Has_circ_0048764 promotes breast cancer progression by sponging miR-578 and regulating HMGA2 expression.

BACKGROUND: Circular RNAs (circRNAs) function as important regulators in the progression of cancers. The role of circRNA_0048764 (circ_0048764) in the development of breast cancer (BC) remains inconclusive. This work investigates the biological function and molecular mechanism of circ_0048764 in BC. METHODS: Quantitative real-time PCR (qRT-PCR) was conducted to measure the expression levels of circ_0048764, microRNA-578 (miR-578) and high mobility group AT-hook 2 (HMGA2) mRNA. The viability of BC cells was examined by cell counting kit 8 (CCK-8) assay. Besides, cyclin D1, proliferating cell nuclear antigen (PCNA) and HMGA2 expression levels were detected by western blot. The migrative and invasive capability of BC cells were probed by transwell assay. The relationships between miR-578 and circ_0048764 or HMGA2 3'-UTR were validated by dual-luciferase reporter gene assay. RESULTS: Circ_0048764 was highly expressed in BC tissues and cells, which was significantly associated with tumor size (≥2 cm), lymph node status (positive), and higher TNM stage of BC patients. Circ_0048764 depletion suppressed the proliferative, migrative, and invasive abilities of BC cells, which was rescued by transfection of miR-578 inhibitors. The binding sites were verified between circ_0048764 and miR-578. HMGA2 was identified to be a target of miR-578 in BC cells, and circ_0048764 positively regulated HMGA2 expression in BC cells via repressing miR-578. CONCLUSION: Circ_0048764 promotes BC cell growth, migration and invasion via absorbing miR-578 and up-regulating HMGA2.

MicroRNA-124-3p.1 promotes cell proliferation through Axin1-dependent Wnt signaling pathway and predicts a poor prognosis of triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is one subtype of breast cancer, which is characterized by an aggressive disease. It is commonly accompanied with extremely poor prognosis because of no available molecularly targeted therapy. Thus, understanding the detailed molecular mechanisms of TNBC is urgently needed. METHODS: The levels of Axis inhibition protein 1 (Axin1), Cyclin D1, c-Myc, and miR-124-3p.1 were measured by quantitative real-time PCR (qRT-PCR). Furthermore, the breast cancer cell proliferation was measured by CCK-8 assay, colony formation assays, and EdU staining. Xenograft model was used to show the tumor genesis of breast cancer cells. The regulatory function of miR-124-3p.1 on Wnt/ß-catenin signaling activation through directly targeting Axin1 was proven using qRT-PCR, Western blot analysis, and dual-luciferase reporter assay. To further assess the clinical significance of miR-124-3p.1 in the prognosis of breast cancer patients, we performed Kaplan-Meier survival analysis and log-rank tests. RESULTS: miR-124-3p.1 expression was elevated in advanced TNBC patients, and high miR-124-3p.1 predicts poor overall survival in TNBC patients. Further data showed that miR-124-3p.1 downregulation diminished, while miR-124-3p.1 upregulation increased the growth of TNBC cells in vitro and in vivo. Finally, we proved that miR-124-3p.1 exerted its function via targeting tumor suppressor gene Axin1 and activating the Wnt signaling pathway. CONCLUSION: In summary, all the results demonstrate that miR-124-3p.1 promotes TNBC cell growth by controlling Axin1, suggesting that targeting miR-124-3p.1 might offer an effective therapeutic strategy for TNBC in the future.

Heterogeneous nuclear ribonucleoprotein M promotes the progression of breast cancer by regulating the axin/ß-catenin signaling pathway.

Despite significant progress in the treatment of breast cancer due to advances in surgery, cytotoxic agents, and endocrine therapy, the prognosis for patients has not improved much. Accumulated evidence indicates that heterogeneous nuclear ribonucleoprotein M (hnRNPM) and Wnt/ß-catenin function as tumor oncogenes in the progression of many cancers. The present study aimed to explore whether HnRNPM/ß-catenin signaling molecules might serve as a genetic target for breast cancer treatment. To shed light on this issue, quantitative real-time polymerase chain reaction (qRT-PCR) detection, Western blotting, and immunohistochemical staining were performed. The hnRNPM is expressed at a much higher level in breast cancer tissues and cell lines than in noncancerous tissues and cell lines. In vitro studies revealed that overexpressed hnRNPM promoted cell proliferation and colony formation but inhibited cell apoptosis. In vivo results demonstrated that upregulation of hnRNPM dramatically increased breast cancer xenograft tumor growth. Western blotting and immunofluorescence studies revealed that hnRNPM markedly activated the Wnt/ß-catenin pathway and catalyzed its translocation from the cytoplasm to the nucleus by targeting axin, a negative regulator of Wnt/ß-catenin signaling in MCF-7 and KPL-4 cells. Elevated levels of c-Myc and cyclin D1 were observed when MCF-7 and KPL-4 cells were transfected with a hnRNPM vector. These findings indicate that the hnRNPM/axin/ß-catenin signaling pathway acts as an oncogenic promoter in the progression of breast cancer, suggesting that hnRNPM may be a potential target for the treatment of this disease.

