Clinical Application of Single-Surgeon, Three-Port, Laparoscopic Resection for Colorectal Cancer with Natural Orifice Specimen Extraction.

Reduced-port laparoscopic surgery (RPLS) has been widely used for the radical resection of gastrointestinal tumors. Single-surgeon, three-port, laparoscopic radical resection for sigmoid colon or high rectal cancer with natural orifice specimen extraction surgery (NOSES) has the advantage of a small incision, quick postoperative recovery, and short hospital stay. Yet, there are still only a few reports on NOSES. This paper describes the indications, preoperative preparations, surgical steps, and precautions for single-surgeon, three-port, laparoscopic radical resection of the sigmoid colon and high rectal cancer, and intraoperative specimen collection through the natural orifice. The protocol focuses on the steps of radical dissection and the main technical points of resection and reconstruction. At the same time, a procedure for fixing an anvil seat by self-traction of extracorporeal silk thread, used for purse-string suture fixation after the proximal anvil was placed in the abdominal cavity, was creatively improved. This operation could effectively avoid problems such as an insufficient proximal intestinal tube, shaking off the anvil seat, and weak purse-string suture during a single operation. The surgical care had less variability and was easy to perform, effectively avoiding postoperative anastomotic leakage and bleeding due to excessive intraoperative anastomotic tissue. This surgery could be widely promoted in primary hospitals.

The efficacy of irinotecan supplementation for colorectal cancer: A meta-analysis of randomized controlled studies.

BACKGROUND: The efficacy of irinotecan as the adjunctive therapy to fluorouracil and leucovorin remains controversial in patients with colorectal cancer. We conduct this meta-analysis to explore the efficacy of irinotecan supplementation for colorectal cancer. METHODS: We have searched PubMed, EMBASE, Web of science, EBSCO, and Cochrane library databases through March 19, 2020, and included randomized controlled trials assessing the efficacy of irinotecan plus fluorouracil and leucovorin for colorectal cancer. RESULTS: Five randomized controlled trials were included in the meta-analysis. Compared with fluorouracil and leucovorin for colorectal cancer, irinotecan supplementation could significantly improve progression-free survival rate (hazard ratio = 0.72; 95% confidence interval [CI] = 0.58-0.90; P = .003), median progression-free survival (standard mean difference = -0.30; 95% CI = -0.44 to -0.15; P < .0001), overall survival rate (hazard ratio = 0.77; 95% CI = 0.66-0.90; P = .001), and objective response (risk ratio [RR] = 0.57; 95% CI = 0.49-0.66; P < .00001) and decrease progressive disease (RR = 2.10; 95% CI = 1.40-3.14; P = .0003), but revealed no obvious effect on complete response (RR = 0.88; 95% CI = 0.33-2.29; P = .79). The incidence of grade ≥3 adverse events in irinotecan supplementation group was increased compared to control group (RR = 0.67; 95% CI = 0.57-0.79; P < .00001). CONCLUSIONS: Irinotecan as the adjunctive therapy to fluorouracil and leucovorin can increase the survival and objective response of patients with colorectal cancer, but the incidence of grade ≥3 adverse events is found to be increased after irinotecan supplementation.

LncRNA CRNDE attenuates chemoresistance in gastric cancer via SRSF6-regulated alternative splicing of PICALM.

De novo and acquired resistance, which are mainly mediated by genetic alterations, are barriers to effective routine chemotherapy. However, the mechanisms underlying gastric cancer (GC) resistance to chemotherapy are still unclear. We showed that the long noncoding RNA CRNDE was related to the chemosensitivity of GC in clinical samples and a PDX model. CRNDE was decreased and inhibited autophagy flux in chemoresistant GC cells. CRNDE directly bound to splicing protein SRSF6 to reduce its protein stability and thus regulate alternative splicing (AS) events. We determined that SRSF6 regulated the PICALM exon 14 skip splice variant and triggered a significant S-to-L isoform switch, which contributed to the expression of the long isoform of PICALM (encoding PICALML). Collectively, our findings reveal the key role of CRNDE in autophagy regulation, highlighting the significance of CRNDE as a potential prognostic marker and therapeutic target against chemoresistance in GC.

