TUFT1 Facilitates Metastasis,Stemness, and Vincristine Resistance in Colorectal Cancer via Activation of PI3K/AKT Pathway

Since the incidence and mortality of colorectal cancer (CRC) are increasing in recent years, the research on the pathogenesis of colorectal cancer has attracted more and more attention. Here, our results confirmed that the mRNA expression level and proteins accumulation of TUFT1 were significantly increased in CRC tissues from late-stage CRC patients (III?+?IV) (p?<?0.001), indicated by qPCR and IHC assay. The TUFT1 expression was positively correlated with tumor stage by analyzing 126 specimens from CRC patients. Next, we found that up-regulation of TUFT1 enhanced the migration and invasion of LoVo cells, whereas the down-regulation of TUFT1 observably weakened the migration and invasion of SW837 cells, indicating that TUFT1 promotes the metastasis of CRC cells. In addition, TUFT1 overexpression increased the number of mammary spheres and vincristine resistance of LoVo cells by sphere formation assay and measuring the IC50 value, suggesting the TUFT1 promotes stemness and the vincristine resistance of CRC cells. Finally, we found that TUFT1 overexpression increased p-AKT in LoVo cells, while down-regulation of TUFT1 decreased the p-AKT levels in SW837 cells. Therefore, we determined that the function of TUFT1 in CRC depends on PI3K/AKT pathway. Taken together, these data demonstrated that TUFI1 facilitates metastasis, stemness, and vincristine resistance of colorectal cancer cells via activation of PI3K/AKT pathway, which might act as a promising therapeutic target for CRC.

     

Anti-tumor effect of carrimycin on oral squamous cell carcinoma cells in vitro and in vivo

Purpose: Carrimycin is a newly synthesized macrolide antibiotic with good antibacterial effect. Exploratory experiments found its function in regulating cell physiology, proliferation and immunity, suggesting its potential anti-tumor capacity. The aim of this study is to investigate the anti-tumor effect of carrimycin against human oral squamous cell carcinoma cells in vitro and in vivo.Methods: Human oral squamous cell carcinoma cells (HN30/HN6/Cal27/HB96 cell lines) were treated with gradient concentration of carrimycin. Cell proliferation, colony formation and migration ability were analyzed. Cell cycle and apoptosis were assessed by flow cytometry. The effect of carrimycin on OSCC in vivo was investigated in tumor xenograft models. Immunohistochemistry, western blot assay and TUNEL assays of tissue samples from xenografts were performed. The key proteins in PI3K/AKT/mTOR pathway and MAPK pathway were examined by western blot.Results: As the concentration of carrimycin increased, the proliferation, colony formation and migration ability of OSCC cells were inhibited. After treating with carrimycin, cell cycle was arrested in G0/G1 phase and cell apoptosis was promoted. The tumor growth of xenografts was significantly suppressed. Furthermore, the expression of p-PI3K, p-AKT, p-mTOR, p-S6K, p-4EBP1, p-ERK and p-p38 were down-regulated in vitro and in vivo.Conclusions: Carrimycin can inhibit the biological activities of OSCC cells in vitro and in vivo, and regulate the PI3K/AKT/mTOR and MAPK pathways.     

Melatonin and hyperbaric oxygen therapies suppress colorectal carcinogenesis through pleiotropic effects and multifaceted mechanisms

