Suppression of bcl-2 gene by RNA interference increases chemosensitivity to cisplatin in nasopharyngeal carcinoma cell line CNE1

To explore the effect of suppressing BCL-2 expression using RNA interference (RNAi) technique in nasopharyngeal carcinoma cell line CNE1. CNE1 cell lines stably expressing shRNAs targeted bcl-2 and GL3 gene were established and gene expression inhibition was assessed by Western blotting analysis. The effect of suppressing bcl-2 by RNAi on cell growth was studied, the apoptosis induction and the sensitization of CNE1 cells to cisplatin were quantified by MTT assay and flow cytometry. The results showed that: stable transfection of CNE1     

The deacetylation of Foxk2 by Sirt1 reduces chemosensitivity to cisplatin

In multiple types of cancer, decreased tumour cell apoptosis during chemotherapy is indicative of decreased chemosensitivity. Forkhead box K2 (FOXK2), which is essential for cell fate, regulates cancer cell apoptosis through several post‐translational modifications. However, FOXK2 acetylation has not been extensively studied. Here, we evaluated the effects of sirtiun 1 (SIRT1) on FOXK2 deacetylation. Our findings demonstrated that SIRT1 inhibition increased FOXK2‐induced chemosensitivity to cisplatin and that K223 in FOXK2 was acetylated. Furthermore, FOXK2 K223 deacetylation reduced chemosensitivity to cisplatin in vitro and in vivo. Mechanistically, FOXK2 was acetylated by the acetyltransferase cAMP response element binding protein and deacetylated by SIRT1. Furthermore, cisplatin attenuated the interaction between FOXK2 and SIRT1. Cisplatin or SIRT1 inhibition enhanced FOXK2 acetylation, thereby reducing the nuclear distribution of FOXK2. Additionally, FOXK2 K223 acetylation significantly affected the expression of cell cycle–related and apoptosis‐related genes in cisplatin‐stimulated cancer cells, and FOXK2 K223 hyperacetylation promoted mitotic catastrophe, which enhanced chemosensitivity to cisplatin. Overall, our results provided insights into the mechanisms of SIRT1‐mediated FOXK2 deacetylation, which was involved in chemosensitivity to cisplatin.     

Testis developmental related gene 1 regulates the chemosensitivity of seminoma TCam‐2 cells to cisplatin via autophagy

We previously identified testis developmental related gene 1 (TDRG1), a gene implicated in proliferation of TCam‐2 seminoma cells. Recent evidence has revealed that autophagy influences the chemosensitivity of cancer cells to chemotherapy. However, whether TDRG1 protein regulates autophagy in seminoma cells and influences their sensitivity to cis‐dichlorodiammine platinum (CDDP) remains unknown. In this study, we used TCam‐2 cells and male athymic BALB/c nude mice with xenografts of TCam‐2 cells to investigate autophagy, cell viability, apoptosis and the p110β/Rab5/Vps34 (PI3‐kinase Class III) pathway under the conditions of TDRG1 overexpression or knockdown and with or without CDDP treatment. We found that TDRG1 upregulation promoted autophagy in both TCam‐2 cells and seminoma xenografts via p110β/Rab5/Vps34 activation. Inhibition of autophagy reduced cell viability and promoted apoptosis during CDDP treatment of TCam‐2 cells. Similarly, TDRG1 knockdown inhibited autophagy, reduced cell viability and promoted apoptosis during CDDP treatment of TCam‐2 cells. TDRG1 knockdown inhibited tumour growth and promoted apoptosis in TCam‐2 cell xenografts, whereas TDRG1 overexpression had the opposite effect. According to these results, we propose that high expression of TDRG1 promotes autophagy through the p110β/Rab5/Vps34 pathway in TCam‐2 cells. TDRG1 overexpression promotes autophagy and leads to CDDP resistance, whereas TDRG1 knockdown inhibits autophagy and promotes chemosensitivity to CDDP both in vivo and in vitro. This study has uncovered a novel role of TDRG1 in reducing chemoresistance during CDDP treatment and provides potential therapeutic strategies for the treatment of human seminoma.     

