Promoted Apoptosis In Colorectal Cancer Cells Research Articles

FIT links c-Myc and P53 acetylation by recruiting RBBP7 during colorectal carcinogenesis.

Colorectal cancer (CRC) poses one of the most serious threats to human health worldwide, and abnormally expressed c-Myc and p53 are deemed the pivotal driving forces of CRC progression. In this study, we discovered that the lncRNA FIT, which was downregulated in CRC clinical samples, was transcriptionally suppressed by c-Myc in vitro and promoted CRC cell apoptosis by inducing FAS expression. FAS is a p53 target gene, and we found that FIT formed a trimer with RBBP7 and p53 that facilitated p53 acetylation and p53-mediated FAS gene transcription. Moreover, FIT was capable of retarding CRC growth in a mouse xenograft model, and FIT expression was positively correlated with FAS expression in clinical samples. Thus, our study elucidates the role of the lncRNA FIT in human colorectal cancer growth and provides a potential target for anti-CRC drugs.

Depletion of Fibroblast Growth Factor 12 Restrains the Viability, Stemness, and Motility of Colorectal Cancer.

Background Colorectal cancer (CRC) is a leading cause of cancer-related death. CRC patients have a poor prognosis due to tumor metastasis and recurrence. Fibroblast growth factor 12 (FGF12), a member of the FGF family, is highly expressed in several cancers. However, little is known about the roles of FGF12 in CRC progression. Methods The overall survival (OS) of CRC patients was detected via Kaplan–Meier analysis. The FGF12 expression in both CRC tissues and cells was analyzed by qRT-PCR, immunohistochemistry (IHC), and western blotting (WB). LoVo and SW480 cells were transfected with shFGF12 lentivirus to silence FGF12. In vivo and in vitro experiments were performed to explore the FGF12 functions in CRC, including CCK-8, Edu, flow cytometry, Transwell, EMT, cancer stemness, and tumor xenograft experiments. Results FGF12 was upregulated in both CRC cells and tissues. High expression of FGF12 indicated a shorter OS in CRC patients. FGF12 knockdown inhibited the proliferation, invasion, stemness, and EMT of CRC cells. FGF12 knockdown promoted CRC cell apoptosis in vitro. 740 Y-P (a PI3K/AKT pathway activator) restored the proliferation, stemness, invasion, and EMT in FGF12-deficient cells and reversed LoVo cell apoptosis induced by FGF12 depletion. Depletion of FGF12 inhibited tumor growth, EMT, cancer stemness, and PI3K/AKT pathway in a xenograft mouse model. Conclusions FGF12 predicts bad clinical outcome and modulates the viability, stemness, and motility of CRC cells. Our study may provide a new insight for the diagnosis and treatment of CRC.

NDRG4 sensitizes CRC cells to 5-FU by upregulating DDIT3 expression.

The incidence of colorectal cancer (CRC) has remained high in recent years, and 5-fluorouracil (5-FU) is a vital chemotherapeutic agent for its treatment. Our previous study reported that N-myc downstream-regulated gene 4 (NDRG4) plays a tumor-suppressive role in CRC, but the mechanisms associated with NDRG4 and 5-FU chemosensitivity remain unclear. The results of the present study demonstrate that NDRG4 sensitized CRC cells to 5-FU by upregulating DNA damage inducible transcript 3 (DDIT3). NDRG4 inhibited the proliferation of CRC cells and the activation of PI3K/AKT and ERK signaling. Furthermore, NDRG4 promoted CRC cell apoptosis induced by 5-FU. Mechanistic analyses revealed that NDRG4 upregulated DDIT3 expression, and that the proapoptotic effect of NDRG4 under 5-FU treatment conditions was dependent on DDIT3. These findings support the biological value of the association between NDRG4, DDIT3 and 5-FU chemosensitivity in CRC, and may advance the clinical treatment of CRC in the future.

