Identification of microRNA 885-5p as a novel regulator of tumor metastasis by targeting CPEB2 in colorectal cancer.

Colorectal cancer is the third most common cancer in the world and liver is the most frequent site of distant metastasis with poor prognosis. The aim of this study is to investigate microRNAs leading to liver metastasis. We applied microarray analysis and quantitative PCR to identify and validate dysregulated miRNAs in liver metastases when compared to primary CRCs. Functional significance and the underlying molecular mechanism of selected miRNA was demonstrated by a series of in vitro and in vivo assays. Our microarray analysis and subsequent quantitative PCR validation revealed that miR-885-5p was strongly up-regulated in liver metastases and in CRC cell-lines derived from distant metastases. Overexpression of miR-885-5p significantly induced cell migration, cell invasion, formation of stress fibre in vitro and development of liver and lung metastases in vivo. MiR-885-5p induced metastatic potential of CRC by repressing cytoplasmic polyadenylation element binding protein 2 transcription through directly binding to two binding sites on its 3' untranslated region, and consequently led to up-regulation of TWIST1 and hence epithelial-mesenchymal transition. Our findings demonstrated the overexpression of miR-885-5p in liver metastasis and its roles in inducing CRC metastasis, potentiating development of miR-885-5p inhibitor to treat advanced CRC in the future.

Identification of serum miR-139-3p as a non-invasive biomarker for colorectal cancer.

Aberrant levels of circulating microRNAs are potential biomarkers for the early detection of colorectal cancer. The aim of this study was to study miR-139-3p and miR-622 in serum as a non-invasive biomarker for colorectal cancer diagnosis. We applied quantitative polymerase chain reaction to determine the levels of miR-139-3p and miR-622 in 42 pairs of tumor and adjacent non-tumor tissues, and in serum samples of 117 patients and 90 control subjects. Our results showed that miR-139-3p was silenced whereas miR-622 was overexpressed in colorectal cancer. Similarly, serum miR-139-3p level was significantly lower in colorectal cancer patients than in control subjects whereas miR-622 was more frequently detectable in patients. ROC analysis showed that AUC of miR-139-3p was 0.9935, with a sensitivity of 96.6% and specificity of 97.8%. Serum miR-139-3p level showed high sensitivity and specificity for both early and late stage CRCs and proximal and distal CRCs. Detectable serum miR-622 showed a sensitivity of 87.5% and specificity of 63.5% for discriminating CRC patients, but the sensitivity dropped for late stage patients (72.7%). We also included analyses of the blood CEA level for comparing the diagnostic performance of these blood-based biomarkers. The median level in CRC patients (3.6 ng/ml) was significantly higher than that in control (1.8 ng/ml). The AUC value of CEA in diagnosing CRC patients was 0.7515. CEA showed a positive correlation with tumor stage and age of patients and its level was higher in male. Collectively, serum miR-139-3p has strong potential as a promising non-invasive biomarker in colorectal cancer detection.

Laparoscopic colorectal resections with and without routine mechanical bowel preparation: A comparative study.

BACKGROUND: The benefit of mechanical bowel preparation (MBP) in patients undergoing laparoscopic colorectal resections remains a question. This study aimed to evaluate the effect of omitting MBP on patients undergoing laparoscopic bowel resections. METHODS: The outcomes of patients who underwent elective colorectal resections for cancer of colon and upper rectum without MBP were compared to a retrospective cohort who had MBP. RESULTS: There were 97 patients in the No-MBP group and 159 patients in the MBP group. Their mean age, operative risk, tumor size and stage of disease were similar. There were no significant differences in operative time and estimated blood loss. The anastomotic leakage rate was 1.0% in the No-MBP group and 0.6% in the MBP group, (p = 1.00). Wound infection rate were 4.1% and 3.8% in the No-MBP group and the MBP group respectively (p = 1.00). Overall surgical morbidity rate was 11.3% in the No-MBP group and 8.2% in the MBP group (p = 0.40). Conversion rates were 5.2% in the No-MBP group and 6.9% in the MBP group, (p = 0.57). CONCLUSION: The omission of mechanical bowel preparation does not increase surgical morbidities in patients undergoing laparoscopic bowel resections. It also has no effect on operating time and conversion rate.

Osteopontin Overexpression Induced Tumor Progression and Chemoresistance to Oxaliplatin through Induction of Stem-Like Properties in Human Colorectal Cancer.