AKR1C2 acts as a targetable oncogene in esophageal squamous cell carcinoma via activating PI3K/AKT signaling pathway

The aldo‐keto reductases family 1 member C2 (AKR1C2) has critical roles in the tumorigenesis and progression of malignant tumours. However, it was also discovered to have ambiguous functions in multiple cancers and till present, its clinical significance and molecular mechanism in oesophageal squamous cell carcinoma (ESCC) has been unclear. The aim of this study was to explore the role of AKR1C2 in the tumorigenesis of ESCC. Here, we showed that AKR1C2 expression was found to be up‐regulated in ESCC tissues and was significantly associated with pathological stage, lymph node metastasis and worse outcomes. Functional assays demonstrated that an ectopic expression of AKR1C2 in ESCC cells resulted in increased proliferation, migration and cisplatin resistance, while knockdown led to inversing effects. Bioinformation analyses and mechanistic studies demonstrated that AKR1C2 activated the PI3K/AKT signalling pathway, furthermore, the inhibitor of PI3K or the selective inhibitor of AKR1C2 enzyme activity could reverse the aggressiveness and showed synergistic antitumour effect when combined with cisplatin, both in vitro and in vivo. In conclusion, Our findings revealed that AKR1C2 could function as an oncogene by activating the PI3K/AKT pathway, as a novel prognostic biomarker and/or as a potential therapeutic target to ESCC.     

Hippo pathway contributes to cisplatin resistant-induced EMT in nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a kind of head-neck malignant tumor derived from the nasopharyngeal epithelium and is mainly prevalent in Southern China and Southeast Asia countries. Cisplatin (DDP) provides the first-line therapeutic administration in NPC patients. However, chemoresistance has been a main barrier and caused bad treatment outcome in NPC therapy. To understand the molecular mechanism of acquired resistance to DDP, multiple methods were performed to examine the morphocytology and molecular changes in DDP-resistant NPC cells. We found that drug resistance cells displayed epithelial-mesenchymal transition (EMT) characteristics. DDP-resistant NPC cells exhibited enhanced migration and invasion potential. Moreover, overexpression of TAZ, one key gene in Hippo pathway, is closely associated with the DDP resistance of NPC cells and its EMT properties. Depletion of TAZ in DDP-resistant cells reversed EMT phenotypes to MET characteristics and restored chemosensitivity of DDP-resistant cells to DDP treatment. These results suggest that inactivation of TAZ could be a promising approach for the treatment of NPC patients.     

AKR1B10与GPC-3免疫组化检测对肝细胞肝癌的诊断价值

目的:探讨醛酮还原酶家族1B10(Aldo-keto reductase family 1,member B10,AKR1B10)与磷脂酰肌醇蛋白多糖-3(glypican-3,GPC-3)免疫组化检测在诊断肝细胞癌(HCC)的应用价值。方法:收集本院56例肝细胞癌,采用AKR1B10、GPC-3和联合法免疫组化染色,比较三种检测方法肝细胞癌的表达及强度。结果:三种免疫组化检测中,AKR1B10组、GPC-3组、联合组的阴性率分别为三组阳性率分别为73.21%、80.36%、91.07%,差异有统计学差异(P0.05)。结论:AKR1B10与GPC-3免疫组化检测对HCC诊断均具有高度特异性、敏感性,AKR1B10与GPC-3联合法准确率和有效率更高,对肝癌患者预后有重大意义。     

用DHPLC法研究细胞周期蛋白D1的多态性与NPC遗传易感性之间的关系

细胞周期蛋白D1是一个关键的细胞周期调节因子和候选的原癌基因 ,其失调参与多种肿瘤 ,包括鼻咽癌的发生。由于细胞周期蛋白D1的基因CCND1第 4外显子存在单个核苷酸多态A/G(A870G) ,因此可产生两种不同的转录本。有报道表明CCND1的基因型与某些肿瘤的临床表型相关。为研究细胞周期蛋白D1的基因型对中国南方散发性鼻咽癌遗传易感性是否存在影响 ,用变性高效液相色谱法 (DHPLC)和DNA测序的方法对 84例鼻咽癌患者和 91例对照的PCR产物进行细胞周期蛋白D1的基因分型。对病例组与对照组基因频率的分布分别进行Hardy Weinberg平衡检验 ,两组间基因频率的差异用 χ2 检验进行比较。结果发现 :在鼻咽癌患者中 ,细胞周期蛋白D1基因型为AA型的 (占 2 0 .2 4% )显著低于正常对照 (占38.46 % ) ,而基因型为GG型和AG型的则显著高于对照 (χ2 =6 .946 ,Pcorrected =0 .0 16 ,OR =2 .46 3,95 %CI =1.2 49～4.85 9)。这表明细胞周期蛋白D1基因的A/G多态性与鼻咽癌的遗传易感性相关 ,在鼻咽癌患者中GG和AG型基因型显著高于健康对照     