Colorectal cancer (CRC) is the third most common cancer worldwide. Colorectal carcinogenesis is frequently induced by hypoxia to trigger the reprogramming of cellular metabolism and gain of malignant phenotypes. Previously, hyperbaric oxygen (HBO) therapy and melatonin have been reported to alter the hypoxic microenvironment, resulting in inhibiting cancer cell survival. Accordingly, this study tested the hypothesis whether HBO and melatonin effectively inhibited CRC carcinogenesis. In vitro results indicated that melatonin therapy significantly suppressed the malignant phenotypes, including colony formation, growth, invasion, migration and cancer stemness with dose-dependent manners in CRC cell lines through multifaceted mechanisms. Similar to in vitro study, in vivo findings further demonstrated the melatonin, HBO and combined treatments effectively promoted apoptosis (cleaved-caspase 3/ cleaved-PARP) and arrested tumor proliferation, followed by inhibiting colorectal tumorigenesis in CRC xenograft tumor model. Moreover, melatonin, HBO and combined treatments modulated multifaceted mechanisms, including decreasing HIF-1α expression, alleviating AKT activation, repressing glycolytic metabolism (HK-2/PFK1/PKM2/LDH), restraining cancer stemness pathway (TGF-β/p-Smad3/Oct4/Nanog), reducing inflammation (p-NFκB/ COX-2), diminishing immune escape (PD-L1), and reversing expression of epithelial mesenchymal transition (E-cadherin/N-cadherin/MMP9). In conclusion, melatonin and HBO therapies suppressed colorectal carcinogenesis through the pleiotropic effects and multifaceted mechanisms, suggesting melatonin and HBO treatments could be novel therapeutic strategies for CRC treatment.     

Suppression of FAM83D Inhibits Glioma Proliferation,Invasion and Migration by Regulating the AKT/mTOR Signaling Pathway

ObjectiveTo explore the mechanism by which the family with sequence similarity 83, member D (FAM83D)-mediated AKT/mTOR signaling pathway activation affects the proliferation and metastasis of glioma cells.MethodsFAM83D protein expression in glioma cells and tissues was detected by western blotting. Glioma U87 and U251 cells were selected and divided into the Mock, siNC, siFAM83D, FAM83D, MK2206 and FAM83D + MK2206 groups. Cell proliferation was assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and clone formation assays, while invasion and migration were evaluated by Transwell assays and wound healing tests. The protein expression of members of the AKT/mTOR pathway was determined via western blotting. Xenograft models were also established in nude mice to observe the in vivo effect of FAM83D on the growth of glioma.ResultsFAM83D was upregulated in glioma patients, especially in those with Stage III-IV. In addition, cells treated with siFAM83D had significant downregulation of p-AKT/AKT and p-mTOR/mTOR, with decreased proliferation and colony numbers, as well as decreased invasion and migration compared to the Mock group. However, FAM83D overexpression could activate the Akt/mTOR pathway and promote the proliferation, invasion and migration of glioma cells. Moreover, treatment with MK2206, an inhibitor of AKT, reversed the promoting effect of FAM83D on the growth of glioma cells. The in vivo experiments demonstrated that silencing FAM83D could inhibit the in vivo growth of glioma cellsConclusionFAM83D was upregulated in glioma and silencing FAM83D suppressed the proliferation, invasion and migration of glioma cells via inhibition of the AKT/mTOR pathway.     

In Vivo c-Met Pathway Inhibition Depletes Human Glioma Xenografts of Tumor-Propagating Stem-Like Cells

Solid malignancies contain sphere-forming stem-like cells that are particularly efficient in propagating tumors. Identifying agents that target these cells will advance the development of more effective therapies. Recent converging evidence shows that c-Met expression marks tumor-initiating stem-like cells and that c-Met signaling drives human glioblastoma multiforme (GBM) cell stemness in vitro. However, the degree to which tumor-propagating stem-like cells depend on c-Met signaling in histologically complex cancers remains unknown. We examined the effects of in vivo c-Met pathway inhibitor therapy on tumor-propagating stem-like cells in human GBM xenografts. Animals bearing pre-established tumor xenografts expressing activated c-Met were treated with either neutralizing anti- hepatocyte growth factor (HGF) monoclonal antibody L2G7 or with the c-Met kinase inhibitor PF2341066 (Crizotinib). c-Met pathway inhibition inhibited tumor growth, depleted tumors of sphere-forming cells, and inhibited tumor expression of stem cell markers CD133, Sox2, Nanog, and Musashi. Withdrawing c-Met pathway inhibitor therapy resulted in a substantial rebound in stem cell marker expression concurrent with tumor recurrence. Cells derived from xenografts treated with anti-HGF in vivo were depleted of tumor-propagating potential as determined by in vivo serial dilution tumor-propagating assay. Furthermore, daughter xenografts that did form were 12-fold smaller than controls. These findings show that stem-like tumor-initiating cells are dynamically regulated by c-Met signaling in vivo and that c-Met pathway inhibitors can deplete tumors of their tumor-propagating stem-like cells.     

