell lung cancer by sponging miR-527

The relationship between circular RNA (circRNA) and cancer stem cells (CSCs) is uncertain. We have investigated the combined influence of CSCs, circRNA (hsa_circ_0003222), and immune checkpoint inhibitors in NSCLC progression and therapy resistance. We constructed lung CSCs (LCSCs; PC9 and A549). The effects of hsa_circ_0003222 in vitro were determined by cell counting, colony and sphere formation, and Transwell assays. A tumor xenograft model of metastasis and orthotopic model were built for in vivo analysis. We found that hsa_circ_0003222 was highly expressed in NSCLC tissues and LCSCs. Higher levels of hsa_circ_0003222 were associated with the stage, metastasis, and survival rate of patients with NSCLC. Reduced levels of hsa_circ_0003222 decreased tumor cell proliferation, migration, invasion, stemness-like properties, and chemoresistance. The silencing of hsa_circ_0003222 was found to downregulate PHF21B expression and its downstream, β-catenin by relieving the sponging effect of miR-527. Moreover, silencing hsa_circ_0003222 alleviated NSCLC resistance to anti-programmed cell death-ligand 1 (PD-L1)-based therapy in vivo. Our data demonstrate the significant role of hsa_circ_0003222 in NSCLC cell stemness-like properties. The manipulation of circRNAs in combination with anti-PD-L1 therapy may alleviate NSCLC stemness and progression.Subject terms: Cancer microenvironment, Cancer stem cells     

Hsa_circ_0000119 promoted ovarian cancer development via enhancing the methylation of CDH13 by sponging miR-142-5p

Ovarian cancer is the leading cause of gynecological cancer-related death in women, and is difficult to treat. The aim of our study is to explore the role and action mechanism of hsa_circ_0000119 in ovarian cancer, thus to analyze whether the circular RNA is a potential target for the treatment of the disease. In this present study, our data shows that hsa_circ_0000119 and DNA methyltransferase 1 (DNMT1) was increased, while miR-142-5p was decreased in ovarian cancer. Overexpression of hsa_circ_0000119 promoted tumor growth, while silencing of hsa_circ_0000119 resulted in an opposite effects. Decreasing of hsa_circ_0000119 also notably inhibited the proliferation, migration, and invasion of the ovarian cancer cells. Moreover, the data proves that hsa_circ_0000119 negatively regulated miR-142-5p and cadherin 13 (CDH13) expression, but positively regulated DNMT1 expression. miR-142-5p could interact with hsa_circ_0000119 and DNMT1 3′-UTR. Silencing of DNMT1 could reverse the inhibition of hsa_circ_0000119 to miR-142-5p and CDH13 expression. Importantly, higher level of CDH13 promoter methylation existed in the ovarian tumors than that in matched normal tissues. DNA methyltransferase inhibitor could increase the expression of CDH13 in ovarian cancer cells. In addition, our results also prove that increasing of CDH13 or miR-142-5p effectively reversed the inhibition of hsa _circ_0000119 to the cell malignant phenotypes. Overall, our data demonstrate that hsa_circ_0000119 facilitated ovarian cancer development through increasing CDH13 expression via promoting DNMT1 expression by sponging miR-142-5p. Our data demonstrate the potential role of hsa_circ_0000119 in the treatment of ovarian cancer.     

Hsa_circ_0001495 contributes to cervical cancer progression by targeting miR-526b-3p/TMBIM6/mTOR axis