AKR1B10 confers resistance to radiotherapy via FFA/TLR4/NF-κB axis in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is one kind of human head and neck cancers with high incidence in Southern China, Southeast Asia and North Africa. In spite of great innovations in radiation and chemotherapy treatments, the 5-year survival rate is not satisfactory. One of the main reasons is resistance to radiotherapy which leads to therapy failure and recurrence of NPC. The mechanism underlying remains to be fully elucidated. Aldo-keto reductase B10 (AKR1B10) plays a role in the formation and development of carcinomas. However, its role in resistance to radiotherapy of NPC is not clear. In this research, the relationships between AKR1B10 expression and the treatment effect of NPC patients, NPC cell survival, cell apoptosis, and DNA damage repair, as well as the effect and mechanism of AKR1B10 expression on NPC radioresistance were explored. A total of 58 paraffin tissues of NPC patients received radiotherapy were collected including 30 patients with radiosensitivity and 28 patients with radioresistance. The relationships between AKR1B10 expression and the treatment effect as well as clinical characteristics were analyzed by immuno-histochemical experiments, and the roles of AKR1B10 in cell survival, apoptosis and DNA damage repair were detected using the AKR1B10 overexpressed cell models. Furthermore the mechanism of AKR1B10 in NPC radioresistance was explored. Finally, the radioresistance effect of AKR1B10 expression was evaluated by the tumor xenograft model of nude mice and the method of radiotherapy. The results showed AKR1B10 expression level was correlated with radiotherapy resistance, and AKR1B10 overexpression promoted proliferation of NPC cells, reduced apoptosis and decreased cellular DNA damage after radiotherapy. The probable molecular mechanism is that AKR1B10 expression activated FFA/TLR4/NF-κB axis in NPC cells. This was validated by using the TLR4 inhibitor TAK242 to treat NPC cells with AKR1B10 expression, which reduced the phosphorylation of NF-κB. This study suggests that AKR1B10 can induce radiotherapy resistance and promote cell survival via FFA/TLR4/NF-κB axis in NPC, which may provide a novel target to fight against radiotherapy resistance of NPC.     

醛酮还原酶家族1的C1亚型在胃癌的表达及其作用探讨

目的:研究AKR1C1(Aldo-keto reductase family 1 member C1)在胃癌中的表达,并初步探讨其在胃癌发生和发展中的作用。方法:采用胃癌组织芯片和免疫组化分析方法,检测60例胃癌患者癌组织及癌旁正常组织AKR1C1的表达;实时荧光定量PCR和蛋白免疫印迹western blot检测胃癌细胞株SGC-7901 AKR1C1的表达;在胃癌细胞株SGC-7901中转染沉默AKR1C1的sh RNA质粒及空质粒,MTT比色法检测各实验组细胞增殖。结果:组织芯片和免疫组化结果显示,与正常组织相比,胃癌组织中AKR1C1呈高表达;实时荧光定量PCR和western blot观察可以发现胃癌细胞株SGC-7901高表达AKR1C1;MTT比色法检测发现,转染沉默AKR1C1的sh RNA质粒组与空质粒对照组相比,SGC-7901细胞的增殖受到明显抑制,差异有统计学意义(P0.05)。结论:AKR1C1与癌细胞的增殖有关,可能是其参与或间接参与了癌细胞的生长周期,为胃癌的发生及细胞增值提供了新的研究思路和方向。     

中国启东肝癌高发区肝癌中AKR1C2基因异常表达及其在肝癌发生中作用(英)

