Epithelial-mesenchymal transition and metastasis of colon cancer cells induced by the FAK pathway in cancer-associated fibroblasts

Objective

The role and mechanism of tetrathiomolybdate (TM) in cancer-associated fibroblasts (CAFs) in colon cancer using three-dimensional (3D) culture were investigated, and the associations between the focal adhesion kinase (FAK) pathway and epithelial–mesenchymal transition (EMT) in CAFs were explored.

Methods

A 3D co-culture model of colon cancer LOVO cells with CAFs and normal fibroblasts (NFs) was established using Matrigel as a scaffold material. The differential expression of LOXL2 (lysyl oxidase-like 2) in the supernatant of CAFs and NFs was determined using ELISA, and expression levels of EMT-related proteins and FAK signaling pathway-related proteins were determined using western blot.

Results

LOXL2 levels secreted by CAFs were higher compared with that secreted by NFs. In the CAF + LOVO group, compared with the LOVO group, E-cadherin expression decreased significantly, while N-cadherin and F-PAK expression increased significantly. TM results were opposite compared with the above results.

Conclusions

CAFs stimulate EMT in human colon cancer LOVO cells by secreting LOXL2 to activate the FAK signaling pathway, thereby promoting tumor metastasis. TM inhibited the occurrence of EMT in the CAF-induced colon cancer LOVO cell line, thereby reducing the invasion and metastasis of colon cancer cells.

[Efficacy and safety of ombitasvir/paritaprevir/ritonavir and dasabuvir combined with ribavirin in Asian adult patients with chronic HCV genotype 1b infection and compensated cirrhosis]

Objective: To evaluate the efficacy and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) 25/150/100 mg once daily and dasabuvir (DSV) 250 mg twice daily combined with ribavirin in adult patients of Mainland China with chronic HCV genotype 1b infection and compensated cirrhosis. Methods: An open-label, multicenter, phase 3 clinical trial study was conducted in mainland China, Taiwan, and South Korea. Adult patients with compensated cirrhosis (Metavir score =F4) who were newly diagnosed and treated for hepatitis C virus genotype 1b infection with ombitasvir/paritaprevir/ritonavir and dasabuvir combined with ribavirin for 12 weeks were included. Assessed SVR rate of patients obtained at 12 and 24 weeks after drug withdrawal. Efficacy and safety were evaluated in patients who received at least one time study drugs. Results: A total of 63 patients from mainland China were enrolled, 62 of whom (98.4%) had a baseline Child-Pugh score of 5 points. The overall rate of SVR12 and SVR24 in patients was 100% (95% CI: 94.3% to 100.0%). Most of the adverse events that occurred were mild. The incidence of common (≥10%) adverse events and laboratory abnormalities included elevated total bilirubin (36.5%), weakness (19.0%), elevated unconjugated bilirubin (19.0%) and conjugated bilirubin (17.5%), and anemia (14.3%). Three cases (4.8%) of patients experienced Grade ≥ 3 adverse events that were considered by the investigators to be unrelated to the study drug. None patients had adverse events leading to premature drug withdrawal. Conclusion: Mainland Chinese patients with chronic HCV genotype 1b infection and compensated cirrhosis who were treated with OBV/PTV/r plus DSV combined with RBV for 12 weeks achieved 100 % SVR at 12 and 24 weeks after drug withdrawal. Tolerability and safety were good, and majority of adverse events were mild.

RRS1 silencing suppresses colorectal cancer cell proliferation and tumorigenesis by inhibiting G2/M progression and angiogenesis

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Ribosome biogenesis regulatory protein homolog (RRS1) is an essential factor involved in ribosome biogenesis, while its role in CRC remains largely unclear. Here, we found that RRS1 expression was significantly higher in CRC tissues compared with adjacent normal tissues. RRS1 High expression also predicted poor overall survival of CRC patients. Knockdown of RRS1 induced the G2/M cell cycle arrest, apoptosis and suppressed the proliferation of RKO and HCT-116 CRC cells. Furthermore, angiogenesis was also reduced in CRC cells after RRS1 knockdown. In addition, suppression of RRS1 blunted the tumor formation of CRC cells in nude mice. At the molecular level, silencing of RRS1 decreased the expression of M-phase inducer phosphatase 3 (CDC25C), Cyclin-dependent kinase 1 (CDK1), antigen KI-67 (KI67) and increased the protein level of cyclin-dependent kinase inhibitor 1 (CDKN1A) and tumor suppressor p53 (p53). Taken together, our findings provide evidence that RRS1 may promote the development of colon cancer. Therefore, targeting RRS1 may be a promising therapeutic strategy for CRC patients.

Genetic variability of XRCC1 influences the treatment outcome of gastric cancer

We aimed to investigate the role of XRCC1 codon 194 (Arg>Trp), 280 (Arg>His), and 399 (Arg>Gln) polymorphisms in response to chemotherapy and the overall survival of gastric cancer patients. A total of 172 patients were recruited for our study between January 2010 and March 2012. Genotyping of the three XRCC1 codons was carried out by restriction fragment length polymorphism polymerase chain reaction. By logistic regression analysis, we found that the Trp/Trp genotype of XRCC1 194 (Arg>Trp) showed a stronger association with complete or partial response to chemotherapy compared to the Arg/Arg genotype, and the adjusted odds ratio (95%CI) was 0.17 (0.05-0.58). Moreover, the Trp/Trp genotype was associated with a higher risk of death than that with the Arg/Arg genotype based on multivariate Cox proportional hazard regression analysis, and the adjusted hazard ratio (95%CI) was 4.08 (1.20-14.19). In conclusion, we found that the XRCC1 194 (Arg>Trp) polymorphism was correlated with a better response to chemotherapy and a low risk of death in patients with gastric cancer.

