A predictive nomogram developed and validated for gastric cancer patients with triple-negative tumor markers

Aim: To predict the prognosis of gastric cancer patients with triple-negative tumor markers. Materials & methods: Prognostic factors of the nomogram were identified through univariate and multivariate Cox regression analyses. Calibration and receiver operating characteristic curves were used to assess accuracy. Decision curve analysis and concordance indexes were utilized to compare the nomogram with the pathological tumor, node, metastasis stage. Results: A nomogram incorporating log odds of positive lymph nodes, tumor size and lymphocyte-to-monocyte ratio was constructed. The calibration and receiver operating characteristic curves (area under the curve >0.85) showed high accuracy in predicting overall survival. The concordance indexes (0.832 vs 0.760; p < 0.001) and decision curve analysis demonstrated that the nomogram was superior to the pathological tumor, node, metastasis stage. Conclusion: A prediction and risk stratification nomogram has been developed and validated for gastric cancer patients with triple-negative tumor markers.

MiR-301a transcriptionally activated by HIF-2α promotes hypoxia-induced epithelial-mesenchymal transition by targeting TP63 in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is one of the deadliest cancers worldwide. PC metastasis involves a complex set of events, including epithelial-mesenchymal transition (EMT), that increase tumor cell invasiveness. Recent evidence has shown that hypoxia is a major EMT regulator in pancreatic cancer cells and facilitates metastasis; however, the mechanisms remain elusive.

AIM

To investigate the role of miR-301a in hypoxia-induced EMT in PC cells.

METHODS

Real-time PCR and Western blot analysis were used to detect the expression of miR-301a and EMT markers in PDAC cells cultured in hypoxic and normoxic conditions. Western blot analysis was used to detect the expression of EMT markers in PDAC cells with miR-301a overexpression. Wound healing assay and Transwell assay were used to detect the migration capabilities of PDAC cells with miR-301a overexpression and knockout. Luciferase assay was used to detect the miR-301a promoter and the 3' untranslated region activity of TP63. Orthotopic PC mouse models were used to study the role of miR-301a in metastasis of PDAC cells in vivo. In situ hybridization assay was used to detect the expression of miR-301a in PDAC patient samples (adjacent paratumor and paired tumor tissues).  .

RESULTS

Hypoxic environment could directly promote the EMT of PC cells. The expression level of miR-301a was increased in a HIF2α dependent manner in hypoxia-cultured CFPAC-1 and BxPC-3 cells. Overexpression of miR-301a enhanced the hypoxia-induced EMT of PC cells, while knocking out miR-301a result in the suppression of hypoxia-induced EMT. TP63 was a direct target of miR-301a and involved in the metastatic process of PC cells. Furthermore, miR-301a upregulation facilitated PDAC distant metastasis and lymph node metastasis in vivo. Additionally, miR-301a overexpression was indicative of aggressive clinicopathological behaviors and poor prognosis.

CONCLUSION

The newly identified HIF-2α-miR301a-TP63 signaling pathway may play a crucial role in hypoxia-induced EMT in PDAC cells.

Downregulation of miR-301a-3p sensitizes pancreatic cancer cells to gemcitabine treatment via PTEN

BACKGROUND

We previously showed that miR-301a-3p affects the invasion and migration abilities of pancreatic cancer cells. Here, we explore the role of miR-301a-3p in chemoresistance, which represents a major obstacle in cancer treatment.

METHODS

We tested the effects of miR-301a-3p ongemcitabine resistance in cytotoxicity assays in vitro and in vivo. We used quantitative real-time PCR (qRT-PCR) to measure miR-301a-3p expression in wild-type and gemcitabine-resistant pancreatic cancer cells. We performed Western blot, qRT-PCR, and luciferase and rescue assays to confirm the direct target of miR-301a-3p.

RESULTS

The overexpression and inhibition of miR-301a-3p promoted and reversed, respectively, gemcitabine resistance in pancreatic cancer cells in vitro. The role of miR-301-3p in chemoresistance was dependent on PTEN. The suppression of miR-301-3p expression sensitized pancreatic cancer cells to gemcitabine chemotherapy in a xenograft mouse model.