LASP1 interacts with N-WASP to activate the Arp2/3 complex and facilitate colorectal cancer metastasis by increasing tumour budding and worsening the pattern of invasion.

LIM and SH3 protein 1 (LASP1) is a metastasis-related protein reported to enhance tumour progression in colorectal cancer (CRC). However, the underlying mechanism is still elusive. As the major biological and pathological functions of LASP1 are accomplished by its LIM and SH3 domains via protein-protein interactions, a yeast two-hybrid system was employed to screen novel LASP1-interacting proteins. N-WASP, a member of the Wiskott-Aldrich syndrome protein (WASP) family, was screened and identified as a LASP1-interacting protein overexpressed in CRC tissues. N-WASP could stimulate the migration and invasion of CRC cells in vitro and increase the formation of subcutaneous tumours, mesenteric implanted tumours and hepatic metastatic tumours. N-WASP could interact with and activate the Arp2/3 complex to stimulate actin polymerization, thus changing the migratory and invasive capabilities of CRC cells. The interaction of LASP1 with N-WASP did not influence the expression of N-WASP but recovered the reduced actin polymerization induced by N-WASP silencing. High N-WASP expression was detected in most clinical colorectal samples, and it was positively correlated with the expression of LASP1 and ARP3, as well as the tumour budding and pattern of invasion, but negatively correlated with host lymphocytic response. Our study suggests a new mechanism for LASP1-mediated CRC metastasis determined by exploring LASP1-interacting proteins and identifies N-WASP as a potential therapeutic target for CRC.

Transanal versus transabdominal specimen extraction in laparoscopic rectal cancer surgery: a retrospective analysis from China.

INTRODUCTION: Comparison of transanal specimen extraction (TSE) and transabdominal specimen extraction (TASE) in laparoscopic rectal surgery is still sparsely reported. Trauma, pain, scarring, and bad psychological suggestion have long been considered an inevitable outcome of surgery. For laparoscopic rectal cancer surgery, whether TSE or TASE is beneficial in terms of technical platforms, indications, contraindications, technical requirements for aseptic operation, tumor-free operation, prevention and treatment of complications still has not reached a unified consensus and standards. Recently, comparison of TSE and TASE in laparoscopic rectal surgery has still been sparsely reported. AIM: In this study, we retrospectively analyzed the short-term outcomes of TSE and TASE in laparoscopic rectal surgery in a single institution in southern China. MATERIAL AND METHODS: Patients who underwent laparoscopic radical rectal cancer surgery using either TSE or TASE were recruited. Data, including patient demographics, perioperative and postoperative variables, were analyzed retrospectively. RESULTS: Sixty-seven patients were included in this study. Thirty patients underwent TSE and 37 patients underwent TASE. The two groups were similar in demographics and tumor characteristics. Postoperative complications were similar in both groups, except that wound infection was lower for the TSE group (p = 0.122). The TSE group had a better cosmetic result with no abdominal incision and no differences in circumferential margins, distal resection margins or completeness of total mesorectal excision. CONCLUSIONS: Laparoscopic TSE is recommended in the treatment of rectal cancer with similar oncologic outcomes compared with conventional TASE. It is mini-invasive surgery and has the advantage of better cosmetic results. There is a need for further randomized studies to refine the applicability of laparoscopic TSE in rectal cancer.

Tumor-secreted dickkopf2 accelerates aerobic glycolysis and promotes angiogenesis in colorectal cancer.