Can GSTM1 and GSTT1 polymorphisms predict clinical outcomes of chemotherapy in gastric and colorectal cancers? A result based on the previous reports.

BACKGROUND: Gastric and colorectal cancers remain the major causes of cancer-related death. Although chemotherapy improves the prognosis of the patients with gastrointestinal cancers, some patients do not benefit from therapy and are exposed to the adverse effects. The polymorphisms in genes including GSTM1 and GSTT1 have been explored to predict therapeutic efficacy; however, the results were inconsistent and inconclusive. MATERIALS AND METHODS: A systematic review and meta-analysis was performed by searching relevant studies about the association between the GSTM1 and GSTT1 polymorphisms and chemotherapy efficacy in gastrointestinal cancers in databases such as PubMed, EMBASE, Web of Science, Chinese National Knowledge Infrastructure, and Wanfang database up to January 10, 2016. Subgroup analyses were also performed according to ethnicity, cancer type, evaluation criteria, study type, chemotherapy type, and age. RESULTS: A total of 19 articles containing 3,217 cases were finally included. Overall analysis suggested that no significance was found between overall toxicity, neurotoxicity, neutropenia, gastrointestinal toxicity, tumor response, and progression-free survival, and the polymorphisms in GSTM1 and GSTT1, while GSTM1 polymorphism associated with overall survival (OS; hazard ratio =1.213, 95% confidence interval =1.060-1.388, P=0.005). Subgroup analyses suggested that neurotoxicity was associated with GSTM1 polymorphism in the Asian population, neutropenia was associated with GSTM1 polymorphism in palliative chemotherapy and older patients (mean age >60 years), and tumor response was associated with GSTT1 polymorphism in gastric cancer and responders defined by complete and partial responses. Meanwhile, GSTM1 was associated with OS in Caucasians, Asians, those with colorectal cancer, and patients with mean age <60 years. GSTT1 polymorphism was also associated with OS in Caucasians and patients with mean age >60 years. CONCLUSION: The polymorphisms in GSTM1 and GSTT1 did not associate with the chemotherapy-related toxicity in gastrointestinal cancers, while GSTT1 polymorphism associated with OS, and further well-designed, larger-scale epidemiological studies are needed to validate our results.

Association between transforming growth factor-ß1 expression and the clinical features of triple negative breast cancer.

The aim of the present study was to investigate the association between the expression levels of transforming growth factor-ß1 (TGF-ß1) and the clinical pathological characteristics and prognosis of triple negative breast cancer (TNBC) through study of TNBC patient tissue samples. The biological effects of TGF-ß1 on TNBC cells and the potential signal transduction pathway are additoinally investigated. Immunohistochemistry was utilized to investigate expression changes of the positive rate of TGF-ß1 in the TNBC, compared with the non-TNBC group, to explain the association between TGF-ß1 and clinical pathological characteristics and prognosis. MDA-MB-231 cells were treated with TGF-ß1 and subsequently the invasion and migration abilities, and the expression of proteins in certain signaling pathways were assessed before and after the treatment. Positive expression of TGF-ß1 was observed in 52.5% of TNBC tissue samples, which was higher than that observed in non-TNBC group (27.5%). High levels of TGF-ß1 expression were not significantly associated age, menopausal status, family history of cancer or tumor size; however, tumor histological grade and axillary lymph node metastasis were significantly associated (P<0.05). In addition, when the TGF-ß1 expression levels are higher, the 5-year disease-free survival rate is lower. TGF-ß1 expression promoted the invasion and migration of MDA-MB-231 cells, and the expression of Smad2 protein and P38 protein was increased, indicating that Smad2 protein and the P38 signaling pathway may serve an important role in TNBC.

miR-935 promotes gastric cancer cell proliferation by targeting SOX7.