Colorectal cancer (CRC) is one of the most common and fatal malignancies worldwide. The poor prognosis of colorectal cancer patients is due to development of chemoresistance and cancer metastasis. Recently osteopontin (OPN) has been associated with stem-like properties in colorectal cancer. This study further examined the clinicopathological significance of OPN in CRC and its effect on chemoresistance and transcription of stem cell markers. We examined the transcription level of OPN in 84 CRC patients and correlated the expression with their clinicopathological parameters. The associations of OPN overexpression with transcription of stem cell markers and response to chemotherapy in DLD1-OPN overexpressing clones and CRC patients were also investigated. Our results showed that OPN was significantly overexpressed in CRC, and its overexpression correlated with tumor stage and poor prognosis. Overexpression of CRC induced OCT4 and SOX2 expression in vitro and correlated with SOX2 overexpression in CRC patients. In addition, DLD1-OPN overexpressing cells showed enhanced ability to survive upon oxaliplatin treatment, and OPN expression was higher in CRC patients who were resistant to oxaliplatin-involved chemotherapy treatment. Thus, CRC cells overexpressing OPN demonstrated stem-like properties and OPN inhibition is a potential therapeutic approach to combat CRC progression and chemoresistance.

Post-operative plasma osteopontin predicts distant metastasis in human colorectal cancer.

BACKGROUND: The overall prognosis of colorectal cancer (CRC) patients is unsatisfactory due to cancer metastasis after operation. This study aims to investigate the clinical significance of plasma osteopontin (OPN) levels as minimally invasive, predictive, and surrogate biomarkers for prognosis of CRC patients. METHODS: This randomized study design consists of pre-operative and post-operative plasma samples from a total of 79 patients. We determined plasma levels of OPN by ELISA and examined their correlation with the clinicopathological parameters of CRC patients. The effects of endogenous and exogenous OPN on CRC metastasis were investigated by examination of the effect on regulators of epithelial to messenchymal transition and migration assay. RESULTS: Our findings demonstrated for the first time the clinical correlation of plasma OPN with metastasis of CRC patients. High post-operative plasma OPN level (>153.02 ng/ml) associated with development of metastasis after curative resection (p<0.001). Moreover, post-operative plasma OPN level correlated with disease-free survival of CRC patients (p=0.009) and was an independent factor for predicting development of metastasis in CRC patients after curative resection (p=0.036). Our in vitro model showed that OPN ectopic expression induced DLD1 cell migration through Snail and Twist1 overexpression and E-cadherin repression, and secretory OPN level enhanced cell migration. CONCLUSIONS: The results of the current study suggest that post-operative plasma OPN correlated with post-operative metastasis, suggesting that it is a potential non-invasive biomarker for the development of future metastasis in CRC patients. In addition, OPN was shown to be involved in the metastatic process and thus inhibition of OPN is a potential therapeutic approach to treat CRC patients.

The clinicopathological significance of miR-133a in colorectal cancer.

This study determined the expression of microRNA-133a (MiR-133a) in colorectal cancer (CRC) and adjacent normal mucosa samples and evaluated its clinicopathological role in CRC. The expression of miR-133a in 125 pairs of tissue samples was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and correlated with patient's clinicopathological data by statistical analysis. Endogenous expression levels of several potential target genes were determined by qRT-PCR and correlated using Pearson's method. MiR-133a was downregulated in 83.2% of tumors compared to normal mucosal tissue. Higher miR-133a expression in tumor tissues was associated with development of distant metastasis, advanced Dukes and TNM staging, and poor survival. The unfavorable prognosis of higher miR-133a expression was accompanied by dysregulation of potential miR-133a target genes, LIM and SH3 domain protein 1 (LASP1), Caveolin-1 (CAV1), and Fascin-1 (FSCN1). LASP1 was found to possess a negative correlation (γ = -0.23), whereas CAV1 exhibited a significant positive correlation (γ = 0.27), and a stronger correlation was found in patients who developed distant metastases (γ = 0.42). In addition, a negative correlation of FSCN1 was only found in nonmetastatic patients. In conclusion, miR-133a was downregulated in CRC tissues, but its higher expression correlated with adverse clinical characteristics and poor prognosis.

Plasma Bmi1 mRNA as a potential prognostic biomarker for distant metastasis in colorectal cancer patients.

