SRPX2 boosts pancreatic cancer chemoresistance by activating PI3K/AKT axis.

BACKGROUND AND AIM: This investigation was aimed at disclosing whether SRPX2 affected pancreatic cancer (PC) chemoresistance by regulating PI3K/Akt/mTOR signaling. METHODS: Totally 243 PC patients were recruited, and they were incorporated into partial remission (PR) group, stable disease (SD) group and progressive disease (PD) group in accordance with their chemotherapeutic response. PC cell lines (i.e. AsPC1, Capan2, VFPAC-1, HPAC, PANC-1, BxPC-3 and SW1990) and human pancreatic ductal epithelial cell lines (hTERT-HPNE) were also collected. RESULTS: PC patients of SD + PD group were associated with higher post-chemotherapeutic SRPX2 level than PR group, and their post-chemotherapeutic SRPX2 level was above the pretherapeutic SRPX2 level (P < 0.05). PR population showed lower SRPX2 level after chemotherapy than before chemotherapy (P < 0.05). Besides high serum SRPX2 level and SRPX2 level change before and after chemotherapy were independent predictors of poor PC prognosis. Additionally, si-SRPX2 enhanced chemosensitivity of PC cell lines, and expressions of p-PI3K, p-AKT and p-mTOR were suppressed by si-SRPX2 (P < 0.05). IGF-1 treatment could changeover the impact of si-SRPX2 on proliferation, migration, invasion and chemoresistance of PC cells (P < 0.05). CONCLUSION: The SRPX2-PI3K/AKT/mTOR axis could play a role in modifying progression and chemoresistance of PC cells, which might help to improve PC prognosis.

Regulatory effects of lncRNA ATB targeting miR-200c on proliferation and apoptosis of colorectal cancer cells.

This investigation was intended to elucidate whether long noncoding RNA (lncRNA)-activated by transforming growth factor-ß (ATB) interacting with miR-200c could mediate colorectal cancer (CRC) progression, offering potential strategies for diagnosing and treating CRC. Here totally 315 patients with CRC were recruited, and their CRC tissues and adjacent normal tissues were gathered. Concurrently, four colon cancer cell lines (ie, SW620, Lovo, HCT116, and SW480) and the human colon mucosal epithelial cell line (NCM460) were also purchased. Moreover, si-ATB, si-NC, miR-200c mimic, miR-200c inhibitor, and miR-NC were prepared for transfection into the CRC cells, and their effects on CRC cell lines were evaluated based on the conduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony formation assay, and flow cytometry assay. Eventually, the Luciferase reporter gene assay was carried out to judge if there existed a targeted relationship between ATB and miR-200c. The results of Cox regression analyses suggested that overexpressed lncRNA ATB, underexpressed miR-200c, poor tumor differentiation, lymph-vascular invasion, and perineural invasion were symbolic of shortened survival of the patients with CRC (all P < .05). Besides, transfection of pcDNA3.1-ATB and miR-200c inhibitor could boost the viability and proliferation of Lovo and SW620 cell lines (all P < .05). Meanwhile, the expressions of p53 and p21 were also reduced under treatments of pcDNA3.1-ATB and miR-200c inhibitor (P < .05). In addition, CDK2 seemed to reverse the contribution of miR-200c to intensifying viability and proliferation of Lovo and SW420 cell lines (P < .05). Furthermore, ATB might downregulate miR-200c expression by targeting it (P < .05), and CDK2 was subjected to dual regulation of both ATB and miR-200c (P < .05). In conclusion, the lncRNA ATB/miR-200c/CDK2 signaling was responsible for intensified proliferation and prohibited apoptosis of CRC cells, which might provide effective approaches for diagnosing and treating CRC.

Apatinib enhanced anti-tumor activity of cisplatin on triple-negative breast cancer through inhibition of VEGFR-2.

BACKGROUND: Triple-negative breast cancer (TNBC) was known as a fast-growing and an aggressive tumor. Cisplatin is the effective cytotoxic drug used for the treatment of TNBC. In addition, apatinib, a VEGFR2 inhibitor, exhibits antitumor activity in patients with TNBC. However, the effects of combination of apatinib with cisplatin on TNBC remain unclear. Thus, this study aimed to investigate the effects of apatinib in combination with cisplatin on MDA-MB-231 cells. METHODS: Immunohistochemistry was used to detect the expression of VEGFR2. In addition, CCK-8, flow cytometric, transwell assays were used to measure the cell proliferation, apoptosis, migration and invasion, respectively. Moreover, western blotting was used to detect the expressions of Bax, active caspase 3, p-VEGFR2, p-Akt and p-mTOR. RESULTS: VEGFR2 was significantly upreguated in patients with TNBC. In addition, the inhibitory effects of cisplatin on the proliferation, migration and invasion of MDA-MB-231 cells were enhanced by apatinib. Moreover, apatinib increased cisplatin-induced apoptosis on MDA-MB-231 cells via increasing the level of Bax and active caspase 3 and decreasing the expression of Bcl-2. Importantly, apatinib enhanced anti-tumor effect of cisplatin on MDA-MB-231 cells via inhibiting the levels of p-VEGFR2, p-Akt and p-mTOR. CONCLUSION: Our findings indicated that apatinib enhanced the anti-tumor effects of cisplatin on MDA-MB-231 cells via inhibition of VEGFR2. Thus, the combination of apatinib with cisplatin may serve as a potential approach in the treatment of patients with TNBC.

SRPX2 promotes cell migration and invasion via FAK dependent pathway in pancreatic cancer.

Sushi repeat-containing protein, X-linked 2, abbreviated as SRPX2, is a candidate downstream target protein for E2A-HLF and involved in disorders of language cortex and cognition. Recent studies have demonstrated that elevated SRPX2 exhibits crucial roles in gastric cancer, however, underlying clinical significance and biological function of SRPX2 in pancreatic ductal adenocarcinoma (PDAC), remains unclear. Data from Oncomine database showed that higher SRPX2 expression is more commonly observed in PDAC compared with normal pancreatic duct, similar results were also found in 12 matched PDAC tissue samples, 7 PDAC cell lines and a tissue microarray containing 81 PDAC specimens as demonstrated by real-time quantitative PCR and immunohistochemistry, respectively. Besides, higher SRPX2 expression was closely correlated with advanced TNM stage. Silencing of endogenous SRPX2 expression reduced abilities of cell migration and invasion of PDAC cells. Further studies revealed that SRPX2 expression in PDAC tissues significantly correlated with the phosphorylation levels of FAK, indicating that FAK dependent pathway may be account for the effect of SRPX2 on cell migration and invasion in PDAC. Collectively, this study reveals that frequently elevated SRPX2 contributes to cell migration and invasion in PDAC and SRPX2-related pathways might be a potential therapeutic target for PDAC.