Angiogenesis is a fundamental process that involves in tumor progression and metastasis. Vascular endothelial growth factor (VEGF) family and their receptors are identified as the most prominent regulators of angiogenesis. However, the clinical efficacy of anti-VEGF/VEGFR therapy is not ideal, prompting the needs to further understand mechanisms behind tumor angiogenesis. Here, we found that Dickkopf associated protein 2 (DKK2), a secretory protein highly expressed in metastatic colorectal cancer tissues, could stimulate angiogenesis via a classic VEGF/VEGFR independent pathway. Methods: DKK2 was screened out from microarray data analyzing gene expression profiles of eight pairs of non-metastatic and metastatic human colorectal cancer (CRC) tissues. Immunofluorescence histochemical staining (IHC) was used to detect the expression of DKK2 and angiogenesis in CRC tissues. Chicken chorioallantoic membrane (CAM) assay and Human umbilical vein endothelial cells (HUVEC) tubule formation assay was used for in vitro and in vivo angiogenesis study, respectively. Lactate and glucose concentration in the culture medium was measured by enzyme-linked immunosorbent assay (ELISA). Luciferase reporter assay was used to verify the interaction between miR-493-5p and the 3'UTR of DKK2. Results: DKK2 could stimulate angiogenesis via accelerating the aerobic glycolysis of CRC cells, through which lactate is produced from glucose and accumulated in tumor microenvironment. Lactate functions as the final executor of DDK2 to stimulate tube formation of endothelial cells, and blockage of lactate secretion by lactate transporter (MCT) inhibitors dramatically neutralize the progression and metastasis of CRC both in vitro and in vivo. DKK2 could cooperate with lipoprotein receptor-related protein 6, which is required for glucose uptake, and activated the downstream mTOR signal pathway to accelerate lactate secretion. In addition, the expression of DKK2 is switched on via the demethylation of miR-493-5p, which allows the dissociated of miR-493-5p from the 3'-UTRs of DKK2 and initiates its stimulatory role on CRC progression in an autocrine or paracrine manner. Conclusion: DKK2 promotes tumor metastasis and angiogenesis through a novel VEGF-independent, but energy metabolism related pathway. DKK2 might be a potential anti-angiogenic target in clinical treatment for the advanced CRC patients.

Gut microbiota-stimulated cathepsin K secretion mediates TLR4-dependent M2 macrophage polarization and promotes tumor metastasis in colorectal cancer.

Metastasis is a complex process that requires the interaction between tumor cells and their microenvironment. As an important regulator of intestinal microenvironment, gut microbiota plays a significant role in the initiation and progression of colorectal cancer (CRC), but the underlying mechanisms remain elusive. In this study, a metastasis-related secretory protein cathepsin K (CTSK) was identified as a vital mediator between the imbalance of intestinal microbiota and CRC metastasis. We implanted MC38 cells into the cecal mesentry of antibiotic-treated mice with intragastrically administration of E. coli to mimic gut microbiota imbalance. The bigger primary tumors and more liver metastatic foci were detected in the E. coli group accompanied with high LPS secretion and CTSK overexpression compared with that in the control group. CTSK contributes to the aggressive phenotype of CRC cells both in vitro and in vivo. Silencing CTSK or administration of Odanacatib, a CTSK-specific inhibitor, totally abolished the CTSK-enhanced migration and motility of CRC cells. Interestingly, the tumor-secreted CTSK could bind to toll-like receptor 4 (TLR4) to stimulate the M2 polarization of tumor-associated macrophages (TAMs) via an mTOR-dependent pathway. Recombinant CTSK could neither stimulate CRC growth and metastasis, nor induce M2 macrophage polarization in TRL4-/- mice. Meanwhile, CTSK could stimulate the secretion of cytokines by M2 TAMs including IL10 and IL17, which, in turn, promote the invasion and metastasis of CRC cells through NFκB pathway. Clinically, overexpression of CTSK in human CRC tissues is always accompanied with high M2 TAMs in the stroma, and correlated with CRC metastasis and poor prognosis. Our current research identified CTSK as a mediator between the imbalance of gut microbiota and CRC metastasis. More importantly, we illustrated a CTSK-mediated-positive feedback loop between CRC cells and TAMs during metastasis, prompting CTSK as a novel predictive biomarker and feasible therapeutic target for CRC.

High expression of uPA related to p38MAPK in esophageal cancer indicates poor prognosis.