Cervical cancer (CC) is a common gynecological malignant tumor, causing poor survival rate. Circular RNAs (circRNAs) are abundantly expressed in CC with their stable loop structure. However, the underlying mechanism and biological function of circRNAs remained unclear. Using quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay, we measured the expression of hsa_circ_0001495, miR-526b-3p, and transmembrane Bax inhibitor motif containing 6 (TMBIM6) in CC tissues and cells. The relationship between miR-526b-3p and hsa_circ_0001495 or TMBIM6 was investigated by bioinformatics analysis, dual-luciferase and RIP analysis. Enzyme linked immunosorbent assay (ELISA) was conducted to evaluate glucose consumption and lactate production. 5-ethynyl-2′-deoxyuridine (EDU) assay were used to test cell proliferation. Cell apoptosis was analyzed by using flow cytometry assay. Transwell and wound-healing assays were used to measure cell invasion and migration. The expression of proteins was examined by western blot. Xenograft assay was applied to detect the effect of hsa_circ_0001495 in vivo. Our finding showed that hsa_circ_0001495 and TMBIM6 expression were upregulated, while miR-526b-3p was downregulated in CC tissues and cell lines. Hsa_circ_0001495 knockdown or TMBIM6 knockdown suppressed cell proliferation, migration, glycolysis, while promoted cell apoptosis in vitro, and hsa_circ_0001495 silence curbed tumor growth in vivo. Beside, hsa_circ_0001495 exerted its function in CC by positively regulating TMBIM6. Furthermore, hsa_circ_0001495 acted as a sponge for miR-526b-3p to regulate TMBIM6 expression. Hsa_circ_0001495/miR-526b-3p/TMBIM6 axis also regulated the phosphorylation of mammalian target of rapamycin (mTOR) in CC cells. In summary, hsa_circ_0001495 regulated the progression of CC by regulating miR-526b-3p/TMBIM6/mTOR pathway.     

Hsa_circ_0003596 enhances the development of cell renal clear cell carcinoma through the miR-502-5p/IGF1/PI3K/AKT axis

Accumulating research findings have shown that circular RNAs (circRNAs) play an indispensable role in tumorigenesis and tumor progression. The current study aimed to explore the role and modulatory mechanism of hsa_circ_0003596 in clear cell renal cell carcinoma (ccRCC). Quantitative real-time polymerase chain reaction was adopted to detect the expression of hsa_circ_0003596 in ccRCC tissue and cell lines. 5-Ethynyl-2′-deoxyuridine, cell counting kit 8 and the colony formation assay were utilized to assess the proliferation potential of the ccRCC cells. Transwell along with wound healing assays were adopted to quantify infiltration coupled with the migration potential of the cells. The current research study found that the circRNA hsa_circ_0003596 was overexpressed in ccRCC tissue and cell lines. Further, result showed that hsa_circ_0003596 was associated with distant metastasis of renal cancer. Notably, the knockdown of hsa_circ_0003596 can lower the proliferation, infiltration and migration potential of ccRCC cells. The results of in vivo experiments found that the reduction of hsa_circ_0003596 significantly hampered the growth of tumors in mice. In addition, it was evident that hsa_circ_0003596 acts as a “molecular sponge” for miR-502-5p to upregulate the expression of the microRNA-502-5p (miR-502-5p) target insulin-like growth factor 1 (IGF1R). Furthermore, it was found that the phosphatidylinositol 3-kinase (PI3K)/AKT signaling was the downstream cascade of hsa_circ_0003596/miR-502-5p/IGF1R cascade, which is partly responsible for the cancer-promoting effect. Overall, the results of the present study showed that hsa_circ_0003596 facilitated the proliferation, infiltration and migration of ccRCC through the miR-502-5p/IGF1R/PI3K/AKT axis. Therefore, it was evident that hsa_circ_0003596 can serve as a possible biomarker and therapeutic target against ccRCC.     

Hsa_circ_0128846 promotes tumorigenesis of colorectal cancer by sponging hsa‐miR‐1184 and releasing AJUBA and inactivating Hippo/YAP signalling

