The genetics and molecular biology of colonic neoplasia: practical implications for the clinician

Overexpression of gene DEP domain containing 1 and its clinical prognostic significance in colorectal cancer

Background

Colorectal cancer (CRC) is one of the most commonly seen malignancies worldwide, yet its regulatory mechanisms still need to be further illuminated. Abundant evidence revealed that aberrant expression of cancer‐related genes contributes to CRC progression. DEP domain containing 1 (DEPDC1) has been found to play a crucial role in the carcinogenesis and development of malignancies. Nevertheless, limited studies have been concerned with the role of DEPDC1 in CRC. This study aimed to investigate the relationship between DEPDC1 expression and CRC clinicopathological parameters.

Methods

Solid CRC tissues and adjacent noncancerous tissues (ANCTs) (n = 150) were chosen randomly to detect the mRNA expression levels of DEPDC1 by real‐time quantitative reverse transcription‐polymerase chain reaction (RT‐qPCR). Formalin‐fixed, paraffin‐embedded (FFPE) blocks of CRC tissues and ANCTs (n = 150) were acquired to examine DEPDC1 protein expression levels by immunohistochemistry (IHC).

Results

DEPDC1 was significantly overexpressed in CRC tissues than that in ANCTs (P < .05). High protein expression of DEPDC1 was associated with poorer TNM stage and recurrence (P < .001 and P = .003, respectively). Kaplan‐Meier survival analysis showed significantly shorter overall survival (OS) and disease‐free survival (DFS) in DEPDC1 protein high‐expression group compared with low‐expression group (P < .05). Univariate analysis demonstrated that DEPDC1 protein expression was correlated with DFS (P = .005) and OS (P = .006). Multivariate analysis revealed that the combination of DEPDC1 protein expression and TNM stage has statistical significance in CRC prognosis prediction (P = .024 and P = .009, respectively).

Conclusions

DEPDC1 may act as a potential biomarker for CRC detection as well as a prognostic predictor concerning the survival of CRC patients.

LEPR polymorphisms and haplotypes in Mexican patients with colorectal cancer

INTRODUCTION

Obesity and colorectal cancer could be linked by adipocytokines, which are proteins associated with cell proliferation. High levels of the adipocytokine leptin promote the development of colorectal cancer through its receptor.

OBJECTIVE

To determine the association between c.326A>G and c.668A>G LEPR gene polymorphisms and colorectal cancer.

MATERIALS AND METHODS

DNA was extracted from the peripheral blood of 147 patients with sporadic colorectal cancer and 134 healthy people. Genotypes were obtained by PCRRFLP and the association was determined by the odds ratio (OR) test using the SPSS™, version 10.0, program. Haplotype frequencies and linkage disequilibrium were estimated by the Arlequin, version 3.5, software.

RESULTS

Both polymorphisms were in Hardy-Weinberg equilibrium. Only the c.326A>G heterozygous genotype revealed an increased risk for colorectal cancer development (OR=1.81, 95% CI=1.04-3.16, p=0.04). The AG haplotype showed a significant association with colorectal cancer (OR=0.58, 95% CI=0.35-0.96, p<0.03). Linkage disequilibrium between the variants was only evident for the patients group (r2=0.36).

CONCLUSION

Our results suggest that AG individuals heterozygous for the c.326A>G LEPR variant have a higher risk of colorectal cancer development whereas the AG haplotype (c.326A/c.668G) has a protective effect in the Mexican population.