Impact of enteral nutrition on postoperative immune function and nutritional status

We studied the effects of enteral nutrition (EN) support initiated 1 week before surgery on postoperative nutritional status, immune function, and inflammatory response in gastric cancer patients. A total of 200 gastric cancer patients were randomly divided into two groups: EN starting 1 week before surgery (study group) and EN starting early after surgery (control group). The two groups received EN support, following different therapeutic schedules, until the 9th day after operation. In the patients, body weight, skinfold thickness, upper-arm circumference, white blood cell count, albumin, prealbumin, C-reactive protein, peripheral immunoglobulins (IgA, IgG, and IgM), T lymphocyte subsets, interleukin-6, and tumor necrosis factor-α were measured 10 days before and after surgery and on the first day after surgery. There was no statistically significant difference in the results of recovery time of passage of gas by anus, abdominal distension, stomachache, blood glucose, hepatic and renal functions, and electrolytes between the two groups of patients (P > 0. 05). Adverse reactions occurred to both groups at 1 and 2 days after operation. Such conditions was improved after the intravenous drip rate was adjusted. The albumin and prealbumin levels of the patients in both groups decreased at 1 day after operation (P < 0. 05). The levels rose when the research was finished (P < 0. 05). The prealbumin level of the study group was higher than that of the control group at 10 days after operation (P < 0. 05). The IgG level of the study group was higher than that of the control group at 10 days after operation (P < 0. 05). The two groups of inflammatory reaction indicators of the study group were lower than those of the control group at 10 days after operation (P < 0. 05). This study indicates that appropriate preoperative EN support for gastric cancer patients can improve their postoperative nutritional status and immune function, can reduce inflammatory response, and is more conducive to the recovery of patients.

Osteopontin knockdown suppresses the growth and angiogenesis of colon cancer cells

AIM: To investigate the effects of osteopontin (OPN) gene expression knockdown on colon cancer Lovo cells in vitro.

METHODS: Four candidate small interfering RNA (siRNA) constructs targeting the OPN gene and a scrambled control sequence (NC-siRNA) were synthesized and inserted into a pGPU6/GFP/Neo expression vector. After confirmation by restriction enzyme digestion and DNA sequencing, the recombinant plasmids were subsequently transfected into a human colon cancer cell line (Lovo) using a liposome transfection method. Stably transfected cells were maintained with G418 selection and referred to as Lovo-OPN-1, -2, -3, -4, and Lovo-NC cells. Knockdown efficiency of each of the four siRNA constructs was determined by real-time reverse transcription polymerase chain reaction assays and western blotting, and the construct with the most effective silencing was used for subsequent experiments. Cell proliferation, adhesion, and Matrigel invasion assays were performed to analyze the effects of OPN knockdown in stably transfected Lovo cells. The levels of four angiogenic factors, namely vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator were detected by enzyme-linked immunosorbent assays (ELISA).

RESULTS: Recombinant vectors containing OPN-specific and scrambled siRNA sequences were successfully constructed and stably transfected into Lovo cells. Compared with the control Lovo and Lovo-NC cells, the levels of OPN mRNA and protein expression in Lovo-OPN-1, -2, -3, and -4 were significantly reduced (all P < 0.05), with the most efficient reduction observed in Lovo-OPN-4 cells (P < 0.05). Relative to untransfected Lovo cells, OPN mRNA expression levels in Lovo-NC and Lovo-OPN-4 cells were 1.008 ± 0.067 and 0.160 ± 0.023, respectively. The relative OPN protein expression levels in Lovo, Lovo-NC, and Lovo-OPN-4 cells were 3.024 ± 0.211, 2.974 ± 0.630, and 0.121 ± 0.008, respectively. Moreover, transfection with the scrambled sequence had no effect on the expression of OPN. After 24, 48, 72, and 96 h of cultivation, absorption values at 450 nm to assess proliferation of Lovo-OPN-4 cells were 0.210 ± 0.017, 0.247 ± 0.024, 0.314 ± 0.037, and 0.359 ± 0.043, respectively, which were significantly lower than those of Lovo (0.244 ± 0.031, 0.313 ± 0.024, 0.513 ± 0.048 and 0.783 ± 0.051) and Lovo-NC cells (0.241 ± 0.029, 0.309 ± 0.022, 0.563 ± 0.023, and 0.735 ± 0.067) (all P < 0.05). The absorption values at 595 nm, which were measured in a cell adhesion assay, showed that adhesion of Lovo-OPN-4 cells (0.215 ± 0.036) was significantly decreased compared to Lovo (0.490 ± 0.037) and Lovo-NC cells (0.462 ± 0.043) (P < 0.05). The number of invasive Lovo-OPN-4 cells (16.1 ± 1.9) was also significantly decreased compared to Lovo (49.9 ± 5.4) and Lovo-NC cells (48.8 ± 4.5) (P < 0.05). ELISA assays showed significant reductions in Lovo-OPN-4 cells compared to Lovo and Lovo-NC cells with regard to the expression of VEGF (1687.85 ± 167.84 ng/L vs 2348.54 ± 143.80 ng/L and 2284.39 ± 138.62 ng/L, respectively), MMP-2 (2966.07 ± 177.36 μg/L vs 4084.74 ± 349.54 μg/L and 4011.41 ± 424.48 μg/L, respectively), MMP-9 (3782.89 ± 300.64 μg/L vs 5062.90 ± 303.02 μg/L and 4986.38 ± 300.75 μg/L, respectively) and uPA (1152.69 ± 120.79 μg/L vs 1380.90 ± 147.25 μg/L and 1449.80 ± 189.92 μg/L, respectively) (all P < 0.05).

CONCLUSION: Knockdown of OPN gene expression suppresses colon cancer cell growth, adherence, invasion, and expression of angiogenic factors.