Hsa_circ_0128846 was found to be the most significantly up‐regulated circRNA in our bioinformatics analysis. However, the role of hsa_circ_0128846 in colorectal cancer has not been explored. We thus aim to explore the influence and mechanism of hsa_circ_0128846 in colorectal cancer by sponging its downstream miRNA target miR‐1184. We collected 40 colorectal cancer patients’ tumour tissues to analyse the expression of hsa_circ_0128846, miR‐1184 and AJUBA using qRT‐PCR and Western blot where needed. Then, we constructed stably transfected SW480 and HCT116 cells to study the influence of hsa_circ_0128846, miR‐1184 and AJUBA on colorectal cancer cell phenotypes. To obtain reliable results, a plethora of experiments including RNA immunoprecipitation assay, flow cytometry, EdU incorporation assay, wound healing migration assay, transwell invasion assay and live imaging of nude mice xenograft assay were performed. The binding relationship between hsa_circ_0128846, miR‐1184 and AJUBA mRNA in colorectal cancer was validated by reported gene assay. In colorectal cancer tissues, circ_0128846 and AJUBA were both significantly up‐regulated, while miR‐1184 was significantly down‐regulated compared with healthy tissues. Meanwhile, hsa_circ_0128846 can absorb miR‐1184 to promote the progression of CRC in vivo and SW480 and HCT116 cell phenotypes in vitro. The knockdown of AJUBA, a downstream target of miR‐1184, reversed the effect of miR‐1184 in CRC cells via enhancing the phosphorylation of the Hippo/YAP signalling pathway proteins MST1, LATS1 and YAP. This study revealed that hsa_circ_0128846 contributed to the development of CRC by decreasing the expression of miR‐1184, thereby increasing AJUBA expression and inactivating Hippo/YAP signalling.     

miR-155-TP53INP1调节轴在结直肠癌化疗药物敏感性中的作用机制

摘要 目的：初步揭示miR-155通过靶向调节TP53INP1表达水平影响结直肠癌细胞对5-FU化疗敏感性。方法：将人结肠直肠癌细胞系HCT116进行培养,提取细胞总RNA后,采用miR-155逆转录特异性引物构建反转录体系进行PCR扩增,通过qRT-PCR检测miR-155在5-FU耐药细胞HCT116/FU及敏感细胞株HCT116中的表达情况;取对数生长期细胞,分别转染miR-155mimics、miR-155抑制剂、miR-155阴性对照后,采用CCK-8法检测miR-155对细胞5-FU药物敏感性的影响,双荧光素酶报告基因系统验证miR-155与TP53INP1的靶基因关系,Western blot检测miR-155对 TP53INP1表达的影响。结果：miR-155在HCT116 /Fu细胞中的表达量是HCT116细胞的7.25倍;在相同5-FU浓度时,HCT116+阴性对照的细胞生长抑制率均高于HCT116+mimics、半数抑制浓度显著低于HCT116+mimics,差异均具有统计学意义(P＜0.05);TP53INP1是miR-155的靶基因,能显著降低野生型TP53INP1 3''-UTR的荧光素酶活性;转染miR-155 mimics后,TP53INP1的相对表达量显著下降,转染miR-155抑制剂后,TP53INP1的相对表达量显著升高,差异均具有统计学意义(P＜0.05)。结论：miR-155水平升高使HCT116细胞对5-FU的敏感性降低,miR-155可能通过靶向调节TP53INP1的表达水平,从而影响结直肠癌细胞对5-FU的敏感性。     

Exosomal transfer of tumor-associated macrophage-derived hsa_circ_0001610 reduces radiosensitivity in endometrial cancer

The occurrence of radioresistance is a clinical obstacle to endometrial cancer (EC) treatment and induces tumor relapse. In this study, we found that tumor-associated macrophages (TAMs) enriched in EC specimens were determined to present an M2-like phenotype. In vitro, the coculture of M2-polarized macrophages significantly downregulated the radiosensitivity of EC cells by releasing exosomes. Hsa_circ_0001610 was found to be abundant in exosomes derived from M2-polarized macrophages (EXOs), and hsa_circ_0001610 knockdown eliminated the reduction effect of EXOs on the radiosensitivity of EC cells. The following mechanism research revealed that hsa_circ_0001610 functioned as the competing endogenous RNA of miR-139-5p, thereby upregulating cyclin B1 expression, which is a vital pusher of radioresistance in several types of cancer by regulating the cell cycle. Hsa_circ_0001610 overexpression reduced the radiosensitivity of EC cells, which was then reversed by miR-139-5p overexpression. In vivo, the promotion effect of EXOs on xenograft tumor growth in nude mice treated with irradiation was further reinforced after hsa_circ_0001610 overexpression. In conclusion, TAM-derived exosomes transferred hsa_circ_0001610 to EC cells, and the overexpressed hsa_circ_0001610 in EC cells released cyclin B1 expression through adsorbing miR-139-5p, thereby weakening the radiosensitivity of EC cells.Subject terms: Cancer, Cell biology     