BACKGROUND: The aim of the study was to investigate the relationship between urokinase-type plasminogen activator (uPA) and mitogen-activated protein kinase 38 (p38MAPK), and preliminarily analyze their relationship with clinical characteristics of esophageal cancer. MATERIALS AND METHODS: Immunohistochemistry and Western blot were used to detect the expressions of uPA and p38MAPK in patients with esophageal cancer. The relationship between them and clinicopathological features was analyzed by chi-squared test and Spearman correlation. Prognosis was performed using Kaplan-Meier and Cox proportional hazard models analysis. RESULTS: The expressions of uPA and p38MAPK proteins were significantly higher in esophageal squamous cell carcinoma or adenocarcinoma than in normal esophageal mucosa tissue (both P<0.0001). The expression of uPA was significantly correlated with the depth of invasion of esophageal cancer (P=0.0067), tumor size (P=0.0364), and pathological stage (P<0.0001); p38MAPK expression vs esophageal cancer tissue type (P=0.0043), esophageal cancer infiltration depth (P=0.0097), tumor size (P=0.0015), and pathological stage (P<0.0001). Both were not significantly associated with lymph node staging, gender, age, and esophageal cancer histological type. There was a positive correlation between uPA and p38MAPK expressions (r=0.7301, P=0.0104). Kaplan-Meier analysis showed that the overall survival time of patients with positive expression of uPA or p38MAPK protein was significantly shorter, and the time of recurrence or metastasis of esophageal cancer was significantly earlier in patients with uPA-positive expression. Multivariate analysis of Cox model showed that uPA, p38MAPK, and pathological staging were independent factors influencing survival. CONCLUSION: The expressions of uPA and p38MAPK may play an important role in the progression of esophageal cancer, and there is a close relationship between the two proteins, which may be one of the prognostic indicators.

The close association between IL­12Rß2 and p38MAPK, and higher expression in the early stages of NSCLC, indicates a good prognosis for survival.

Interleukin­12 receptor (IL­12R) and p38 mitogen­activated protein kinase (p38MAPK) serve an important role in non­small cell lung cancer (NSCLC). It has previously been suggested that IL­12Rß2 may be involved in key regulatory pathways and interacts with the p38MAPK signaling pathway. The present study aimed to elucidate the possible association and roles of IL­12Rß2 and p38MAPK in NSCLC. The protein expression levels of IL­12Rß2 and p38MAPK were measured in 230 NSCLC tissue samples by immunohistochemistry (IHC) and western blot analyses. In addition, an immunofluorescence assay was used to observe the expression levels of these proteins in A549 and H358 cells. The associations between IL­12Rß2, p38MAPK and clinical characteristics, were evaluated by Pearson χ2 and Spearman correlation tests. Kaplan­Meier plots (log­rank test) and Cox proportional hazard models were used to analyze overall survival (OS). Compared with in benign pulmonary tissues, the expression levels of IL­12Rß2 and p38MAPK were not demonstrated to be significantly different in I+II pathological tumor­node­metastasis (pTNM) stage NSCLC tissues; however, reduced expression was detected in III+IV pTNM stage NSCLC tissues. Analysis of the association between advanced stage pTNM and the expression of both proteins demonstrated a significantly decreased Allred score (both P<0.0001), which was confirmed by IHC and western blot analyses. The IHC results demonstrated a significant correlation between IL­12Rß2 and p38MAPK expression (r=0.415, P=0.0143). By analyzing IL­12Rß2, p38MAPK expression and clinical characteristics, it was identified that IL­12Rß2 was significantly associated with gender (P=0.0168), age (P=0.0341), histological type (P<0.0001) and pTNM stage (P<0.0001). p38MAPK demonstrated a strong association with gender (P=0.0082) and pTNM stage (P<0.0001). The results of a Kaplan­Meier analysis indicated that positive IL­12Rß2 and p38MAPK expression was associated with increased OS compared with negative protein expression. The Cox proportional hazard models revealed that IL­12Rß2 and p38MAPK predicted a long OS. To the best of our knowledge, the present study is the first to reveal a close association between IL­12Rß2 and p38MAPK, and their possible function in NSCLC progression. It further demonstrated that expression of both proteins was lower with advanced pTNM staging, whereas a high expression of both proteins was associated with improved prognosis in NSCLC.