Gastric cancer is the most common cancer in the world, miRNAs have been demonstrated to play critical role in the development and progression of gastric cancer, such as miR-7, miR-217 and miR-335. Here, we found miR-935 was upregulated in gastric cancer tissues and cells. Overexpression of miR-935 promoted cell proliferation and tumorigenesis in vitro determined by MTT analysis, colony formation analysis, BrdU cell proliferation analysis and soft agar growth analysis, knockdown of miR-935 reduced these effects. Tumor suppressor sex-determining region Y-box 7 (SOX7) was the direct target of miR-935, overexpression of miR-935 inhibited SOX7 expression, but promoted the levels CCND1 and C-MYC which promotes cell proliferation and tumorigenesis, knockdown of miR-935 increased SOX7 level, and inhibited CCND1 and C-MYC expression. Synchronous knockdown of miR-935 and SOX7 promoted cell proliferation and tumorigenesis in vitro, confirming miR-935 regulated gastric cancer cell proliferation by inhibiting SOX7. In summary, we found miR-935 contributed to cell proliferation of gastric cancer through targeting SOX7.

Smad4 acts as tumor suppressor by antagonizing lymphangiogenesis in colorectal cancer.

Vascular endothelial growth factor-C (VEGF-C) is considered a vital promoter to tumor lymphangiogenesis. Smad4 is an important downstream mediator of transforming growth factor beta (TGF-ß) signaling pathway. Smad4 is regarded as a tumor suppressor in colon cancer, but its role in lymphangiogenesis in colorectal cancer is still unclear. In the present study, we investigated the potential inhibiting effect of Smad4 in lymphangiogenesis, and its correlation with VEGF-C secretion in colon cancer. We investigated endogenous Smad4 expression in 7 human colorectal cancer cell lines, and found that six of colon cancer cell lines existed with loss of Smad4. Expression of Smad4 in SW480 cell line is extremely low. SW480 cells were used to establish a Smad4 over-expression model. We investigated the relationship between Smad4 and VEGF-C expression in SW480 cells and found that Smad4 can inhibit the expression of VEGF-C. In an in vitro assay, we found that overexpression of Smad4 can reduce migration and invasion ability in SW480 cells, but had no effect on cell proliferation. Interestingly, Smad4 definitely inhibited the growth in an in vivo assay, and the volumes of transplanted tumors which originated from Smad4 overexpressing SW480 cells in nude mice were smaller than those of normal SW480 cells. In addition, we also demonstrated that Smad4 can inhibit lymphangiogenesis in vivo by immunohistochemistry. In summary, our findings provide molecular evidence that Smad4 may reduce lymphangiogenesis of colon cancer cell by attenuating VEGF-C secretion and act as tumor suppressor by inhibiting migration, invasion and tumorigenicity.

[Correlation between characteristics of lymph node metastases and prognosis in pancreatic cancer treated with pancreaticoduodenectomy].

OBJECTIVE: To study the correlation between characteristics of lymph node metastases and prognosis in pancreatic cancer treated with pancreaticoduodenectomy. METHODS: The clinicopathological data of consecutive series of 122 patients who underwent resection for adenocarcinoma of the pancreas with lymphadenectomy in our hospital were reviewed in this study. The number of metastatic lymph nodes, lymph node metastasis ratio, lymph node levels, and other clinocopathological factors were analyzed by Kaplan-Meier method and Cox proportional hazard model, and their correlation with prognosis was also analyzed. RESULTS: 122 patients met the inclusion criteria and entered the study. There were 90 patients (73.8%) with lymph node metastases. Median (range) metastatic lymph node number was 7 (1-28) for the entire cohort, and median (range) metastatic lymph node ratio was 21.1% (3.6%-62.2%). The numbers of patients with lymph nodes metastases to levels 1, 2, 3 were 39 (43.3%), 40 (44.4%), and 11 (12.2%), respectively. Univariate analysis suggested that the maximum diameter of tumor, lymph node metastases, number, ratio, level, distant metastases and adjuvant chemotherapy were significantly related to survival in the entire cohort (P < 0.05). The maximum diameter of tumor, lymph node metastasis number, ratio, level, and adjuvant chemotherapy were significantly related to the survival in node-positive patients (P < 0.05). Multivariate analysis suggested that the diameter of tumor >2 cm, lymph node metastases, metastatic lymph node number >2, ratio >20%, level >1, and without adjuvant chemotherapy were independent risk factors of survival in the entire cohort (P < 0.05). The maximum diameter of tumor >2 cm, metastatic lymph node number >2, ratio >20%, level >1 and without adjuvant chemotherapy were independent risk factors of survival in node-positive patients (P < 0.05 for all). CONCLUSIONS: The three indexes, metastatic number, ratio and extent of lymph nodal involvement are statistically significant prognostic factors in pancreatic cancer, which can complement the existing lymph node metastasis staging. The standardized pancreaticoduodenectomy combined with proper lymphodenectomy provides an important basis for a correct prognostic evaluation.