已在许多肿瘤中发现AKR1C2基因的异常表达.为研究启东肝癌中AKR1C2基因异常表达的意义及其在肝癌发生中作用.通过制备兔抗人AKR1C2多克隆抗体、免疫组化、蛋白质印迹、RT-PCR、RNA印迹、原位杂交、cDNA表达芯片、免疫共沉淀、体内外致瘤试验等方法,对68例启东肝癌标本、8例正常肝组织、QGY7703启东肝癌细胞株中AKR1C2表达及作用进行分析.并研究了AKR1C2蛋白、mRNA表达与肝癌临床病理特征,侵袭性间关系.研究表明正常及癌旁肝组织中AKR1C2蛋白为膜染色,偶见弱的细胞浆染色. 95.3%肝癌显示胞浆或核染的累积型.癌及癌旁肝组织中标记指数（LI）分别为61.4±27.8, 10.2±8.7(P＜0.01).较高的LI与HCC侵袭性密切相关.蛋白质印迹显示癌组织中AKR1C2表达升高.RT-PCR显示,肝癌中AKR1C2表达指数（EI）高于癌旁及正常组织,而且存在序列差异.RNA印迹显示91.2%为上调表达.原位杂交显示肝癌细胞胞浆中染色强于癌旁及正常肝.AKR1C2过表达与肝癌转移潜能有关.AKR1C2过表达刺激QGY7703细胞中DNA合成与阻止细胞凋亡.转染AKR1C2基因的QGY7703细胞在软琼脂上集落形成能力增强,并能促进QGY7703在裸鼠体内肿瘤形成能力.cDNA表达芯片显示转染AKR1C2后导致QGY7703细胞中一些基因表达改变.AKR1C2介导NF-κB阻止抗-Fas对QGY7703的抑制作用,并且在细胞内AKR1C2能与Cdk4结合,产生免疫共沉淀.AKR1C2的异常表达在启东肝癌的发生、发展及转移中可能起重要作用.     

鼻咽癌、胃癌中抑癌基因ING1的突变检测

为探讨抑癌基因ING1是否在鼻咽癌和胃癌中存在基因突变,以确定该基因在鼻咽癌、胃癌发病过程中所起的作用,本研究运用PCR－SSCP法分别对鼻咽癌和胃癌组织ING1点突变情况进行检测;对30例鼻咽癌组织和26例胃癌组织的ING1外显子1b扩增的PCR产物进行SSCP分析,结果未发现所扩增的片段有泳运速率的改变,以上结果可以初步排除ING1在鼻咽癌和胃癌中以基因突变方式失活的可能。     

中国启东肝癌高发区肝癌中AKR1C2基因异常表达及其在肝癌发生中作用(英文)

已在许多肿瘤中发现AKR1C2基因的异常表达 .为研究启东肝癌中AKR1C2基因异常表达的意义及其在肝癌发生中作用 .通过制备兔抗人AKR1C2多克隆抗体、免疫组化、蛋白质印迹、RT PCR、RNA印迹、原位杂交、cDNA表达芯片、免疫共沉淀、体内外致瘤试验等方法 ,对 68例启东肝癌标本、 8例正常肝组织、QGY 770 3启东肝癌细胞株中AKR1C2表达及作用进行分析 .并研究了AKR 1C2蛋白、mRNA表达与肝癌临床病理特征 ,侵袭性间关系 .研究表明正常及癌旁肝组织中AKR1C2蛋白为膜染色 ,偶见弱的细胞浆染色 .95 3 %肝癌显示胞浆或核染的累积型 .癌及癌旁肝组织中标记指数(LI)分别为 61 4± 2 7 8,10 2± 8 7(P <0 . 0 1) .较高的LI与HCC侵袭性密切相关 .蛋白质印迹显示癌组织中AKR1C2表达升高 .RT PCR显示 ,肝癌中AKR1C2表达指数 (EI)高于癌旁及正常组织 ,而且存在序列差异 .RNA印迹显示 91 2 %为上调表达 .原位杂交显示肝癌细胞胞浆中染色强于癌旁及正常肝 .AKR1C2过表达与肝癌转移潜能有关 .AKR1C2过表达刺激QGY770 3细胞中DNA合成与阻止细胞凋亡 .转染AKR1C2基因的QGY770 3细胞在软琼脂上集落形成能力增强 ,并能促进QGY770 3在裸鼠体内肿瘤形成能力 .cDNA表达芯片显示转染AKR1C2后导致QGY770 3细胞中一些基因表达改变 .AKR     

Small molecule inhibitor TW-37 is tolerable and synergistic with chemotherapy in nasopharyngeal carcinoma