CONCLUSION

MiR-301a-3p confers resistance to gemcitabine by regulating the expression of PTEN. The co-delivery of miR-301a-3p and gemcitabine might be an effective therapeutic regimen for patients with pancreatic cancer.

Downregulation of the N-myc downstream regulated gene 1 is related to enhanced proliferation, invasion and migration of pancreatic cancer

The N-myc downstream regulated gene 1 (NDRG1) is differently expressed in human malignancies according to the tumor type. We investigated the expression of NDRG1 in pancreatic cancer tissues and cell lines as well as how it affects tumor growth, invasion and migration in pancreatic cancer cells. Experimental groups included NDRG1 overexpression and knockdown pancreatic cancer cell lines. Lentivirus-based empty vector transfected cells (NC group) were considered control groups. Proliferation, invasion and migration related proteins such as STAT3, MMPs, PTEN, PI3K/AKT were assessed by CCK-8, Transwell assay and western blotting. Efficient NDRG1 overexpression results in reduced cell proliferation, invasion and migration. Inversely, downregulation of NDRG1 promoted proliferation, invasion and migration. We also found NDRG1 could deactivate p-STAT3, PI3K, p-AKT, MMP2, MMP9 and activate PTEN. NDRG1 is a potential anti-oncogene. Its upregulation significantly decreases pancreatic cancer tumorigenesis, likely by inhibiting STAT3 and the PI3K/AKT signaling pathway.

MicroRNA-301a-3p promotes pancreatic cancer progression via negative regulation of SMAD4

BACKGROUND

Aim to determine the clinicopathological and prognostic role of miR-301a-3p in pancreatic ductal adenocarcinoma(PDAC), to investigate the biological mechanism of miR-301a-3p in vitro and in vivo.

METHODS

By tissue microarray analysis, we studied miR-301a-3p expression in PDAC patients and its clinicopathological correlations as well as prognostic significance. qRT-PCR was used to test miR-301a-3p expression in PDAC tissues and cell lines. Functional experiments including in vitro and in vivo were performed.

RESULTS

Significantly higher expression of miR-301a-3p were found in PDAC patients with lymph node metastasis and advanced pathological stages and identified as an independent prognostic factor for worse survival. In PDAC samples and cell lines, miR-301a-3p was significantly up-regulated compared with matched non-tumor tissues and normal pancreatic ductal cells, respectively. Overexpression of miR-301a-3p enhanced PDAC cells colony, invasion and migration abilities in vitro as well as tumorigenicity in vivo. Furthermore, SMAD4 was identified as a target gene of miR-301a-3p by cell as well as mice xenograft experiments. In PDAC tissue microarray, a significantly inverse correlation between miR-301a-3p ISH scores and SMAD4 IHC scores were observed in both tumor and corresponding non-tumor tissues.

CONCLUSIONS

MiR-301a-3p functions as a novel oncogene in PDAC and the oncogenic activity may involve its inhibition of the target gene SMAD4.

SMAD4 and its role in pancreatic cancer

Transforming growth factor-β (TGF-β) regulates cell functions and has key roles in pancreatic cancer development. SMAD4, as one of the Smads family of signal transducer from TGF-β, mediates pancreatic cell proliferation and apoptosis and is specifically inactivated in half of advanced pancreatic cancers. In recent years, many advances concerning SMAD4 had tried to unravel the complex signaling mechanisms of TGF-β and its dual role of tumor-suppressive and tumor-promoting efforts in pancreatic cancer initiation and progression through SMAD4-dependent TGF-β signaling and SMAD4-independent TGF-β signaling pathways. Meanwhile, its potential prognostic value based on immunohistochemical expression in surgical sample was variably reported by several studies and short of a systematic analysis. This review aimed to discuss the structure, functions, and regulation of this principal protein and its effects in determining the progression and prognosis of pancreatic cancer.