Over expression of GPR30, indicating poor prognosis and promoting proliferation, upregulates Beclin-1 expression via p38MAPK signaling in esophageal squamous cell carcinoma progression.

BACKGROUND: Beclin-1 and GPR30, both very important proteins, have been associated with tumor development. In our pre-experiment, the co-expression of GPR30 and Beclin-1 was observed in esophageal squamous cell carcinoma (ESCC), an observation not reported in other studies. The aim of our research was to investigate the relationship of these two proteins in the further progression of ESCC. METHODS: The over expression of GPR30 and Beclin-1 proteins was observed and confirmed by immunohistochemistry and immunofluorescence arrays. By interfering with GPR30 and p38 MAPK expression in EC-109, KYSE510, and KYSE3 cell lines, MTT and a scratch wound healing assay were used to investigate the impact of the GPR30 protein on the proliferative and migrative abilities of ESCC cells. A co-immunoprecipitation assay was used to observe the interaction between the p38 MAPK and Beclin-1 proteins; meanwhile, at a different time, in each group, the GPR30, MAPK, p ERK1/2, p38 MAPK, and Beclin-1 proteins were analyzed. The correlation between GPR30, Beclin-1 expression levels, and the clinical characteristics were evaluated by Mann-Whitney and chi-square tests. Using Kaplan-Meier plots and the Cox proportional hazard model analysis, we determined overall survival (OS) and progression free survival (PFS). RESULTS: GPR30 and Beclin-1 were over expressed significantly in ESCC (both p=0.0000) and were distributed into cytoplasms the most (the former p=0.0223, latter p=0.0018). In contrast to the non-agonist group, the abilities of GPR30 in promoting cell proliferation and metastasis were observed in the agonist group, and the effects could be blocked by p38MAPK inhibitors. In further assays, GPR30 agonists, via binding to GPR30, up-regulated Beclin-1, MAPK, and p38 MAPK expression, and Beclin-1 expression was reversed in the p38MAPK inhibitor group. In the GPR30 agonist group, an interaction between p38MARK and Beclin-1 was observed, but no similar results were observed in the non-agonist group. The high expression of both GPR30 and Beclin-1 was observed with p-stage and pT advancing (both p<0.0001). In a Kaplan-Meier analysis, compared to GPR30's negative expression, high expression identified a group of patients with the shortest overall survival (OS, p=0.0072) and progression free survival (PFS, p=0.0074). The Cox proportional hazard models revealed that they predicted a short time to OS (p=0.0125). CONCLUSION: Over expression of GPR30 up-regulated Beclin-1 expression and indicated a poor prognosis and may promote ESCC development via p38 MAPK in ESCC progression.

Irisin protects against neuronal injury induced by oxygen-glucose deprivation in part depends on the inhibition of ROS-NLRP3 inflammatory signaling pathway.

Recent studies found that irisin, a newly discovered skeletal muscle-derived myokine during exercise, is also synthesized in various tissues of different species and protects against neuronal injury in cerebral ischemia. The NOD-like receptor pyrin 3 (NLRP3) inflammasome play an important role in detecting cellular damage and mediating inflammatory responses to aseptic tissue injury during ischemic stroke. However, it is unclear whether irisin is involved in the regulation of NLRP3 inflammasome activation during ischemic stroke. In the present study, PC12 neuronal cells were exposed to oxygen-glucose deprivation (OGD), exogenous irisin (12.5, 25, 50nmol/L) or NLRP3 inhibitor glyburide (50, 100, 200µmol/L) were used as an intervention reagent, NLRP3 was over-expressed or suppressed by transfection with a NLRP3 expressing vector or NLRP3-specifc siRNA, respectively. Our data showed that both irisin and its precursor protein fibronectin type III domain containing 5 (FNDC5) expression were significantly down-regulated (p<0.05); but oxidative stress and ROS-NLRP3 inflammasome signaling were activated by OGD (p<0.05); treatment with irisin or inhibition of NLRP3 reversed OGD-induced oxidative stress and inflammation (p<0.05). However, these irisin-mediated effects were blunted by over-expression NLRP3 (p<0.05). Taken together, our results firstly revealed that irisin mitigated OGD-induced neuronal injury in part via inhibiting ROS-NLRP3 inflammatory signaling pathway, suggesting a likely mechanism for irisin-induced therapeutic effect in ischemic stroke.

