Epigenetic regulation of RARB overcomes the radio-resistance of colorectal carcinoma cells via cancer stem cells.

Cancer stem cells (CSCs) are able to survive after cancer therapies, leading to cancer progression and recurrence in colorectal carcinoma (CRC). Therapies targeting CSCs are believed to be promising strategies for efficiently eradicating cancers. This study was to investigate that how retinoic acid receptor beta (RARB) affected the biological characteristics of CSCs and radio-resistance in CRC and the epigenetic mechanism. The sensitivity of CSCs isolated from HCT116 cells to radiotherapy was reduced compared with the parental cells. Using database querying, we found that RARB was one of the most significantly downregulated gene in radio-resistant cells in CRC. Also, RARB was poorly expressed in our isolated CSCs, and overexpression of RARB inhibited the properties of CSCs and enhanced radiotherapy sensitivity. Mechanistically, the methylation of RARB was higher in CSCs compared with HCT116 cells, which was significantly reduced after the application of DNA methylation inhibitor 5-azacytidine (5-azaC). DNA methyltransferases (DNMT1) was found to be recruited into the RARB promoter. 5-AzaC treatment inhibited DNMT1 activity and improved radiotherapy sensitivity by promoting RARB expression. Our results imply that inhibition of DNMT1 can display a new mechanism for the epigenetic mediation of RARB in radio-resistant CRC.

VSNL1 Promotes Cell Proliferation, Migration, and Invasion in Colorectal Cancer by Binding with COL10A1.

OBJECTIVE: The study aimed to explore the role of VSNL1/COL10A1 axis in colorectal cancer. METHODS: The differential-expressed mRNA in colorectal cancer tissues and adjacent tissues were analyzed through GEO database and GEPIA database. The target genes of mRNA were predicted through the Starbase database, and the targeting relationship of mRNA was verified by co-IP assay. The expressions of VSNL1 and COL10A1 were detected by RT-PCR and immunohistochemistry. Cell viability and proliferation were detected by CCK8 assay and EdU assay, respectively. Cell migration and invasion were detected by transwell assay. The expression of related proteins was detected by western blot. RESULTS: VSNL1 was significantly overexpressed in colorectal cancer tissues compared with adjacent tissues. In addition, downregulation of VSNL1 could inhibit the proliferation, migration, and invasion of colorectal cancer cells. The co-IP experiment indicated that VSNL1 could bind with COL10A1. Further studies demonstrated that upregulation of COL10A1 could promote colorectal cells proliferation, migration, invasion, and reverse the effect of sh-VSNL1 on colorectal cancer cells. CONCLUSION: VSNL1 could promote the proliferation, migration, and invasion of colorectal cancer by targeting COL10A1. VSNL1 might be a potential target for colorectal cancer treatment.

Paired-like homeodomain transcription factor 2 strengthens chemoresistance in colorectal cancer by activating the Wnt/ß-catenin axis.

The purpose of this study was to determine the mechanism of paired-like homeodomain transcription factor 2 (PITX2) in the chemoresistance of colorectal cancer (CRC) via the upregulation of the Wnt/ß-catenin axis. CRC cells were persistently exposed to increasing 5-fluorouracil (5-FU) concentrations to establish 5-FU-resistant cells. Functional assays were conducted to examine cell viability, proliferation, and cell cycle. After the transfection of small interfering (si)-negative control and si-PITX2 in 5-FU-resistant cells, the effects of PITX2 depletion in these cells were assessed. Notably, expression of PITX2, Wnt-3a, and ß-catenin, and the relation between PITX2 and Wnt-3a were verified. Additionally, an inhibitor or an activator of the Wnt/ß-catenin axis was added into cells to detect the variance of the 5-FU-resistant cells. Eventually, xenograft transplantation was applied to confirm the effect of PITX2 knockdown on CRC chemoresistance to 5-FU. 5-FU-resistant CRC cells were successfully established, in which CRC cell viability, proliferation, and cell cycle were all enhanced, while PITX2 knockout led to reversed results, indicating that resistance to 5-FU in CRC was restricted. Furthermore, our findings revealed that PITX2 upregulated the Wnt/ß-catenin axis. The inactivation of the Wnt/ß-catenin axis resulted in the reduction of resistance to 5-FU in CRC cells; while activation of the Wnt/ß-catenin axis reversed the reduced resistance to 5-FU in CRC cells caused by PITX2 knockout. Additionally, xenograft transplantation further confirmed that PITX2 knockdown reduced the resistance of HCT-116 cells to 5-FU. This study clarified that PITX2 enhanced resistance to 5-FU in CRC upregulating the Wnt/ß-catenin axis.