Bmi1 is overexpressed in gastrointestinal cancers, including colorectal cancer (CRC); however, its role as a non-invasive biomarker in CRC has not been established. The aim of this study was to compare the plasma Bmi1 mRNA levels prior to and following curative resection of the primary tumor in CRC patients and to determine their association with the clinicopathological parameters. The plasma Bmi1 mRNA level was measured by quantitative polymerase chain reaction and expressed as cycle threshold value. There was no significant difference between the overall pre- and postoperative plasma Bmi1 mRNA level (31.73±2.63 vs. 31.93±2.88, respectively; P=0.614) in 45 CRC patients. However, when grouped into non-metastatic and metastatic CRC patients, the postoperative Bmi1 transcript level was found to be significantly lower compared to the preoperative level in patients with non-metastatic CRC (32.13±2.677 31.44±2.764, respectively; P=0.041), whereas there was a trend towards a higher postoperative Bmi1 transcript level compared to the preoperative level in the metastatic counterpart (30.85±3.916 vs. 33.27±0.718, respectively; P=0.164). Furthermore, when the patients were categorized into two groups according to their plasma Bmi1 postoperative vs. preoperative level status, we observed that patients without a reduction in the postoperative plasma Bmi1 mRNA levels exhibited a significantly higher rate of distant metastasis following primary resection (P=0.017) and a significantly worse prognosis regarding disease-free survival (P=0.016) when compared to the reduced postoperative plasma Bmi1 level counterparts. In conclusion, plasma Bmi1 mRNA levels may serve as a non-invasive biomarker for monitoring occult metastasis and predicting the development of distant metastasis.

Health-related quality of life and risk of colorectal cancer recurrence and All-cause death among advanced stages of colorectal cancer 1-year after diagnosis.

BACKGROUND: The study aimed to examine the association between health-related quality of life (HRQOL) assessed with overall survival (OS) and recurrence after diagnosis of colorectal cancer (CRC). METHODS: Overall 160 patients with advanced stage CRC were recruited in an observational study and completed the generic and condition-specific HRQOL questionnaires at the colorectal specialist outpatient clinic in Hong Kong, between 10/2009 and 07/2010. Socio-demographic and clinical characteristics including duration since diagnosis, primary tumor location and treatment modality, were collected to serve as predictor variables in regression models. All-cause death or CRC recurrence was the event of interest. Association between HRQOL with OS was assessed using Cox regression. Association between HRQOL and CRC recurrence was further modeled by competing-risks regression adjusted for the competing-risks of death from any cause. RESULTS: After a median follow-up of 23 months, there were 22 (16.1%) incidents of CRC recurrence and 15 (9.4%) deaths. Decreased physical functioning (hazard ratios, HR = 0.917, 95% CI:0.889-0.981) and general health of domains in SF-12 (HR = 0.846, 95% CI:0.746-0.958) or SF-6D scores (HR = 0.010, 95% CI:0.000-0.573) were associated with an increased risk of death, with adjustment of patients' characteristics. Increased vitality (HR = 1.151, 95% CI:1.027-1.289) and mental health (HR = 1.128, 95% CI:1.005-1.265) were associated with an increased likelihood of death. In models adjusted for competing-risk of death, those with worse HRQOL was not associated with increased risk of CRC recurrence. CONCLUSIONS: Although self-reported HRQOL was not a significant prognostic factor for CRC recurrence, the HRQOL provided independent prognostic value about mortality in patients with advanced stage of CRC.

Prognostic significance of CD26 in patients with colorectal cancer.

BACKGROUND: CD26, dipeptidyl peptidase IV, was discovered firstly as a membrane-associated peptidase on the surface of leukocyte. We previously demonstrated that a subpopulation of CD26+ cells were associated with the development of distant metastasis, enhanced invasiveness and chemoresistance in colorectal cancer (CRC). In order to understand the clinical impact of CD26, the expression was investigated in CRC patient's specimens. This study investigated the prognostic significance of tumour CD26 expression in patients with CRC. Examination of CD26+ cells has significant clinical impact for the prediction of distant metastasis development in colorectal cancer, and could be used as a selection criterion for further therapy. METHODS: Tumour CD26 expression levels were studied by immunohistochemistry using Formalin-fixed paraffin embedded (FFPE) tissues in 143 patients with CRC. Tumour CD26 expression levels were correlated with clinicopathological features of the CRC patients. The prognostic significance of tumour tissue CD26 expression levels was assessed by univariate and multivariate analyses. RESULT: CD26 expression levels in CRC patients with distant metastasis were significantly higher than those in non-metastatic. High expression levels of CD26 were significantly associated with advanced tumour staging. Patients with a high CD26 expression level had significantly worse overall survival than those with a lower level (p<0.001). CONCLUSIONS: The expression of CD26 was positively associated with clinicopathological correlation such as TNM staging, degree of differentiation and development of metastasis. A high CD26 expression level is a predictor of poor outcome after resection of CRC. CD26 may be a useful prognostic marker in patients with CRC.

Incarceration of a colonoscope in an inguinal hernia: Case report and literature review.