ZEB2 promotes tumor metastasis and correlates with poor prognosis of human colorectal cancer.

Colorectal cancer remains the most common cause of cancer-related deaths worldwide and it continues to lack an effective treatment. Here, we found that zinc finger E-box binding homeobox 2 (ZEB2) was overexpressed in several colorectal cancer cell lines and colorectal cancer specimens relative to adjacent non-cancerous tissues. Although ZEB2 has been reported to be associated with several tumors, its involvement in colorectal cancer progression remains unclear. In this study, we investigated the biological functions and molecular mechanisms of ZEB2 underlying colorectal carcinoma metastasis and angiogenesis. HCT116 colorectal cancer cells were treated with ZEB2 shRNA or recombinant ZEB2, and the expression of ZEB2 was assessed using reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblotting, respectively. Ectopic expression of ZEB2 induced proliferation and epithelial-mesenchymal transition (EMT), and increased the metastatic capacity of HCT116 cells in vitro and in vivo. Furthermore, endothelial cell tube formation and angiogenesis in chick embryo chorioallantoic membrane (CAM) were accelerated by conditioned medium from ZEB2-overexpressing HCT116 cells. Further, overexpression of ZEB2 accelerated tumor growth and angiogenesis in xenotransplantation models. However, silencing endogenous ZEB2 caused an opposite outcome. Our results provide new evidence that ZEB2 promotes the progression of colon cancer, and thereby might represent a novel therapeutic target for colorectal carcinoma.

Deregulation of miR-193b affects the growth of colon cancer cells via transforming growth factor-ß and regulation of the SMAD3 pathway.

MicroRNA-193b (miRNA-193b) is often differentially expressed and is an important regulator of gene expression in colon cancer. The aim of the present study was to determine whether miRNA-193b affects cell growth in colon cancer and to investigate the potential underlying mechanisms. Patients with colorectal cancer (CRC; n=20) and healthy volunteers (n=10) were enrolled from the Department of Gastrointestinal Surgery Center, First Affiliated Hospital of Sun Yat-Sen University (Guangzhou, China). Western blot analysis was used to evaluate the protein expression of SMAD3 and transforming growth factor-ß (TGF-ß) in the patient samples. It was determined that miRNA-193b expression was markedly elevated in the CRC tissue samples. Furthermore, silencing of miRNA-193bin SW620 CRC cells by specific inhibitors significantly reduced the cell proliferation and induced apoptosis. In addition, the downregulation of miRNA-193b significantly activated the protein expression of SMAD3 and TGF-ß, and promoted caspase-3 activity in SW620 cells. The results of the present study suggested that the deregulation of miRNA-193b may affect cell growth in colon cancer via the TGF-ß and SMAD3 signaling pathways.

The expression of ERß2, Bcl-xl and Bax in non-small cell lung cancer and associated with prognosis.

Lung cancer is now the leading cause of related death in the world, non-small lung cancer (NSCLC) in predominant type of lung cancer. In this study, we mainly discuss expression, distribution, and prognostic significance of ERß2, Bcl-xl and Bax in NSCLC. The expression of ERß2, Bcl-xl and Bax were detected by immunohistochemistry (IHC), and then the staining was evaluated and correlated with clinic and pathologic characteristics, overall survival (OS). ERß2, Bcl-xl and Bax were localized in NSCLC, and they were over-expressed all in NSCLC (P<0.05) compared with BPL tissues. IHC results showed that ERß2, Bcl-xl and Bax were not correlated with gender, age, smoking index, histological type, regional lymph node metastasis, whereas it was correlated with TNM staging of patients. In a Kaplan Meier analysis, the higher expression of ERß2, Bcl-xl and Bax was correlated with good OS. ERß2, Bcl-xl and Bax may be prognostic factors in NSCLC and useful to clinic trials.