LncRNA HAND2-AS1 inhibits 5-fluorouracil resistance by modulating miR-20a/PDCD4 axis in colorectal cancer

BackgroundChemoresistance is one of the main obstacles in the therapy of human cancers, including colorectal cancer (CRC). Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (lncRNA HAND2-AS1) has been demonstrated to be associated with CRC. However, the function of HAND2-AS1 in 5-Fluorouracil (5-FU) resistance of CRC remains unclear.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression of HAND2-AS1, miR-20a and programmed cell death factor 4 (PDCD4) mRNA. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was conducted to evaluate IC50 of 5-FU and cell proliferation. Flow cytometry analysis was used to determine cell apoptosis. Transwell assay was carried out to measure cell migration and invasion. Western blot assay was conducted to examine the protein levels of B-cell lymphoma-2 (Bcl-2), BCL2-Associated X (Bax), matrix metalloprotein 2 (MMP2), MMP9 and PDCD4. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull down assay were utilized to verify the combination between miR-20a and HAND2-AS1. Dual-luciferase reporter assay was used to analyze the association between miR-20a and PDCD4. Murine xenograft assay was used to confirm the function of HAND2-AS1 in vivo.ResultsHAND2-AS1 and PDCD4 were downregulated and miR-20a was upregulated in 5-FU-resistant CRC tissues and cells. HAND2-AS1 suppressed 5-FU resistance, cell proliferation, migration and invasion and promoted cell apoptosis in 5-FU-resistant CRC cells. HAND2-AS1 acted as a sponge of miR-20a to regulate PDCD4 expression. Moreover, HAND2-AS1 suppressed cell progression and 5-FU resistance by upregulating PDCD4 via sponging miR-20a in 5-FU-resistant CRC cells. Besides, HAND2-AS1 inhibited tumor growth in vivo.ConclusionHAND2-AS1/miR-20a/PDCD4 axis inhibited cell progression and 5-FU resistance in 5-FU-resistant CRC cells.     

The effect of Curcumin on multi-level immune checkpoint blockade and T cell dysfunction in head and neck cancer

BackgroundDespite recent advances in understanding the complex immunologic dysfunction in the tumor microenvironment (TME), fewer than 20% of patients with head and neck squamous cell carcinoma (HNSCC) respond to immune checkpoint blockade (ICB). Thus, it is important to understand how inhibitory IC receptors maintain the suppressed dysfunctional TME, and to develop more effective combination immunotherapy. This study evaluated the immune-modulating effects of Curcumin, which has well-established anti-cancer and chemopreventive properties, and its long-term safety as a phytochemical drug.MethodsWe carried out the western blot and small interfering RNA (siRNA) transfection assay to evaluate the effects of Curcumin on IC ligands and IC ligands function in HNSCC. Through T-cell cytotoxicity assay and measurements of cytokine secretion, we assessed the effects of combination of Curcumin with programmed death-ligand 1 (PD-L1) Ab on cancer cell killing. Flow cytometry were used to analyze the effects of Curcumin on the expression of programmed cell death protein 1 (PD-1) and T-cell immunoglobulin and mucin-domain3 (TIM-3) on CD4, CD8 and Treg. Immunofluorescence, immunohistochemistry and western blot were used to detecte the cytokine (IFN-γ, Granzyme B), IC receptors (PD-1 and TIM-3) and its ligands (PD-L1, PD-L2, Galectin-9) in xenograft mouse model and 4-nitroquinoline-1-oxide (4-NQO) oral cancer model.ResultsWe found that Curcumin decreased the expression of IC ligands such as PD-L1, PD-L2, and Galectin-9 in HNSCC, leading to regulation of epithelial-to-mesenchymal transition-associated tumor invasion. Curcumin also effectively restored the ability of CD8⁺ cytotoxic T cells to lyse cancer cells. To evaluate the effect of Curcumin on the TME further, the 4-NQO oral cancer model was used. Curcumin increased T-cell proliferation, tumor-infiltrating lymphocytes (TILs), and effector cytokines, and decreased the expression of PD-1, TIM-3, suppressive IC receptors and their ligands (PD-L1, PD-L2, and Galectin-9) in the TME, implying reinvigoration of the exhausted CD8⁺ T cells. In addition, Curcumin inhibited expression of CD4⁺CD25⁺FoxP3⁺ Treg cells as well as PD-1 and TIM-3.ConclusionsThese results show that Curcumin reinvigorates defective T cells via multiple (PD-1 and TIM-3) and multi-level (IC receptors and its ligands) IC axis suppression, thus providing a rationale to combine Curcumin with conventional targeted therapy or ICB as a multi-faceted approach for treating patients with HNSCC.     