LncRNA TTN-AS1 sponges miR-376a-3p to promote colorectal cancer progression via upregulating KLF15.

AIMS: Long non-coding RNAs (lncRNAs) play key roles in regulating multiple cancers. TTN-AS1 was reported to function in several human malignancies. However, the biological function of TTN-AS1 in colorectal cancer (CRC) has not been explored. In this study, we aimed to investigate the role and the underlying mechanisms of TTN-AS1 in CRC progression. MAIN METHODS: RT-qPCR was used to detect the expression levels of TTN-AS1, miR-376a-3p and KLF15 in colorectal cancer tissues and cells. CCK-8, colony formation, flow cytometry and transwell assays were performed to determine the cell proliferation, apoptotic rate and invasion ability. Target genes were predicted using bioinformatics methods. si-RNA and miRNA inhibitor were transfected into CRC cells to explore the underlying mechanisms. Tumor xenografts were created to confirm the function of TTN-AS-1 in vivo. KEY FINDINGS: TTN-AS1 upregulation was observed both in CRC tissues and cell lines. Functional investigation showed that knockdown of TTN-AS1 inhibited CRC cell proliferation and invasion, while enhanced cell apoptosis. Bioinformatics analysis identified miR-376a-3p as a target of TTN-AS1. Transfection of miR-376a-3p inhibitor mitigated the alterations induced by TTN-AS1 knockdown. Moreover, TTN-AS1 positively regulated KLF15 via sponging miR-376a-3p. Additionally, these findings were supported by in vivo experiments. SIGNIFICANCE: In conclusions, TTN-AS1 promoted CRC proliferation and invasion through miR-376a-3p/KLF15 axis. Our findings suggested that TTN-AS1 might be a potential therapeutic target in CRC treatment.

High expression of ZBED1 affects proliferation and apoptosis in gastric cancer.

BACKGROUND: ZBED1 (zinc finger BED-type containing 1) is a transcription factor. However, its expression, role and clinical significance in cancer are unclear. The purpose of this study is to investigate the expression of ZBED1 and its effect on the proliferation of gastric cancer (GC). METHODS: Quantitative PCR was used to detect the mRNA level of ZBED1 in GC tissues and normal gastric tissues. Proliferation and colony formation assays were conducted when ZBED1 was expressed ectopically or silenced by constructed vectors. Moreover, chemotherapy-drug induced apoptosis rates were examined by flow cytometry when ZBED1 was expressed ectopically or silenced. RESULTS: The mRNA level of ZBED1 was significantly elevated in 10 out of 11 cases of GC tumor tissue specimens. Results of our analysis derived from a public clinical microarray database suggest that a high expression of ZBED1 predicts a poor outcome. ZBED1 promotes cell proliferation and colony formation. Moreover, ZBED1 decreased the chemosensitivity of GC cells. CONCLUSIONS: ZBED1 expression is up-regulated in GC cells. ZBED1 promotes proliferation and decreases the chemosensitivity of GC cells. ZBED1 may be a potential therapeutic target and predictive biomarker in gastric cancer.

Transcatheter arterial chemoembolization plus sorafenib versus transcatheter arterial chemoembolization alone to treat advanced hepatocellular carcinoma: a meta-analysis.