Decreased MT1-MMP in gastric cancer suppressed cell migration and invasion via regulating MMPs and EMT.

Membrane type 1-matrix metalloproteinase (MT1-MMP) has been identified to play a significant role in several types of cancers, but little is known about the significance of MT1-MMP in gastric cancer patients. The purpose of this study is to investigate the involvement of MT1-MMP in tumor progression of gastric cancer. MT1-MMP expression levels were examined in gastric cancer tissues and cells, and normal gastric tissues and cells. The effects and molecular mechanisms of MT1-MMP expression on cell proliferation, migration, and invasion were also explored. In our results, MT1-MMP messenger RNA (mRNA) and protein expression levels were significantly increased in gastric cancer tissue. Moreover, the overexpression of MT1-MMP was positively associated with the status of clinical stage and lymph node metastasis through real-time PCR. Furthermore, knocking down MT1-MMP expression significantly suppressed the cell migration and invasion in vitro and regulated the expression of MMPs and epithelial-mesenchymal transition (EMT)-associated genes. In conclusions, our study demonstrates that MT1-MMP was overexpressed in gastric cancer tissue, and reduced expression of MT1-MMP suppressed cell migration, invasion, and through regulating the expression of MMPs and the process of EMT in gastric cancer.

Long noncoding RNA CCAT1 promotes hepatocellular carcinoma progression by functioning as let-7 sponge.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been identified as having functional roles in cancer biology and are deregulated in many cancers. The present study aimed to determine the expression, roles and functional mechanisms of a long noncoding RNA CCAT1 in the progression of hepatocellular carcinoma (HCC). METHODS: CCAT1 expression levels in 66 pairs of HCC tissues and pair-matched noncancerous hepatic tissues were tested by real-time PCR. The effects of CCAT1 on HCC cells proliferation and migration were assessed using in vitro cell proliferation and migration assays. A computational screen of microRNAs (miRNAs) target sites in CCAT1 was conducted to search for specific miRNAs binding to CCAT1. The specific binding between CCAT1 and miRNAs was confirmed by RNA immunoprecipitation assay combined with luciferase reporter assay. RESULTS: CCAT1 levels are markedly increased in HCC tissues compared with pair-matched noncancerous hepatic tissues. Up-regulation of CCAT1 is correlated with tumor size, microvascular invasion, AFP and poor prognosis. CCAT1 promotes the proliferation and migration of HCC cells. CCAT1 functions as a molecular sponge for let-7, antagonizes its functions, and leads to the de-repression of its endogenous targets HMGA2 and c-Myc. The effect of CCAT1 on HCC cell proliferation and migration is dependent upon its competitively binding to let-7. CONCLUSIONS: These data suggest that CCAT1 plays a pivotal role in HCC progression via functioning as let-7 sponge, and implicate the potential application of CCAT1 for the prognosis and treatment of HCC.

Loss of stromal caveolin-1 expression in colorectal cancer predicts poor survival.

AIM: To investigate the clinicopathological significance and prognostic value of caveolin-1 (CAV-1) in both tumor and stromal cells in colorectal cancer (CRC). METHODS: A total of 178 patients with CRC were included in this study. The correlation between CAV-1 expression and clinicopathologic features and survival was studied. RESULTS: CAV-1 expression was detected in tumor and stromal cells. The expression of stromal CAV-1 was closely associated with histological type (P=0.022), pathologic tumor-node-metastasis stage (P=0.047), pathologic N stage (P=0.035) and recurrence (P=0.000). However, tumor cell CAV-1 did not show any correlation with clinical parameters. Additionally, the loss of stromal CAV-1 expression was associated with shorter disease-free survival (P=0.000) and overall survival (P=0.000). Multivariate analysis revealed that the loss of stromal CAV-1 expression was an independent prognostic factor for both overall survival (P=0.014) and disease-free survival (P=0.006). CONCLUSION: The loss of stromal CAV-1 expression in CRC was associated with poor prognosis and could be a prognostic factor for CRC patients.