Prognostic significance of complications after laparoscopic colectomy for colon cancer

Aims

This study sought to evaluate the prognostic significance of postoperative complications for colon cancer patients undergoing laparoscopic surgery.

Methods

From May 2006 to May 2009, a total 224 patients who underwent laparoscopic curative resection (R0) for colon cancer were included in our retrospective study. Postoperative complications were evaluated according to a standardized grading system. The main outcome measurements of our study were overall survival (OS) and relapse-free survival (RFS), which were then compared between the no complication and complication groups. Univariate and multivariate analysis were used to assess the correlation between complications and prognosis.

Results

Fifty-nine postoperative complications occurred in 43 patients. The overall morbidity rate was 26.3%. The 5-year OS in the complication group was 41.4% compared with 78.5% in the no complication group (P<0.001). The cumulative incidence of relapse was also more aggressive in patients with complications (5-year RFS: complication group 40.9% vs. no complication group 82.1%, P<0.001). Multivariate analysis identified complications as a significant factor increasing the risk for both OS (RR 2.737; 95% CI 1.512–4.952; P = 0.001) and RFS (RR 4.247; 95% CI 2.291–7.876; P<0.001).

Conclusion

Postoperative complications could pose a significant adverse impact not only on OS but also on RFS in patients with colon cancer even when laparoscopic R0 resection is available.

Is laparoscopic colorectal cancer surgery associated with an increased risk in obese patients? A retrospective study from China

Background

The impact of obesity on surgical outcomes after laparoscopic colorectal cancer resection in Chinese patients is still unclear.

Methods

We retrospectively reviewed the prospectively collected data from 527 consecutive colorectal cancer patients who under went laparoscopic resection from January 2008 to September 2013. Patients were categorized into three groups: nonobese (body mass index (BMI) <25.0 kg/m²), obese I (BMI 25.0 = to 29.9 kg/m²) and obese II (BMI ≥30.0 kg/m²). Clinical characteristics, surgical outcomes and postoperative complications were compared between nonobese, obese I and obese II patients.

Results

From among the 527 patients, there were 371 patients with in the nonobese group, 142 patients in the obese I group and 14 patients in the obese II group. The patients were well-matched for age, sex and American Society of Anesthesiologists class, except for BMI (P = 0.001). The median operative time correlated highly significantly with increasing weight (median: nonobese = 135 minutes, obese I = 145 minutes, obese II = 162.5 minutes; P = 0.001). There appeared to be a slight tendency toward grade III complications (rated according to the Clavien-Dindo Classification of Surgical Complications) in the obese II group, but this difference was not significant (nonobese = 5.1%, obese I = 3.5% and obese II = 14.3%; P = 0.178). None of the grade III complications which occurred in the obese II group were wound dehiscences that required a stitch. Other aspects, such as estimated blood loss, harvested lymph nodes, operation type, pathological results, conversion rate and overall postoperative complications, were not statistically significant.

Conclusion

With sufficient experience, laparoscopic colorectal cancer surgery is feasible and safe in obese Chinese patients.

FBXL5 targets cortactin for ubiquitination-mediated destruction to regulate gastric cancer cell migration

Cortactin, an actin-interacting protein, is implicated in cytoskeletal architecture and often amplified in several types of cancer including gastric adenocarcinomas. Downregulation of cortactin decreases cell migration and invasion. However, how to regulate cortactin in gastric cancer remains largely unknown. Here, we report that FBXL5 interacts with and targets cortactin for ubiquitylation and subsequent proteasomal degradation. Furthermore, we showed that FBXL5-induced cortactin degradation is mediated by extracellular regulated signal kinase (ERK). Serine phosphorylation sites mutant, cortactinS405A/S418A, prevent FBXL5-induced cortactin degradation. Moreover, CortactinS405A/S418A exhibited stronger effects in promoting gastric cancer cell migration when compared to wild-type cortactin. Taken together, our data suggested a novel molecular mechanism for the negative regulation of cortactin by FBXL5 in gastric cancer cells migration.