Incarceration of an endoscope in an inguinal hernia may occur during the course of routine colonoscopy. The incarceration may occur on insertion or withdrawal and frequently the hernia is not suspected prior to the colonoscopy. Most commonly, a left sided inguinal hernia is involved, however right inguinal hernias may be implicated in subjects with altered anatomy post abdominal surgery. Incarceration of an endoscope in an inguinal hernia has been seldom reported in the literature which is likely to be related to under reporting. A range of techniques have been suggested by various authors over the last four decades to manage this unusual complication of colonoscopy. These techniques include utilizing fluoroscopy, manual external pressure and/or the fitting of a cap onto the tip of the colonoscope to facilitate colonoscopic navigation. The authors present a case report of incarceration of the colonoscope on withdrawal in an unsuspected left inguinal hernia with a review of the literature on the management of this colonoscopic complication. A management strategy is suggested.

Outcome of laparoscopic colectomy for cancer in elderly patients.

BACKGROUND: Resection for colon cancer in the elderly is a major undertaking. However, data on the outcome and survival of elderly patients who underwent laparoscopic resection for colon cancer are limited. This study of patients older than 75 years compared outcome and survival between those who underwent laparoscopic resection and those who had open resection for colorectal cancer. METHODS: From 2000 to 2009, 434 patients ages 75 years and older who underwent elective resection for colon cancer were included in the study. Patients who had rectal cancer or had undergone emergency operations were excluded. Preoperative diagnosis was determined by colonoscopy, and computed tomography scan was performed for preoperative staging. Data on the patients' demographics, operative details, pathology results, postoperative results, and survival were collected prospectively. The patients who underwent laparoscopic surgery were compared with those who had open surgery. RESULTS: The study included 434 patients (210 men) with a median age of 80 years (range 75-95 years). Of these 434 patients, 189 underwent laparoscopic resection. Nine patients (4.8%) required conversion to open operation. The patients did not differ in terms of age, gender, incidence of medical comorbidities, or stage of disease. The median operating time was longer in the laparoscopic group, but the blood loss was significantly less. Laparoscopic resection was associated with a lower mortality rate and a shorter hospital stay (p < 0.05). The open resection group had significantly more cardiac complications (p < 0.05). The overall 5-year survival rates were similar between the patients who had laparoscopic resections and those who had open surgery. CONCLUSIONS: For patients older than 75 years, laparoscopic resection of colon is associated with less intraoperative blood loss, a shorter hospital stay, fewer cardiac complication, and a lower mortality rate than open resection. Therefore, the authors recommend laparoscopic resection of colon cancer as the treatment of choice for elderly patients.

Needlescopic totally extraperitoneal hernioplasty for unilateral inguinal hernia in adult patients.

OBJECTIVE: Totally extraperitoneal (TEP) inguinal hernioplasty for inguinal hernia is associated with less postoperative pain, shorter hospital stays, less chronic pain, and increased patient satisfaction when compared with the open Lichtenstein approach‥ However, only few studies to date have compared conventional with needlescopic TEP hernioplasty for treating unilateral inguinal hernias in adult patients. We report our prospective study that compared the postoperative outcomes of these two approaches over a 2-year period. METHODS: From July 2007 to June 2009, a total of 32 patients underwent attempted unilateral needlescopic TEP hernioplasty. All data were prospectively collected and analysed, including demographic features, types of hernia, and postoperative outcome. The results were compared with those of an agematched cohort of 32 patients who underwent conventional TEP hernioplasty in the same period. RESULTS: Needlescopic TEP hernioplasty was successfully performed in 24 patients. The other eight procedures were completed with conventional TEP approaches after changing one or two 5-mm ports. The most common hernia type was Nyhus type III (38/64, 59.3%). There was no significant difference in the mean operative time, hospital stay, and postoperative pain scores between the needlescopic and conventional approaches. There was no major complication detected on the first visit, except seroma formation (9 patients in the needlescopic group and 11 in the conventional group), all of which was resolved with conservative management. No recurrence of hernia was noted in either group during the mean follow-up period of 88.0 weeks. CONCLUSION: Needlescopic TEP hernioplasty was a feasible technique in selected patients for inguinal hernia repair. Postoperative recovery following both approaches was similar. However, because this was a small cohort study, larger prospective, randomized controlled trials are required to establish the longterm benefit, safety and complications of needlescopic surgery.

Pyeloduodenocolic fistula.

A 75-year-old man presented with epigastric pain and melaena. Multiple right renal stones were seen on abdominal X-ray. Computed tomography of the abdomen and oesophagogastroduodenoscopy revealed features of a pyeloduodenal fistula. Elective surgery was planned but the patient developed torrential bleeding with shock. Emergency laparotomy revealed a necrotic right kidney with a pyeloduodenocolic fistula. This report is the first of a pyeloduodenocolic fistula caused by squamous cell carcinoma of the renal pelvis. We review the literature and discuss the aetiologies, clinical presentations, diagnosis, and treatment of pyeloduodenal fistula.