RETRACTED: Inhibiting microRNA-424 in bone marrow mesenchymal stem cells-derived exosomes suppresses tumor growth in colorectal cancer by upregulating TGFBR3

ObjectiveMicroRNAs (miRNAs) have been demonstrated to be differently expressed in colorectal cancer (CRC) and were identified as biomarkers and therapeutic targets for CRC. We aimed to identify the effect of microRNA-424 (miR-424) on process of CRC. MethodsExosomes were obtained from bone marrow mesenchymal stem cells (BMSCs). MiR-424, transforming growth factor-β receptor 3 (TGFBR3) vimentin, S100A4, p-Smad1 expression in tissues and cells was measured. After treated with miR-424 inhibitor or TGFBR3 overexpression plasmid, the migration, invasion, cell cycle distribution and apoptosis of Lovo cells and exosomes-transfected Lovo cells were determined. The subcutaneous tumor models were established and the tumor growth was observed. The target relation between miR-424 and TGFBR3 was confirmed. ResultsMiR-424 was upregulated while TGFBR3 was downregulated in CRC tissues. TGFBR3 was targeted by miR-424. Inhibited miR-424 or elevated TGFBR3 upregulated p-Smad1, indicating that TGFBR3 mediated the Smad1 pathway, thus regulating CRC progression. MiR-424 inhibition or TGFBR3 restoration also suppressed migration and invasion of CRC cells, arrested the CRC cells at G0/G1 phase, and promoted CRC cell apoptosis. Moreover, exosomal miR-424 from BMSCs promoted CRC development. ConclusionInhibited exosomal miR-424 from BMSCs inhibited malignant behaviors of CRC cells by targeting TGFBR3, thus suppressing the progression of CRC.

Qingjie Fuzheng Granules regulates cancer cell proliferation, apoptosis and tumor angiogenesis in colorectal cancer xenograft mice via Sonic Hedgehog pathway.

Sonic Hedgehog (SHh) signaling pathway plays a critical role in cell proliferation, apoptosis, and tumor angiogenesis in various types of malignancies including colorectal cancer (CRC). Qingjie Fuzheng Granules (QFG) is a traditional Chinese medicinal formula, which has been clinically used in various cancer treatments, including CRC. In this study, we explored the potential molecular mechanisms of QFG treatment effects on CRC via the SHh pathway. A CRC HCT-116 xenograft mouse model was utilized for all experiments. Mice were treated with intra-gastric administration of 1 g/kg of QFG or saline 6 days a week for 28 days (4 weeks). Body weight, length and shortest diameter of the tumor were measured every 3 days. At the end of the treatment, the tumor weight was measured. TUNEL staining assays were used to detect tumor apoptosis. Western blot and immunohistochemistry (IHC) assays were used to detect the expression of relative proteins. In our results, QFG inhibited the increase of tumor volume and weight, and exhibited no impact on mouse body weight. Furthermore, QFG significantly decreased the expression of SHh, Smo and Gli proteins, indicating the action of SHh signaling. Consequently, the expression of pro-proliferative survivin, Ki-67, Cyclin-D1 and CDK4 were decreased and expression of anti-proliferative p21 was increased. The pro-apoptotic Bax/Bcl-2 ratio, cle-caspase-3 and TUNEL-positive cell percentage in tumor tissues were increased. Meanwhile, the pro-angiogenic VEGF-A and VEGFR-2 expression was down-regulated. QFG inhibited CRC cell proliferation and promoted CRC cell apoptosis and tumor angiogenesis in vivo through the suppression of SHh pathway, suggesting that QFG could be a potential therapeutic drug for CRC.

LncRNA KCNQ1OT1 knockdown inhibits colorectal cancer cell proliferation, migration and invasiveness via the PI3K/AKT pathway.

Colorectal cancer (CRC) is one of the most common primary malignancies worldwide. Numerous studies have demonstrated that long non-coding RNAs (lncRNAs) are considered as crucial regulators of tumor progression. In particular, upregulation of the lncRNA KCNQ1OT1 was reported in various types of malignancy as a promoter of tumor progression. However, the role and underlying mechanism of KCNQ1OT1 in CRC remain unclear. Thus, the present study aimed to investigate the role of KCNQ1OT1 in colorectal cancer through GEPIA, reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses, and cell assays. GEPIA analysis demonstrated that high expression levels of KCNQ1OT1 in CRC tissues predicted a poor prognosis for patients with CRC. KCNQ1OT1 was overexpressed in CRC tissues and cell lines via RT-qPCR analysis. Furthermore, the results from the cell viability assay, colony formation assay, wound healing assay, invasion assay and flow cytometric analysis demonstrated that KCNQ1OT1 knockdown significantly inhibited CRC cell proliferation, migration and invasiveness, and promoted CRC cell apoptosis, leading to cell cycle arrest. Western blot analysis demonstrated that KCNQ1OT1 knockdown inhibited the PI3K/AKT signaling pathway. These results suggest that KCNQ1OT1 may act as an oncogene through the PI3K/AKT signaling pathway in CRC.

MEG3 is a prognostic factor for CRC and promotes chemosensitivity by enhancing oxaliplatin-induced cell apoptosis.