Association between tumor necrosis factor-alpha 857C/T polymorphism and gastric cancer: a meta-analysis

Tumor necrosis factor-alpha (TNF-α) is an inflammatory cytokine which may play an important role on the immune response may control the progression of gastric cancer. Previous studies on the association between TNF-α 857C/T polymorphism and gastric cancer risk reported conflicting results. We performed a meta-analysis to comprehensively assess the association between TNF-α 857C/T polymorphism and gastric cancer risk. Literature search was performed for all publications on the association between TNF-α 857C/T polymorphism and gastric cancer risk through March 6, 2013. The pooled odds ratios (ORs) with their 95% confidence interval (95%CIs) were calculated to assess the association between TNF-α 857C/T polymorphism and gastric cancer risk. Nine individual case-control studies with a total of 5,054 subjects (1,835 cases and 3,219 controls) were finally included into the meta-analysis. Meta-analysis of total nine studies showed that TNF-α 857C/T polymorphism was significantly associated with increased risk of gastric cancer under four genetic models (for T vs. C: OR = 1.19, 95%CI 1.07-1.33, P = 0.002; for TT vs. CC: OR = 1.44, 95%CI 1.03-2.02, P = 0.032; for CT vs. CC: OR = 1.19, 95%CI 1.05-1.36, P = 0.008; and for TT/CT vs. CC: OR = 1.21, 95%CI 1.07-1.38, P = 0.003). Subgroup analysis by ethnicity further showed that there was a significant association between TNF-α 857C/T polymorphism and increased risk of gastric cancer in Asians but not in Caucasians. The meta-analysis suggests that TNF-α 857C/T polymorphism is significantly associated with increased risk of gastric cancer, especially in Asians.

Application of international videoconferences for continuing medical education programs related to laparoscopic surgery

BACKGROUND

Continuing medical education (CME) is an effective way for practicing physicians to acquire up-to-date clinical information.

MATERIALS AND METHODS

We conducted four CME seminars in 2007-2010 endorsed by the Chinese Medical Association Council on Medical Education. Overseas telelectures and live case demonstrations were introduced in each seminar via telemedicine based on a digital video transport system. Network stability and packet loss were recorded. An anonymous mini-questionnaire was conducted to evaluate the satisfaction of attendees regarding the image and sound quality, content selection, and overall evaluation.

RESULTS

Four telelectures and five live case demonstrations were successfully conducted. Stability of the network was maintained during each videoconference. High-quality videos of 720 × 480 pixels at the rate of 30 frames per second were shown to the entire group of attendees. The time delay between Shanghai and Fukuoka, Japan, was only 0.3 s, and the packet loss was 0%. We obtained 129 valid responses to the mini-questionnaire from a total of 146 attendees. The majority of the attendees were satisfied with the quality of transmitted images and voices and with the selected contents. The overall evaluation was ranked as excellent or good.

CONCLUSIONS

Videoconferences are excellent channels for CME programs associated with laparoscopic training.

Short-term and medium-term clinical outcomes of laparoscopic-assisted and open surgery for colorectal cancer: a single center retrospective case-control study

Background

Laparoscopic procedure is a rapid developed technique in colorectal surgery. In this investigation we aim at assessing the diversities of short-term and medium-term clinical outcomes of laparoscopic-assisted versus open surgery for colorectal cancer.

Methods

A total number of 519 patients with non-metastatic colorectal cancer were enrolled for this study. The patients underwent either laparoscopic-assisted surgery (LAP) (n = 254) or open surgery (OP) (n = 265). Surgical techniques, perioperative managements and clinical follow-ups were standardized. Short-term perioperative data and medium-term recurrence and survival were compared and analyzed between the two groups.

Results

There were no differences in perioperative parameters between the two groups except in regards to a trend of faster recovery in laparoscopic procedures. There was no statistically significant difference in postoperative complications, reoperation rate, or perioperative mortality. Statistically significant differences in a faster return of gastrointestinal function and shorter hospital stay were identified in favor of laparoscopic-assisted resection. In colon and rectal cancer cases separately, the overall survival, cancer-free survival and recurrence rate were similar in two groups. There was also no tendency of significant differences in overall survival, cancer-free survival and recurrence in stage I-II and stage III patients in two cancer categories between the two groups, respectively. pT, lymph node metastasis, and clinical stage were independent predictors of overall death risk, while pT, pN, lymph node metastasis and clinical stage were found to be the independent predictors of recurrence risk in enrolled patients database.