CircRNA VIM silence synergizes with sevoflurane to inhibit immune escape and multiple oncogenic activities of esophageal cancer by simultaneously regulating miR-124/PD-L1 axis

Background

Circular RNA of vimentin (circ-VIM) is a predictor for poor prognosis of acute myeloid leukemia, but we had little information on its function in esophageal cancer (EC). Here we examined the effects of circ-VIM together with sevoflurane on immune escape and multiple oncogenic activities of EC.

Methods

Bioinformatic tools, luciferase assay, and RNA immunoprecipitation were used to examine regulations between circ-VIM, miR-124-3p (miR-124), and PD-L1. CCK-8, wound healing, and Transwell assays were used to measure cell proliferation, migration, and invasion, respectively. The impacts of EC cells on cytotoxicity, proliferation, and apoptosis of CD8⁺ T cells were examined using LDH assay, CFSE staining, and Annexin V/PI staining, respectively. The in vivo tumorigenesis and lung metastases were assessed using xenograft model and tail vein injection of EC cells.

Results

Significant upregulation of circ-VIM and PD-L1 and downregulation of miR-124 were detected in EC tissues or cells. Circ-VIM sponged miR-124 and released its suppression on the downstream target PD-L1. Sevoflurane, independent of circ-VIM, also upregulated miR-124 to lower PD-L1 expression. By modulating miR-124/PD-L1 axis, silencing circ-VIM and applying sevoflurane both inhibited immune escape and multiple oncogenic activities of EC in vitro, and suppressed xenograft growth and lung metastases in vivo. The inactivation of Ras/ERK signaling pathway was involved in suppression of malignant phenotypes by silencing circ-VIM and sevoflurane treatment.

Conclusions

Silencing circ-VIM and applying sevoflurane, by separately regulating miR-124/PD-L1 axis, presented synergistic effects in inhibiting immune escape and multiple malignant phenotypes of EC cells.

Graphical abstract

     

Hsa_circ_0092276 promotes doxorubicin resistance in breast cancer cells by regulating autophagy via miR-348/ATG7 axis

Previous study has confirmed that hsa_circ_0092276 is highly expressed in doxorubicin (DOX)-resistant breast cancer cells, indicating that hsa_circ_0092276 may be involved in regulating the chemotherapy resistance of breast cancer. Here we attempted to investigate the biological role of hsa_circ_0092276 in breast cancer. We first constructed DOX-resistant breast cancer cells (MCF-7/DOX and MDA-MB-468/DOX). The 50% inhibiting concentration of MCF-7/DOX and MDA-MB-468/DOX cells was significantly higher than that of their parental breast cancer cells, MCF-7 and MDA-MB-46. MCF-7/DOX and MDA-MB-468/DOX cells also exhibited an up-regulation of drug resistance-related protein MDR1. Compared with MCF-7 and MDA-MB-46 cells, hsa_circ_0092276 was highly expressed in MCF-7/DOX and MDA-MB-468/DOX cells. Hsa_circ_0092276 overexpression enhanced proliferation and the expression of LC3-II/LC3-I and Beclin-1, and repressed apoptosis of breast cancer cells. The effect of hsa_circ_0092276 up-regulation on breast cancer cells was abolished by 3-methyladenine (autophagy inhibitor). Hsa_circ_0092276 modulated autophagy-related gene 7 (ATG7) expression via sponging miR-384. Hsa_circ_0092276 up-regulation promoted autophagy and proliferation, and repressed apoptosis of breast cancer cells, which was abolished by miR-384 overexpression or ATG7 knockdown. In addition, LV-circ_0092276 transfected MCF-7 cell transplantation promoted autophagy and tumor growth of breast cancer in mice. In conclusion, our data demonstrate that hsa_circ_0092276 promotes autophagy and DOX resistance in breast cancer by regulating miR-348/ATG7 axis. Thus, this article highlights a novel competing endogenous RNA circuitry involved in DOX resistance in breast cancer.     