BACKGROUND: Many studies have combined sorafenib with transcatheter arterial chemoembolization (TACE) to treat patients with advanced hepatocellular carcinoma (HCC), but the results are disputable. Thus, we conducted this meta-analysis to assess the efficacy and safety of the combination treatment in patients with advanced HCC. METHODS: Clinical data were collected from a computer search of literature published from January 2009 to June 2016 in PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang and the China Science and Technology Journal Database (CSTJ). The final analysis included 14 studies and 1670 patients. The primary endpoints were overall survival (OS), the objective response rate (ORR) and the disease control rate (DCR). RESULTS: The combination group exhibited significantly more improvement than the group treated with TACE alone in ORR (RR =1.62, 95% confidence interval (CI) = 1.34-1.94, p < 0.00001), DCR (RR = 1.43, 95% CI = 1.26-1.62, p < 0.00001), 0.5-year OS (OR = 2.60, 95% CI = 1.57-4.29, p = 0.0002) and 1-year OS (OR = 1.88, 95% CI =1.39-2.53, p < 0.0001). The incidence of adverse events from combination therapy was increased compared to that from treatment with TACE alone, and the most commonly reported adverse events were fatigue, hand-foot skin reaction and diarrhoea, which were bearable. CONCLUSIONS: The meta-analysis indicated that combination therapy is safe and efficient for clinical application.

Survival changes in Patients with Synovial Sarcoma, 1983-2012.

Background: Synovial sarcoma (SyS) is a rare malignancy that typically invades the extremities and occurs predominantly in adolescents. Studies on incidence and survival in SyS that were based on a large population had not been reported yet. Methods: To evaluate changes in incidence and survival in SyS over three decades, we accessed data on SyS cases in each decade between 1983 and 2012 (1983-1992, 1993-2002, and 2003-2012) from the Surveillance, Epidemiology, and End Results (SEER) database. The survival difference between decades, age groups, sexes, race, pathologic types, sites, stages and socioeconomic status (SES) over three decades were accessed by comparing Kaplan-Meier curves. Results: We located 2,070 SyS cases in 18 SEER registry regions between 1983 and 2012. Our study demonstrated that the incidence of SyS per 1,000,000 continued to increase from 0.906 to 1.348 to 1.548 in the total population and in most age groups and that the age of incidence peak was 15-29 years in three decades. But, the survival of patients with SyS did not significantly improve throughout the three decades, with 5-year survival rates of 69.4%, 61.1% and 60.5% respectively (p > 0.05). Interestingly, the widening survival gaps among races, sexes, pathological types and various SES over time were observed, with narrowing p values. Conclusions: This study demonstrated the increasing incidence and unimproved survival rates across three decades in a large sample, indicating the urgency for further development of diagnosis, improving health care providers' awareness of SyS and lead to the development of novel treatments.

Quantitative assessment of caveolin-1 G14713A polymorphism and cancer susceptibility in the Asian population.

PURPOSE: The relationship between caveolin-1 (CAV1) G14713A polymorphism and cancer susceptibility remains inconclusive. The current meta-analysis was performed on the basis of a systematic search in electronic databases for a more precise estimation of the associations. METHODS: Odds ratio (OR) with 95% confidence interval (CI) was used to estimate the pooled effect. RESULTS: A total of 12 studies including 4,994 cases and 5,606 controls were involved in this meta-analysis. In the overall analysis, CAV1 G14713A polymorphism was significantly associated with an increased risk of cancer (A vs G: OR =1.77, 95% CI: 1.49-2.10, P het<0.01; [AA + AG] vs GG: OR =2.03, 95% CI: 1.64-2.53, P het<0.01; AA vs [AG + GG]: OR =1.72, 95% CI: 1.40-2.12, P het<0.01; AA vs GG: OR =2.24, 95% CI: 1.69-2.98, P het<0.01; AG vs GG: OR =1.98, 95% CI: 1.62-2.41, P het<0.01). Subgroup analysis by cancer type showed that CAV1 G14713A polymorphism was associated with an increased risk of digestive system cancer and other cancer types. CONCLUSION: Our findings suggest that CAV1 G14713A polymorphisms may modify the risk of cancer, especially digestive system cancer. However, further well-designed studies are warranted to validate this association.