Selenium binding protein 1 inhibits tumor angiogenesis in colorectal cancers by blocking the Delta-like ligand 4/Notch1 signaling pathway

BackgroundSelenium binding protein 1 (SELENBP1) is frequently downregulated in malignancies such as colorectal cancer (CRC), however, whether it is involved in tumor angiogenesis is still unknown.MethodsWe analyzed the expression and localization of SELENBP1 in vessels from CRC and neighboring tissues. We investigated the in vitro and in vivo activity of SELENBP1 in angiogenesis and explored the underlying mechanism.ResultsSELENBP1 was localized to endothelial cells in addition to glandular cells, while its vascular expression was decreased in tumor vessels compared to that in vessels from neighboring non-tumor tissues. Gain-of-function and loss-of-function experiments demonstrated that SELENBP1 inhibited angiogenesis in vitro, and blocked communications between HUVECs and CRC cells. Overexpression of SELENBP1 in CRC cells inhibited tumor growth and angiogenesis, and enhanced bevacizumab-sensitivity in a mouse subcutaneous xenograft model. Mechanic analyses revealed that SELENBP1 may suppress tumor angiogenesis by binding with Delta-like ligand 4 (DLL4) and antagonizing the DLL4/Notch1 signaling pathway. The inhibitory effects of SELENBP1 on in vitro angiogenesis could largely be rescued by DLL4.ConclusionThese results revealed a novel role of SELENBP1 as a potential tumor suppressor that antagonizes tumor angiogenesis in CRC by intervening the DLL4/Notch1 signaling pathway.     

Combined blockade of EGFR and glutamine metabolism in preclinical models of colorectal cancer

Improving response to epidermal growth factor receptor (EGFR)-targeted therapies in patients with advanced wild-type (WT) RAS colorectal cancer (CRC) remains an unmet need. In this preclinical work, we evaluated a new therapeutic combination aimed at enhancing efficacy by targeting cancer cell metabolism in concert with EGFR. We hypothesized that combined blockade of glutamine metabolism and EGFR represents a promising treatment approach by targeting both the “fuel” and “signaling” components that these tumors need to survive. To explore this hypothesis, we combined CB-839, an inhibitor of glutaminase 1 (GLS1), the mitochondrial enzyme responsible for catalyzing conversion of glutamine to glutamate, with cetuximab, an EGFR-targeted monoclonal antibody in preclinical models of CRC. 2D and 3D in vitro assays were executed following treatment with either single agent or combination therapy. The combination of cetuximab with CB-839 resulted in reduced cell viability and demonstrated synergism in several cell lines. In vivo efficacy experiments were performed in cell-line xenograft models propagated in athymic nude mice. Tumor volumes were measured followed by immunohistochemical (IHC) analysis of proliferation (Ki67), mechanistic target of rapamycin (mTOR) signaling (pS6), and multiple mechanisms of cell death to annotate molecular determinants of response. In vivo, a significant reduction in tumor growth and reduced Ki67 and pS6 IHC staining were observed with combination therapy, which was accompanied by increased apoptosis and/or necrosis. The combination showed efficacy in cetuximab-sensitive as well as resistant models. In conclusion, this therapeutic combination represents a promising new precision medicine approach for patients with refractory metastatic WT RAS CRC.     