Chemotherapy is a crucial adjuvant therapy of advanced nasopharyngeal carcinoma (NPC). However, enhancing sensitivity and tolerance of chemotherapeutics in NPC treatment have been challenging. Both Bcl-2 and Mcl-1, 2 pro-survival proteins of Bcl-2 family, play essential roles on the chemotherapy tolerance of numerous cancers. In the present study, we explored the influences of TW-37, a small molecule inhibitor of Bcl-2 and Mcl-1, on the efficiency of chemotherapy for NPC. Oncomine cancer database shows that NPC tissues have higher expression of Bcl-2 and Mcl-1 than those of normal nasopharyngeal epithelial (NPE) tissues. And our results reveal that chemotherapeutics, Cisplatin (CDDP) and 5-Fluoracil (5-FU), result in the greater decrease of protein level of Bcl-2 and Mcl-1 in NPC cells than those in NPE cells. TW-37 does not have significant impact on the chemotherapeutics-treated NPE cell viability at a dosage that efficiently reduces chemotherapeutics-treated NPC cell viability. Moreover, impacts of TW-37 on the cell viability of chemotherapeutics-treated NPC cells are dependent on the expression of Bcl-2 and Mcl-1 in NPC cells. Further explorations suggest that TW-37 prominently promotes apoptosis in NPC cells under chemotherapeutics treatments but not in NPE cells. Meanwhile, TW-37 also remarkably reduces colony formation ability of chemotherapeutics-treated NPC cells. Importantly, in vivo models, TW-37 observably increases chemosensitivity of NPC tumors but has not markedly influence on the normal tissues in mice. In conclusion, our results point to TW-37 as a promising ancillary drug for the chemotherapy of NPC.     

High-resolution crystal structure of AKR11C1 from Bacillus halodurans: an NADPH-dependent 4-hydroxy-2,3-trans-nonenal reductase

Aldo-keto reductase AKR11C1 from Bacillus halodurans, a new member of aldo-keto reductase (AKR) family 11, has been characterized structurally and biochemically. The structures of the apo and NADPH bound form of AKR11C1 have been solved to 1.25 A and 1.3 A resolution, respectively. AKR11C1 possesses a novel non-aromatic stacking interaction of an arginine residue with the cofactor, which may favor release of the oxidized cofactor. Our biochemical studies have revealed an NADPH-dependent activity of AKR11C1 with 4-hydroxy-2,3-trans-nonenal (HNE). HNE is a cytotoxic lipid peroxidation product, and detoxification in alkaliphilic bacteria, such as B.halodurans, plays a crucial role in survival. AKR11C1 could thus be part of the detoxification system, which ensures the well being of the microorganism. The very poor activity of AKR11C1 on standard, small substrates such as benzaldehyde or DL-glyeraldehyde is consistent with the observed, very open active site lacking a binding pocket for these substrates. In contrast, modeling of HNE with its aldehyde function suitably positioned in the active site suggests that its elongated hydrophobic tail occupies a groove defined by hydrophobic side-chains. Multiple sequence alignment of AKR11C1 with the highly homologous iolS and YqkF proteins shows a high level of conservation in this putative substrate-binding site. We suggest that AKR11C1 is the first structurally characterized member of a new class of AKRs with specificity for substrates with long aliphatic tails.     

Exosomal transfer of miR-106a-5p contributes to cisplatin resistance and tumorigenesis in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), a subclass of cancers of the neck and head, is a predominant cause of cancer-associated death worldwide. Hence, there is a critical need for research into NPC-related treatment strategies. Cisplatin is a promising therapy option for NPCs and other cancers that is frequently utilized. Some patients acquire resistance to cisplatin therapy, which complicates the successful use of cisplatin treatment in NPCs. Although exosomal transfer of oncogenic miRNAs has been shown to improve recipient cell proliferation, metastasis and chemoresistance, the molecular mechanism behind this effect on NPC has yet to be fully understood. Exosomal microRNAs (miRNAs) from cisplatin-resistant cells were identified as significant mediators of chemoresistance in NPC cells in this investigation. Initially, we found that exosomal miR-106a-5p levels in the serum of chemoresistant and last-cycle patients were greater than in that of non-resistant and first-cycle patients. Also, exosomal miR-106a-5p enhanced the proliferative ability of NPC cells. Mechanistically, exosomal miR-106a-5p targets ARNT2, which further activates AKT phosphorylation, and thus promotes NPC cell proliferation, decreases apoptosis and in turn regulates tumorigenesis. We found similar results using in vivo NPC models, where exosomal miR-106a-5p through regulation of ARNT2 (aryl hydrocarbon receptor nuclear translocator 2) promoted tumorigenesis. Taken together, these findings indicate that exosomal miR-106a-5p could be a promising diagnostic biomarker and drug target for patients with NPC.