A novel training program: laparoscopic versus robotic-assisted low anterior resection for rectal cancer can be trained simultaneously.

Background: Current expectations are that surgeons should be technically proficient in minimally invasive low anterior resection (LAR)-both laparoscopic and robotic-assisted surgery. However, methods to effectively train surgeons for both approaches are under-explored. We aimed to compare two different training programs for minimally invasive LAR, focusing on the learning curve and perioperative outcomes of two trainee surgeons. Methods: We reviewed 272 consecutive patients undergoing laparoscopic or robotic LAR by surgeons A and B, who were novices in conducting minimally invasive colorectal surgery. Surgeon A was trained by first operating on 80 cases by laparoscopy and then 56 cases by robotic-assisted surgery. Surgeon B was trained by simultaneously performing 80 cases by laparoscopy and 56 by robotic-assisted surgery. The cumulative sum (CUSUM) method was used to evaluate the learning curves of operative time and surgical failure. Results: For laparoscopic surgery, the CUSUM plots showed a longer learning process for surgeon A than surgeon B (47 vs. 32 cases) for operative time, but a similar trend in surgical failure (23 vs. 19 cases). For robotic surgery, the plots of the two surgeons showed similar trends for both operative times (23 vs. 25 cases) and surgical failure (17 vs. 19 cases). Therefore, the learning curves of surgeons A and B were respectively divided into two phases at the 47th and 32nd cases for laparoscopic surgery and at the 23rd and 25th cases for robotic surgery. The clinicopathological outcomes of the two surgeons were similar in each phase of the learning curve for each surgery. Conclusions: For surgeons with rich experience in open colorectal resections, simultaneous training for laparoscopic and robotic-assisted LAR of rectal cancer is safe, effective, and associated with accelerated learning curves.

Bromodomain and Extraterminal (BET) protein inhibition suppresses tumor progression and inhibits HGF-MET signaling through targeting cancer-associated fibroblasts in colorectal cancer.

OBJECTIVE: Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality. The bromodomain and extra-terminal domain (BET) inhibitors suppresses the gene expressions of various oncogenes and shows a good efficacy in the preclinical CRC models. We investigate the mechanism of action of BET inhibitors in CRC. METHODS: The effect of BET inhibitor (JQ1) on the HGF-MET signaling was assessed by qPCR, western blot and immunohistochemical staining in CRC and cancer-associated fibroblasts (CAFs). The effect of JQ1 on the CAFs was investigated using the primary CAFs derived from CRC tissues and induced-CAFs derived from isolating foreskin fibroblasts. The effect of JQ1 on the gene expression profile of CAFs was explored by RNA-sequence, qPCR and bioinformatic analysis. RESULTS: JQ1 decreased the mRNA and protein levels of MET in CRC cells and downregulated the mRNA and protein levels of HGF in both CRC cells and CAFs. JQ1 attenuated the pro-migratory activity of CAFs through downregulation of HGF expression in CAFs. Meanwhile, JQ1 also reduced the ability of contracting collagen gels, decreased the cell proliferation, induced G1 arrest and repressed the pro-inflammatory gene expressions in CAFs. MYC expression was suppressed by JQ1 in CAFs. Knockdown of MYC induced G1 arrest in CAFs. CONCLUSION: Our results demonstrate the inhibitory effect of BET inhibition on the HGF-MET signaling and the pro-tumor activity of CAFs, revealing a new mechanism by which BET inhibition suppresses CRC progression.

CCBE1 promotes tumor lymphangiogenesis and is negatively regulated by TGFß signaling in colorectal cancer.