Gambogenic acid induces Noxa-mediated apoptosis in colorectal cancer through ROS-dependent activation of IRE1α/JNK

BackgroundGambogenic acid (GNA), an active component of Garcinia hanburyi Hook.f. (Clusiaceae) (common name gamboge), exerts anti-inflammatory and antitumor properties. However, the underlying mechanism of GNA in colorectal cancer (CRC) is still not well understood.PurposeThis study aimed to investigate the antitumor effects and mechanisms of GNA on CRC in vitro and in vivo.MethodsCell viability, colony formation and cell apoptosis assays were performed to determine the antitumor effects of GNA. qRT-PCR and Western blotting were performed to evaluate the expression of genes or proteins affected by GNA in vitro and in vivo. HCT116 colon cancer xenografts and the APC^min/+ mice model were used to confirm the antitumor effects of GNA on CRC in vivo.ResultsGNA induced Noxa-mediated apoptosis by inducing reactive oxygen species (ROS) generation and c-Jun N-terminal kinase (JNK) activation. Moreover, GNA triggered endoplasmic reticulum (ER) stress, which subsequently activated inositol-requiring enzyme-1α (IRE1α) leading to JNK phosphorylation. ROS scavenger attenuated GNA-induced IRE1α activation and JNK phosphorylation. Knockdown of IRE1α also prevented GNA-induced JNK phosphorylation. In vivo, GNA suppressed tumor growth and progression in HCT116 colon cancer xenografts and the APC^min/+ mices model.ConclusionThese findings revealed that GNA induced Noxa-mediated apoptosis by activating the ROS/IRE1α/JNK signaling pathway in CRC both in vitro and in vivo. GNA is therefore a promising antitumor agent for CRC treatment.     

The dual PI3K/mTOR inhibitor NVP-BEZ235 induces tumor regression in a genetically engineered mouse model of PIK3CA wild-type colorectal cancer

Purpose

To examine the in vitro and in vivo efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in treatment of PIK3CA wild-type colorectal cancer (CRC).

Experimental Design

PIK3CA mutant and wild-type human CRC cell lines were treated in vitro with NVP-BEZ235, and the resulting effects on proliferation, apoptosis, and signaling were assessed. Colonic tumors from a genetically engineered mouse (GEM) model for sporadic wild-type PIK3CA CRC were treated in vivo with NVP-BEZ235. The resulting effects on macroscopic tumor growth/regression, proliferation, apoptosis, angiogenesis, and signaling were examined.

Results

In vitro treatment of CRC cell lines with NVP-BEZ235 resulted in transient PI3K blockade, sustained decreases in mTORC1/mTORC2 signaling, and a corresponding decrease in cell viability (median IC₅₀ = 9.0–14.3 nM). Similar effects were seen in paired isogenic CRC cell lines that differed only in the presence or absence of an activating PIK3CA mutant allele. In vivo treatment of colonic tumor-bearing mice with NVP-BEZ235 resulted in transient PI3K inhibition and sustained blockade of mTORC1/mTORC2 signaling. Longitudinal tumor surveillance by optical colonoscopy demonstrated a 97% increase in tumor size in control mice (p = 0.01) vs. a 43% decrease (p = 0.008) in treated mice. Ex vivo analysis of the NVP-BEZ235-treated tumors demonstrated a 56% decrease in proliferation (p = 0.003), no effects on apoptosis, and a 75% reduction in angiogenesis (p = 0.013).

Conclusions

These studies provide the preclinical rationale for studies examining the efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in treatment of PIK3CA wild-type CRC.     

Dual Pharmacological Targeting of the MAP Kinase and PI3K/mTOR Pathway in Preclinical Models of Colorectal Cancer

Background

The activation of the MAPK and PI3K/AKT/mTOR pathways is implicated in the majority of cancers. Activating mutations in both of these pathways has been described in colorectal cancer (CRC), thus indicating their potential as therapeutic targets. This study evaluated the combination of a PI3K/mTOR inhibitor (PF-04691502/PF-502) in combination with a MEK inhibitor (PD-0325901/PD-901) in CRC cell lines and patient-derived CRC tumor xenograft models (PDTX).