Antitumor activity of chloroquine in combination with Cisplatin in human gastric cancer xenografts.

PURPOSE: To investigate the antitumor activity and mechanism of chloroquine (CQ) in combination with cisplatin (DDP) in nude mice xenografted with gastric cancer SGC7901 cells. MATERIALS AND METHODS: 35 cases of gastric cancer patients with malignant ascites were enrolled and intraperitoneal cisplatin injection was performed. Ascites were collected before and 5 days after perfusion for assessment of autophagy levels in cancer cells. In addition, 24 tumor-bearing mice were randomly divided into control, DDP, CQ and CQ + DDP groups. RESULTS: In 54.3% (19/35) of patients the treatment was therapeutically effective (OR), 5 days after peritoneal chemotherapy, 13 patients had the decreased ascites Beclin-1 mRNA levels. In 16 patients who had NR, only 2 cases had decreased Beclin-1 (P=0.001). Compared with the control group, the xenograft growth in nude mice in the DDP group was low, and the inhibition rate was 47.6%. In combination with chloroquine, the inhibition rate increased to 84.7% (P<0.01). The LC3-II/I ratio, and Beclin1 and MDR1/P-gp expression were decreased, while caspase 3 protein levels increased (P<0.05). CONCLUSIONS: Antitumor ability of cisplatin was associated with autophagy activity and chloroquine can enhance chemosensitivity to cisplatin in gastric cancer xenografts nude mice.

Changing patterns of Serum CEA and CA199 for Evaluating the Response to First-line Chemotherapy in Patients with Advanced Gastric Adenocarcinoma.

BACKGROUND: This study was designed to investigate the value of CEA and CA199 in predicting the treatment response to palliative chemotherapy for advanced gastric cancer. MATERIALS AND METHODS: We studied 189 patients with advanced gastric cancer who received first-line chemotherapy, measured the serum CEA and CA199 levels, used RECIST1.1 as the gold standard and analyzed the value of CEA and CA199 levels changes in predicting the treatment efficacy of chemotherapy. RESULTS: Among the 189 patients, 80 and 94 cases had increases of baseline CEA (≥5 ng/ml) and CA199 levels (≥ 27U/ml), respectively. After two cycles of chemotherapy, 42.9% patients showed partial remission, 33.3% stable disease, and 23.8% progressive disease. The area under the ROC curve (AUC) for CEA and CA199 reduction in predicting effective chemotherapy were 0.828 (95%CI 0.740-0.916) and 0.897 (95%CI 0.832-0.961). The AUCs for CEA and CA199 increase in predicting progression after chemotherapy were 0.923 (95%CI 0.865-0.980) and 0.896 (95%CI 0.834-0.959), respectively. Patients who exhibited a CEA decline ≥24% and a CA199 decline ≥29% had significantly longer PFS (log rank p=0.001, p<0.001). With the exception of patients who presented with abnormal levels after chemotherapy, changes of CEA and CA199 levels had limited value for evaluating the chemotherapy efficacy in patients with normal baseline tumor markers. CONCLUSIONS: Changes in serum CEA and CA199 levels can accurately predict the efficacy of first-line chemotherapy in advanced gastric cancer. Patients with levels decreasing beyond the optimal critical values after chemotherapy have longer PFS.

Paclitaxel-loaded trimethyl chitosan-based polymeric nanoparticle for the effective treatment of gastroenteric tumors.