Oxamate-mediated inhibition of lactate dehydrogenase induces protective autophagy in gastric cancer cells: involvement of the Akt-mTOR signaling pathway.

Cancer cells produce a substantial amount of energy through aerobic glycolysis even in the presence of adequate oxygen. Lactate dehydrogenase (LDH), a key regulator of glycolysis, reversibly catalyzes the conversion of pyruvate to lactate. Recently, oxamate, an inhibitor of LDH, has been shown to be a promising anticancer agent. However, the detailed mechanism remains largely unclear. In this study, we demonstrate that oxamate inhibits the viability of human gastric cancer cells in a dose- and time-dependent manner. In addition, treatment with oxamate induces protective autophagy in gastric cancer cells. Moreover, autophagy inhibited by chloroquine or Beclin 1 small interfering RNA (siRNA) enhances oxamate-induced apoptosis and proliferation inhibition. Further study has shown that oxamate treatment significantly augments reactive oxygen species (ROS) production. Furthermore, cells pretreated with N-acetyl cysteine (NAC), a ROS inhibitor, display significantly reduced ROS production and attenuated oxamate-induced autophagy. Finally, functional studies reveal that the Akt-mTOR signaling pathway, a major negative regulator of autophagy, is inhibited by oxamate. Together, our results provide new insights regarding the biological and anti-proliferative activities of oxamate against gastric cancer, and may offer a promising therapeutic strategy for gastric cancer.

Susceptibility and REF1 gene polymorphism towards colorectal cancer.

Published data on the relation between REF1 polymorphism and colorectal cancer risk showed inconclusive results. The aim of this study was to derive a comprehensive estimation of the association. Data on association between REF1 polymorphism and colorectal cancer risk were summarized. The association was estimated by calculating an odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) with the fixed effects model when P > 0.1 (from heterogeneity test) or with the random effects model when P < 0.1. No significant association was revealed in any genetic model assumed for the overall analysis (OR = 1.03, 95 % CI = 0.81-1.32 for Glu/Glu vs. Asp/Asp; OR = 1.05, 95 % CI = 0.96-1.15 for Glu/Glu + Asp/Glu vs. Asp/Asp; OR = 0.97, 95 % CI = 0.76-1.23 for Glu/Glu vs. Asp/Glu + Asp/Asp; OR = 1.03, 95 % CI = 0.92-1.16 for Glu vs. Asp; OR = 1.09, 95 % CI = 0.93-1.27 for Asp/Glu vs. Asp/Asp). In Caucasian population, nor did we find a significant association. This research indicates that REF1 polymorphism is unlikely to be associated with colorectal cancer risk.

The clinicopathologic importance of serum lactic dehydrogenase in patients with gastric cancer.

BACKGROUND: To explore possible correlation between serum lactate dehydrogenase (SLDH) levels and gastric cancer. MATERIALS AND METHODS: We retrospectively reviewed 365 patients with gastric cancer. The correlation of SLDH levels with clinicopathologic features and survival rate was studied. RESULTS: SLDH levels were closely associated with the pathological (p) T stage (P = 0.011), metastasis (P = 0.012), pTNM stage (P = 0.001), and recurrence (P = 0.012). Moreover, we found a significant SLDH level difference among Borrmann type (P = 0.027), pT stage (P = 0.004), lymph node metastasis (P = 0.027), metastasis (P < 0.001), pTNM stage (P = 0.006), and recurrence (P = 0.002). In addition, we detected a significant SLDH level difference between alive and dead subgroups (P = 0.001). In addition, both univariate analysis and multivariate analysis showed that high SLDH levels were independent prognostic factor. For the subgroup with normal LDH (median point of 157.0 U/L), we detected that the subset with SLDH levels ≥157 U/L (158-245 U/L) showed poorer OS (P = 0.005) and DFS (P = 0.01) than that of ≤157 subgroup. CONCLUSIONS: Our results suggest that high SLDH level could be an independent poor prognostic biomarker. Gastric cancer patients with relative high SLDH level (158-245 U/L) were prone to develop a shorter OS and DFS.