Materials and Methods

The anti-proliferative effects of PF-502 and PD-901 were assessed as single agents and in combination against a panel of CRC cell lines with various molecular backgrounds. Synergy was evaluated using the Bliss Additivity method. In selected cell lines, we investigated the combination effects on downstream effectors by immunoblotting. The combination was then evaluated in several fully genetically annotated CRC PDTX models.

Results

The in vitro experiments demonstrated a wide range of IC₅₀ values for both agents against a cell line panel. The combination of PF-502 and PD-901 demonstrated synergistic anti-proliferative activity with Bliss values in the additive range. As expected, p-AKT and p-ERK were downregulated by PF-502 and PD-901, respectively. In PDTX models, following a 30-day exposure to PF-502, PD-901 or the combination, the combination demonstrated enhanced reduction in tumor growth as compared to either single agent regardless of KRAS or PI3K mutational status.

Conclusions

The combination of a PI3K/mTOR and a MEK inhibitor demonstrated enhanced anti-proliferative effects against CRC cell lines and PDTX models.     

Signaling through the Phosphatidylinositol 3-Kinase (PI3K)/Mammalian Target of Rapamycin (mTOR) Axis Is Responsible for Aerobic Glycolysis mediated by Glucose Transporter in Epidermal Growth Factor Receptor (EGFR)-mutated Lung Adenocarcinoma

Oncogenic epidermal growth factor receptor (EGFR) signaling plays an important role in regulating global metabolic pathways, including aerobic glycolysis, the pentose phosphate pathway (PPP), and pyrimidine biosynthesis. However, the molecular mechanism by which EGFR signaling regulates cancer cell metabolism is still unclear. To elucidate how EGFR signaling is linked to metabolic activity, we investigated the involvement of the RAS/MEK/ERK and PI3K/AKT/mammalian target of rapamycin (mTOR) pathways on metabolic alteration in lung adenocarcinoma (LAD) cell lines with activating EGFR mutations. Although MEK inhibition did not alter lactate production and the extracellular acidification rate, PI3K/mTOR inhibitors significantly suppressed glycolysis in EGFR-mutant LAD cells. Moreover, a comprehensive metabolomics analysis revealed that the levels of glucose 6-phosphate and 6-phosphogluconate as early metabolites in glycolysis and PPP were decreased after inhibition of the PI3K/AKT/mTOR pathway, suggesting a link between PI3K signaling and the proper function of glucose transporters or hexokinases in glycolysis. Indeed, PI3K/mTOR inhibition effectively suppressed membrane localization of facilitative glucose transporter 1 (GLUT1), which, instead, accumulated in the cytoplasm. Finally, aerobic glycolysis and cell proliferation were down-regulated when GLUT1 gene expression was suppressed by RNAi. Taken together, these results suggest that PI3K/AKT/mTOR signaling is indispensable for the regulation of aerobic glycolysis in EGFR-mutated LAD cells.     

Targeting AKT1-E17K and the PI3K/AKT Pathway with an Allosteric AKT Inhibitor,ARQ 092

As a critical component in the PI3K/AKT/mTOR pathway, AKT has become an attractive target for therapeutic intervention. ARQ 092 and a next generation AKT inhibitor, ARQ 751 are selective, allosteric, pan-AKT and AKT1-E17K mutant inhibitors that potently inhibit phosphorylation of AKT. Biochemical and cellular analysis showed that ARQ 092 and ARQ 751 inhibited AKT activation not only by dephosphorylating the membrane-associated active form, but also by preventing the inactive form from localizing into plasma membrane. In endometrial PDX models harboring mutant AKT1-E17K and other tumor models with an activated AKT pathway, both compounds exhibited strong anti-tumor activity. Combination studies conducted in in vivo breast tumor models demonstrated that ARQ 092 enhanced tumor inhibition of a common chemotherapeutic agent (paclitaxel). In a large panel of diverse cancer cell lines, ARQ 092 and ARQ 751 inhibited proliferation across multiple tumor types but were most potent in leukemia, breast, endometrial, and colorectal cancer cell lines. Moreover, inhibition by ARQ 092 and ARQ 751 was more prevalent in cancer cell lines containing PIK3CA/PIK3R1 mutations compared to those with wt-PIK3CA/PIK3R1 or PTEN mutations. For both ARQ 092 and ARQ 751, PIK3CA/PIK3R1 and AKT1-E17K mutations can potentially be used as predictive biomarkers for patient selection in clinical studies.     