Gastroenteric cancer is one of the most prevalent cancers and is responsible for most cancer-related deaths worldwide. Paclitaxel (PTX), a classical microtubule inhibitor, is indicated in the treatment of gastric/gastroenteric cancers. In the present study, trimethyl chitosan (TMC)-loaded PTX (TMC-PTX) was prepared and evaluated for its therapeutic effect in gastric cancers. A spherical shaped nanosized TMC-PTX particle was formed with high loading capacity (~30%) for PTX. The nanoparticles (NPs) showed a sustained release pattern (~70%) for up to 96 h of study period. The positively charged NPs were preferentially internalized by Caco-2 cells. TMC-PTX inhibited the gastric cell proliferation with an IC50 value of 0.6 µg in NCI-N87 cells while it was 1.26 µg in the SGC-7901 cell line after 24 h exposure. The apoptosis assay (Annexin V/PI) showed a large presence of cells in the early and late apoptosis chamber, while cell cycle analysis showed a marked G2/M phase arrest (50-60%) in NCI-N87 and SGC-7901 cell lines indicating its potent anti-proliferative effect. The in vivo antitumor study in NCI-N87 and SGC-7901 bearing xenograft model showed a superior chemotherapeutic efficacy for TMC-PTX NP. The NP group significantly reduced the tumor growth with no obvious sign of systemic side-effects (safety). Collectively, our results suggest that the microtubule inhibitory effect of PTX-loaded polymer NP could be a promising system for the treatment of gastroenteric cancers.

Coexpression of SFRP1 and WIF1 as a prognostic predictor of favorable outcomes in patients with colorectal carcinoma.

Colorectal tumorigenesis is ascribed to the activity of Wnt signaling pathway in a ligand-independent manner mainly through APC and CTNNB1 gene mutations and in a ligand-dependent manner through low expression of Wnt inhibitors such as WNT inhibitory factor 1 (WIF1) and secreted frizzled related protein 1 (SFRP1). In this study we found that WIF1 protein expression was increased and SFRP1 was decreased significantly in CRC tissue versus normal tissue, and high expression of WIF1 was associated with big tumor diameters and deep invasion, and loss of SFRP1 expression was associated with the left lesion site, deep invasion, and high TNM stage. Among the four expression patterns (WIF+/SFRP1+, WIF+/SFRP1-, WIF-/SFRP1+, and WIF-/SFRP1-) only coexpression of WIF1 and SFRP1 (WIF+/SFRP1+) was associated with favorable overall survival, together with low TNM stage, as an independent prognostic factor as shown in a multivariate survival model. The results indicated that WIF1 seemed to play an oncogenic role, while SFRP1 seemed to play an oncosuppressive role although both of them are secreted Wnt antagonists. Coexpression of SFRP1 and WIF1, rather than SFRP1 or WIF1 alone, could be used, together with low TNM stage, as a prognostic predictor of favorable outcomes in CRC.

Modulation effects of cordycepin on the skeletal muscle contraction of toad gastrocnemius muscle.

Isolated toad gastrocnemius muscle is a typical skeletal muscle tissue that is frequently used to study the motor system because it is an important component of the motor system. This study investigates the effects of cordycepin on the skeletal muscle contractile function of isolated toad gastrocnemius muscles by electrical field stimulation. Results showed that cordycepin (20 mg/l to 100 mg/l) significantly decreased the contractile responses in a concentration-dependent manner. Cordycepin (50 mg/l) also produced a rightward shift of the contractile amplitude-stimulation intensity relationship, as indicated by the increases in the threshold stimulation intensity and the saturation stimulation intensity. However, the most notable result was that the maximum amplitude of the muscle contractile force was significantly increased under cordycepin application (122±3.4% of control). This result suggests that the skeletal muscle contractile function and muscle physical fitness to the external stimulation were improved by the decreased response sensitivity in the presence of cordycepin. Moreover, cordycepin also prevented the repetitive stimulation-induced decrease in muscle contractile force and increased the recovery amplitude and recovery ratio of muscle contraction. However, these anti-fatigue effects of cordycepin on muscle contraction during long-lasting muscle activity were absent in Ca2+-free medium or in the presence of all Ca2+ channels blocker (0.4 mM CdCl2). These results suggest that cordycepin can positively affect muscle performance and provide ergogenic and prophylactic benefits in decreasing skeletal muscle fatigue. The mechanisms involving excitation-coupled Ca2+ influxes are strongly recommended.