A major reason for the failure of advanced colorectal cancer (CRC) treatment is the occurrence of chemoresistance to oxaliplatin-based chemotherapy. Recently, studies have shown that long non-coding RNAs (lncRNAs) play an important role in drug resistance. Using HiSeq sequencing methods, we identified that lncRNAs show differential expression levels in oxaliplatin-resistant (OxR) and non-resistant CRC patients. RT-qPCR was then performed in tissues and serum samples, and lncRNA MEG3 was verified to be downregulated in non-responding patients and to have considerable discriminating potential to identify responding patients from non-responding patients. Moreover, decreased serum MEG3 expression was associated with poor chemoresponse and low survival rate in CRC patients receiving oxaliplatin treatment. Subsequently, OxR cell lines were established, and MEG3 was significantly downregulated in HT29 OxR and SW480 OxR cells. In addition, overexpression of MEG3 with pMEG3 reversed oxaliplatin resistance in both CRC cell lines. Flow cytometric apoptosis analysis indicated that MEG3 promoted CRC cell apoptosis. More importantly, MEG3 enhanced oxaliplatin-induced cell cytotoxicity in CRC. In conclusion, our integrated approach demonstrated that decreased expression of lncRNA MEG3 in CRC confers potent poor therapeutic efficacy, and that MEG3 promotes chemosensitivity by enhancing oxaliplatin-induced cell apoptosis. Thus, overexpression of MEG3 may be a future direction by which to develop a novel therapeutic strategy to overcome oxaliplatin resistance of CRC patients.

STAT5a-targeting miRNA enhances chemosensitivity to cisplatin and 5-fluorouracil in human colorectal cancer cells

Signal transducers and activators of transcription 5 (STAT5) has been shown to be involved in a variety of cellular processes, including survival, proliferation, invasion, angiogenesis and immune evasion and is frequently overexpressed in human solid tumors and blood malignancies. The aim of this study was to investigate the role of STAT5a in colorectal cancer (CRC) progression. We inhibited the expression of STAT5a using lentivirus-mediated artificial microRNA (miRNA) interference in vitro and investigated the viability of CRC cells by CCK-8 assay. We observed the cell viability after treatment with cisplatin (CDDP) or 5-fluorouracil (5-Fu) by CCK-8 assay, and the apoptosis induced by chemotherapy using flow cytometric analysis and Annexin V RFP staining assay. We inhibited the mRNA expression by 54% and the protein expression by 60% of STAT5 by RNA interference targeting STAT5a. Cell viability assays showed that inhibition of STAT5a did not affect the viability of SW1116 cells. However, we found that inhibition of STAT5a restored the sensitivity of SW1116 cells to CDDP and 5-Fu. In additional experiments, we found that inhibition of STAT5a significantly promoted CRC cell apoptosis by CDDP and 5-Fu. In the present study, we found that inhibition of STAT5a promotes apoptosis of CRC cells induced by chemotherapy drugs, such as CDDP or 5-Fu. These results suggest that inhibition of STAT5a may serve as a potential new target for CRC treatment.

Aspirin promotes apoptosis in a murine model of colorectal cancer by mechanisms involving downregulation of IL-6–STAT3 signaling pathway

Aspirin is associated with a reduced risk of colorectal cancer (CRC), and it showed inhibited effects on interleukin 6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway which is thought to play an important role in intestinal inflammation and the tumorigenesis of CRC. Mouse model for inflammation-related CRC was induced by a combined treatment with azoxymethane (AOM) and dextran sodium sulfate (DSS) in BALB/c mice. Effects of aspirin on tumor number and size and apoptosis of CRC cells were investigated. Key molecules of IL-6-STAT3 pathway, such as IL-6, sIL-6R, phosphorylated STAT3, and their downstream anti-apoptotic genes Bcl-2 and Bcl-xl, were assessed by ELISA and Western blot. Treatment with aspirin significantly promoted CRC cell apoptosis in AOM/DSS-induced CRC mice in vivo. The expression level of IL-6, which is an upstream molecule of STAT3 and capable of activating STAT3, was reduced in aspirin-treated mice. Furthermore, the phosphorylated form of STAT3 and the levels of STAT3's target gene products such as Bcl-xl and Bcl-2, which are essential for cell growth and survival, were also decreased in aspirin-treated mice. Our data suggested that the protective mechanisms of aspirin in CRC may be associated with its effects on induction of CRC cell apoptosis and suppression of IL-6-STAT3 signaling pathway, which implied that aspirin has a potential therapeutic activity in CRC.