Overexpression of BIRC6 Is a Predictor of Prognosis for Colorectal Cancer

MethodsWe used Western blotting and immunohistochemistry to examine BIRC6 expression in 7 CRC cell lines and 126 CRC clinical samples. We determined the biological significance of BIRC6 in CRC cell lines by a lentivirus-mediated silencing method.ResultsWe reported that BIRC6 was overexpressed in CRC cell lines and clinical CRC tissues. BIRC6 overexpression was correlated with tumor size and invasion depth of CRC. BIRC6 overexpression is associated with worse overall survival (OS) (P = 0.001) and shorter disease-free survival (DFS) (P = 0.010). BIRC6 knockdown inhibited cell proliferation, arrested cell cycle at S phase, downregulated cyclin A2, B1, D1 and E1 levels, and sensitized CRC cells to chemotherapy in vitro and in vivo.ConclusionsTaken together, these data suggests that BIRC6 overexpression is a predictor of poor prognosis in colorectal cancer and BIRC6 could be a potential target of CRC therapy.     

Quercetin Inhibits Angiogenesis Mediated Human Prostate Tumor Growth by Targeting VEGFR- 2 Regulated AKT/mTOR/P70S6K Signaling Pathways

Angiogenesis is a crucial step in the growth and metastasis of cancers, since it enables the growing tumor to receive oxygen and nutrients. Cancer prevention using natural products has become an integral part of cancer control. We studied the antiangiogenic activity of quercetin using ex vivo, in vivo and in vitro models. Rat aortic ring assay showed that quercetin at non-toxic concentrations significantly inhibited microvessel sprouting and exhibited a significant inhibition in the proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Most importantly, quercetin treatment inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay. Western blot analysis showed that quercetin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, mTOR, and ribosomal protein S6 kinase in HUVECs. Quercetin (20 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that quercetin inhibited tumorigenesis by targeting angiogenesis. Furthermore, quercetin reduced the cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, mTOR and P70S6K expressions. Collectively the findings in the present study suggest that quercetin inhibits tumor growth and angiogenesis by targeting VEGF-R2 regulated AKT/mTOR/P70S6K signaling pathway, and could be used as a potential drug candidate for cancer therapy.     

Effect of pristimerin on apoptosis through activation of ROS/ endoplasmic reticulum (ER) stress-mediated noxa in colorectal cancer

BackgroundPristimerin, a natural quinonemethid triterpenoid found in different spp. of Celastraceae and Hippocrateaceae families, has been reported to exhibit potent antitumor activities against colorectal cancer (CRC). However, the mechanisms underlying pristimerin-induced apoptosis in CRC is not clear.PurposeThis study aimed to investigate the mechanisms of pristimerin-induced apoptosis against CRC in vitro and in vivo.MethodsCell viability and cell apoptosis analyses were conducted to assess the effects of pristimerin on CRC. Western blotting was performed to detect the expression of proteins affected by pristimerin in vitro and in vivo. HCT116 colon cancer xenografts and APC^min/+ mouse models were used to evaluate the anti-CRC effect of pristimerin in vivo.ResultsOur data showed that pristimerin induced apoptosis by regulating proapoptotic proteins of which Noxa showed higher expression. Pristimerin triggered reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress signaling activation. Pristimerin significantly elevated the expression of ER stress-related proteins, resulting in activation of the IRE1α and c-Jun N-terminal kinase (JNK) signal pathway through the formation of the IRE1α-TRAF2-ASK1 complex. Pristimerin exhibited apoptosis-inducing activities in HCT116 colon cancer xenografts and APC^min/+ mice.ConclusionBoth in vitro and in vivo data demonstrated that pristimerin induced Noxa expression and apoptosis through activation of the ROS/ER stress/JNK axis in CRC. Thus, pristimerin may be a promising antitumor agent for CRC.     