Downregulation of hsa_circ_0001681 suppresses epithelial-mesenchymal transition in thyroid carcinoma via targeting to miR-942-5p/TWIST1 signaling pathway

Thyroid carcinoma (TC) seriously threatens the health and safety of patients, and the treatment target of it still is poor. RT-qPCR and Western blot were carried out to detect the expression of genes and proteins, respectively. Cell proliferation was confirmed using colony formation assay. Transwell assay were performed to measure the cell migration and invasion. Besides, luciferase reporter assay was accomplished to ensure the target relationship between miR-942-5p and TWIST1 mRNA as well as hsa_circ_0001681. Here, we proved that hsa_circ_0001681 was increased in TC, and located majorly in the cytoplasm of TC cells. However,  miR-942-5p was decreased in TC, and was negatively correlated with hsa_circ_0001681 expression. Knockdown of hsa_circ_0001681 significantly repressed the proliferation, migration, invasion and EMT of TC cells. We also found that the process of hsa_circ_0001681 silencing limited EMT, which was obstructed by TWIST1 increasing. Moreover, hsa_circ_0001681 acted as a miRNA sponge and completed with TWIST1 mRNA for binding to miR-942-5p, thus downregulation of hsa_circ_0001681 repressed EMT and subsequent malignant phenotype of TC cells through targeting miR-942-5p/TWIST1 signaling pathway. Finally, the studies in vivo showed that decreasing of hsa_circ_0001681 effectively inhibited the growth of tumor via repressing EMT by regulating miR-942-5p/TWIST1 signaling pathway. Overall, silencing of hsa_circ_0001681 significantly suppressed TC progression through inhibiting EMT via acting as a miR-942-5p sponge to facilitate the expression of TWIST1. Our data provided a reliable evidence for hsa_circ_0001681 is a potential treatment target in TC.

     

lncRNA XIST-miR137-ATG5调节细胞自噬功能在肠癌细胞5-氟胞嘧啶耐药性中的作用

摘要 目的：本文旨在研究长链非编码RNA XIST-miR137-ATG5的相互作用,同时探讨其调节细胞自噬功能与肠癌细胞5-氟胞嘧啶敏感性的关系。方法：实时聚合酶链反应(real time PCR)检测XIST与miR-137在肠癌细胞中的表达;采用脂质体转染法将si-XIST,miR-137转染入肠癌SW480及HCT116细胞中。采用CCK-8检测瞬时转染si-XIST对肠癌细胞增殖及5-FU敏感性的影响;并利用双荧光素酶报告实验检测miR-137与XIST, miR-137与ATG5相互关系。Western blot方法检测XIST- miR137- ATG5对细胞自噬的影响。结果：与正常结肠细胞FHC比较, XIST在结肠癌细胞系明显高表达,miR-137在结肠癌细胞系明显低表达。与阴性对照组比较,转染si-XIST后,SW480及HCT116细胞增殖能力明显受到抑制,对F-5U的敏感性增强,且抑制自噬蛋白Beclin-1及LC3II/LC3 I的表达。miR-137可与XIST,ATG5 3''UTR结合,抑制XIST和ATG5的表达及功能。在结肠癌SW480细胞中共转染miR-137 inhibitor或过表达ATG5可逆转XIST沉默引起的5-FU耐药,同时可逆转因XIST沉默引起的自噬蛋白表达的抑制。结论：LncRNA XIST或可通过调控mir137-ATG促进结直肠癌细胞SW480自噬从而提高其对5-FU的耐药,针对其这一机制,可为将来针对结肠癌的靶向治疗提供一定的实验基础。