Collagen and calcium-binding EGF domain-1 (CCBE1) is essential for lymphatic vascular development as it promotes vascular endothelial growth factor C (VEGFC) proteolysis. A recent study reported that CCBE1 was overexpressed in epithelial colorectal cancer (CRC) cells; however, the role of CCBE1 in tumor lymphangiogenesis and the mechanism underlying dysregulated CCBE1 expression in CRC remain undefined. Methods: The role of CCBE1 in tumor lymphangiogenesis and lymphatic metastasis was investigated using human lymphatic endothelial cells (HLECs) model in vitro, and a hindfoot lymphatic metastasis model in vivo. Immunochemistry analysis was performed to assess CCBE1 expression, prognostic value and correlation with clinicopathological characteristics in CRC. The biochemical function and transcriptional regulatory mechanism of CCBE1 were explored by western blot, qPCR, and chromatin immunoprecipitation. Results: Cancer cell-derived CCBE1 enhances VEGFC proteolysis in vitro, facilitates tube formation and migration of HLECs in vitro, and promotes tumor lymphangiogenesis and lymphatic metastasis in vivo. In addition to CRC cells, tumor stroma within CRC tissue shows high CCBE1 expression, which is associated with high lymphatic vessel density, increased lymph node metastasis and poor prognosis. Cancer-associated fibroblasts (CAFs) express and secret CCBE1, thereby contributing to VEGFC maturation and tumor lymphangiogenesis in CRC. Transforming growth factor beta (TGF-ß) downregulates the transcription and lymphangiogenic function of CCBE1 in CAFs and CRC cells through direct binding of SMADs to CCBE1 gene locus. Inactivation of the TGF-ß pathway correlates with increased CCBE1 expression in CRC. Conclusion: Our results demonstrate the protumorigenic role of CCBE1 in promoting lymphangiogenesis and lymphatic metastasis in CRC, revealing a new mechanism by which loss of TGF-ß signaling promotes CRC metastasis.

Small heat shock protein CRYAB inhibits intestinal mucosal inflammatory responses and protects barrier integrity through suppressing IKKß activity.

Alpha B-crystallin (CRYAB) is an important member of the small heat shock protein family, and plays a protective and therapeutic role in neurological inflammation. CRYAB expression was assessed in cultured HT29 and Caco-2 cells and inflamed mucosa of patients with inflammatory bowel disease (IBD) and colitis models in mice. Lentivirus-overexpressing and CRSIPR/Cas9 systems were used in different cells to upregulate and silence CRYAB expression, respectively. Cell permeable recombined fusion protein TAT-CRYAB was injected intraperitoneally into dextran sulfate sodium (DSS)- or 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice to assess its anti-inflammatory effects. CRYAB was found to be significantly decreased in the inflamed mucosa from IBD patients and DSS-induced colitis in mice, and negatively correlated with the levels of TNF-α and IL-6, respectively. Enforced expression of CRYAB suppressed expression of proinflammatory cytokines (e.g., TNF-α, IL-6, IL-1ß, and IL-8) via inhibiting the IKK complex formation, whereas lack of CRYAB expression markedly enhanced proinflammatory responses. Consistently, administration of TAT-CRYAB fusion protein significantly alleviated DSS- or TNBS-induced colitis in mice and protected intestinal barrier integrity. CRYAB regulates inflammatory response in intestinal mucosa by inhibiting IKKß-mediated signaling and may serve as a novel therapeutic approach in the treatment of IBD.

Reduced Frequency and Prognostic Significance of Ring Finger Protein 43 Nucleotide Polymorphisms in a Chinese Colorectal Cancer Cohort.

The aim of this research was to verify the mutation rate of the ring finger protein 43 (RNF43) of the transmembrane E3 ubiquitin ligase and investigate the influence of single nucleotide polymorphisms (SNPs) rs2257205 in RNF43 in a Chinese colorectal cancer (CRC) cohort. DNA from 177 diagnosed CRC patients' tissues or blood samples were extracted, amplified, and sequenced. Clinicopathological features, including age, gender, tumor location, tumor-lymph node-metastasis stage, and survival information, were analyzed. Four novel RNF43 mutations (including G659 and R117 sites) were validated in 177 CRC patients; all events were somatic frameshift mutations. Furthermore, we also found that an SNP (rs2257205) of the RNF43 X117 site was associated with overall survival (OS) instead of disease-free survival. G homozygote subjects were significantly correlated with poor OS compared with another group. Then we rescued RNF43 R117R (encoded by nucleotide CGC) and R117H (encoded by nucleotide CAC) expression in the HCT116 cells and analyzed the targets of the Wnt/ß-catenin pathway. The expression of CCND1 and c-Myc were decreased. The prognosis of CRC patients could be affected by the different functions of SNPs of RNF43.

Increased IGF2BP3 expression promotes the aggressive phenotypes of colorectal cancer cells in vitro and vivo.