AKT Inhibitors Promote Cell Death in Cervical Cancer through Disruption of mTOR Signaling and Glucose Uptake

Background

PI3K/AKT pathway alterations are associated with incomplete response to chemoradiation in human cervical cancer. This study was performed to test for mutations in the PI3K pathway and to evaluate the effects of AKT inhibitors on glucose uptake and cell viability.

Experimental Design

Mutational analysis of DNA from 140 pretreatment tumor biopsies and 8 human cervical cancer cell lines was performed. C33A cells (PIK3CAR88Q and PTENR233*) were treated with increasing concentrations of two allosteric AKT inhibitors (SC-66 and MK-2206) with or without the glucose analogue 2-deoxyglucose (2-DG). Cell viability and activation status of the AKT/mTOR pathway were determined in response to the treatment. Glucose uptake was evaluated by incubation with ¹⁸F-fluorodeoxyglucose (FDG). Cell migration was assessed by scratch assay.

Results

Activating PIK3CA (E545K, E542K) and inactivating PTEN (R233*) mutations were identified in human cervical cancer. SC-66 effectively inhibited AKT, mTOR and mTOR substrates in C33A cells. SC-66 inhibited glucose uptake via reduced delivery of Glut1 and Glut4 to the cell membrane. SC-66 (1 µg/ml-56%) and MK-2206 (30 µM-49%) treatment decreased cell viability through a non-apoptotic mechanism. Decreases in cell viability were enhanced when AKT inhibitors were combined with 2-DG. The scratch assay showed a substantial reduction in cell migration upon SC-66 treatment.

Conclusions

The mutational spectrum of the PI3K/AKT pathway in cervical cancer is complex. AKT inhibitors effectively block mTORC1/2, decrease glucose uptake, glycolysis, and decrease cell viability in vitro. These results suggest that AKT inhibitors may improve response to chemoradiation in cervical cancer.     

Facile construction of fused benzimidazole-isoquinolinones that induce cell-cycle arrest and apoptosis in colorectal cancer cells

Colorectal cancer (CRC) is one of the most frequent, malignant gastrointestinal tumors, and strategies and effectiveness of current therapy are limited. A series of benzimidazole-isoquinolinone derivatives (BIDs) was synthesized and screened to identify novel scaffolds for CRC. Of the compounds evaluated, 7g exhibited the most promising anti-cancer properties. Employing two CRC cell lines, SW620 and HT29, 7g was found to suppress growth and proliferation of the cell lines at a concentration of ～20?µM. Treatment followed an increase in G₂/M cell cycle arrest, which was attributed to cyclin B1 and cyclin-dependent kinase 1 (CDK1) signaling deficiencies with simultaneous enhancement in p21 and p53 activity. In addition, mitochondrial-mediated apoptosis was induced in CRC cells. Interestingly, 7g decreased phosphorylated AKT, mTOR and 4E-BP1 levels, while promoting the expression/stability of PTEN. Since PTEN controls input into the PI3K/AKT/mTOR pathway, antiproliferative effects can be attributed to PTEN-mediated tumor suppression. Collectively, these results suggest that BIDs exert antitumor activity in CRC by impairing PI3K/AKT/mTOR signaling. Against a small kinase panel, 7g exhibited low affinity at 5?µM suggesting anticancer properties likely stem through a non-kinase mechanism. Because of the novelty of BIDs, the structure can serve as a lead scaffold to design new CRC therapies.