Conclusions

Laparoscopic-assisted procedure has more benefits on postoperative recovery, while has the same effects on medium-term recurrence and survival compared with open surgery in the treatment of non-metastatic colorectal cancer.

Clinical significance of expression of HIF-1α and EMT-related factors in pancreatic ductal adenocarcinoma

AIM: To investigate the expression of hypoxia inducible factor-1α (HIF-1α) and epithelial-mesenchvmal transition (EMT)-related factors in pancreatic ductal adenocarcinoma (PDAC) and to analyze their clinical significance.

METHODS: Immunohistochemistry was used to examine the expression of HIF-1α, Snail, Slug, E-cadherin and N-cadherin in 92 cases of PDAC and 10 cases of normal pancreatic tissue.

RESULTS: The positive expression rates of HIF-1α, Snail, Slug, E-cadherin and N-cadherin were 69.57%, 69.57%, 58.70%, 36.96% and 73.91% in PDAC, and 10%, 0%, 0%, 90% and 0% in normal pancreas tissue. HIF-1α expression was significantly associated with lymph node metastasis. Snail expression was correlated with TNM stage. Slug expression was positively associated with TNM stage and lymph node metastasis. N-cadherin expression was significantly related to TNM stage, lymph node metastasis and histological grade. HIF-1α expression in PDAC was positively correlated with Snail and Slug expression. There was a negative correlation between Snail and E-cadherin expression in PDAC. Expression of E-cadherin was negatively related to that of N-cadherin. Multivariate Cox analysis demonstrated that HIF-1α, Snail and E-cadherin were independent factors for prognosis of PDAC.

CONCLUSION: HIF-1α, Snail, Slug, E-cadherin and N-cadherin play significant roles in the progression and prognosis of PDAC.

Full counting statistics of level renormalization in electron transport through double quantum dots

We examine the full counting statistics of electron transport through double quantum dots coupled in series, with particular attention being paid to the unique features originating from level renormalization. It is clearly illustrated that the energy renormalization gives rise to a dynamic charge blockade mechanism, which eventually results in super-Poissonian noise. Coupling of the double dots to an external heat bath leads to dephasing and relaxation mechanisms, which are demonstrated to suppress the noise in a unique way.

Child-rearing attitudes and behavioral inhibition in Chinese and Canadian toddlers: a cross-cultural study

Behavioral inhibition data were collected from samples of 2-year-olds from the People's Republic of China and Canada. Information on child-rearing attitudes and beliefs was obtained from mothers of the children. Chinese toddlers were significantly more inhibited than their Canadian counterparts. Inhibition was associated positively with mothers' punishment orientation and negatively with mothers' acceptance and encouragement of achievement in the Canadian sample. However, the directions of the relations were opposite in the Chinese sample; child inhibition was associated positively with mothers' warm and accepting attitudes and negatively with rejection and punishment orientation. The results indicated different adaptational meanings of behavioral inhibition across cultures.

Child-rearing attitudes and behavioral inhibition in Chinese and Canadian toddlers: a cross-cultural study

Behavioral inhibition data were collected from samples of 2-year-olds from the People's Republic of China and Canada. Information on child-rearing attitudes and beliefs was obtained from mothers of the children. Chinese toddlers were significantly more inhibited than their Canadian counterparts. Inhibition was associated positively with mothers' punishment orientation and negatively with mothers' acceptance and encouragement of achievement in the Canadian sample. However, the directions of the relations were opposite in the Chinese sample; child inhibition was associated positively with mothers' warm and accepting attitudes and negatively with rejection and punishment orientation. The results indicated different adaptational meanings of behavioral inhibition across cultures.