Previous literatures reported insulin-like growth factor-2 messenger RNA-binding protein 3 (IGF2BP3) is a poor prognostic marker for colorectal cancer (CRC) patients. However, basic research on the effect and biological role of IGF2BP3 in CRC was still scare. Real-time quantitative polymerase chain reaction and western blot analysis were used to examine IGF2BP3 expression level in tumors and paired normal tissues from CRC patients. Tissue microarrays with 192 CRC patients were subjected to immunohistochemical staining to analyze the prognostic value of IGF2BP3. Proliferation assays, migration assays, and xenograft tumor formation in nude mice were performed to assess the biological role of IGF2BP3 in CRC cells. IGF2BP3 expression was significantly upregulated in tumor tissues compared with the matched normal tissues both in messenger RNA and protein level and was associated with worse prognosis. IGF2BP3 knockdown made cell cycle arrest to impair the proliferation ability of CRC cells and further inhibited the xenograft tumor growth in nude mice, also inhibited the migration ability of CRC cells via inducing epithelial-mesenchymal transition. Therefore, the research demonstrated that increased IGF2BP3 expression promoted the aggressive phenotypes of CRC cells. Targeted IGF2BP3 could be a novel and effective gene therapy for CRC patients to make a better prognosis.

Reduced Risk of Inflammatory Bowel Disease-associated Colorectal Neoplasia with Use of Thiopurines: a Systematic Review and Meta-analysis.

BACKGROUND AND AIMS: The association between thiopurines and colorectal neoplasia risk remains controversial in inflammatory bowel disease [IBD] patients. We performed a systematic review and meta-analysis examining this association. METHODS: A comprehensive search of the PubMed, EMBASE and Cochrane Library databases was performed to identify relevant literature. Random-effects models were applied to calculate the pooled odds ratio [OR] and relative risk [RR] with corresponding 95% confidence intervals [CIs] among case-control and cohort studies. RESULTS: Eleven cohort and 16 case-control studies involving 95397 patients were included in this study. Overall, the use of thiopurines was associated with a reduced risk of colorectal neoplasia both in case-control [OR = 0.49, 95% CI: 0.34-0.70] and cohort studies [RR = 0.96, 95% CI: 0.94-0.98]. Moreover, a protective effect of thiopurines against advanced neoplasia [high-grade dysplasia and cancer] [OR = 0.51, 95% CI: 0.31-0.84 for case-control studies; RR = 0.96, 95% CI: 0.94-0.98 for cohort studies] and colorectal cancer [CRC] [OR = 0.56, 95% CI: 0.34-0.93 for case-control studies; RR = 0.96, 95% CI: 0.94-0.98 for cohort studies] was also observed. Furthermore, when the analysis was conducted on patients at a high risk for colorectal neoplasia, the chemopreventive effect was confirmed in patients with long disease duration [> 8 years] but not in those with extensive colitis or primary sclerosing cholangitis. CONCLUSIONS: This study demonstrated that thiopurine use was associated with a reduced risk of colorectal neoplasia, advanced neoplasia and CRC in IBD patients, especially those with long disease duration [> 8 years].

Ring finger protein 152 inhibits colorectal cancer cell growth and is a novel prognostic biomarker.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. RING finger-related E3 ubiquitin ligases play a role in tumorigenesis and can function either as oncogenes or tumor suppressors based on their target proteins. Here, we show that the expression of RNF152, a ring finger protein, in CRC tissues was significantly reduced compared with adjacent non-cancerous tissues. High expression levels of RNF152 correlated with better prognosis in patients with colorectal cancer. Low expression of RNF152 correlated with lymphatic metastasis. Overexpression of RNF152 inhibited CRC cell proliferation both in vitro and in vivo by inactivating the mechanistic target of rapamycin complex 1 (mTORC1) and inducing autophagy and apoptotic cell death. This strong inhibition was dependent on the E3 ligase activity of RNF152. Ectopic expression of the RNF152-CS-mutant, which lacks E3 ligase activity, significantly restored the proliferation ability of CRC cells. Our findings showed that RNF152 inhibits colorectal cancer growth and may be a novel prognostic biomarker for the treatment of CRC.