Colorectal cancer (CRC) is the third most common malignancy and the third leading cause of cancer related deaths in the United States. Almost 90% of the patients diagnosed with CRC die due to metastases. MicroRNAs (miRNAs) are evolutionarily conserved molecules that modulate the expression of their target genes post-transcriptionally, and they may participate in various physiological and pathological processes including CRC metastasis by influencing various factors in the human body. Recently, the role miRNAs play throughout the CRC metastatic cascade has gain attention. Many studies have been published to link them with CRC metastasis. In this review, we will briefly discuss metastatic steps in the light of miRNAs, along with their target genes. We will discuss how the aberration in the expression of miRNAs leads to the formation of CRC by effecting the regulation of their target genes. As miRNAs are being exploited for diagnosis, prognosis, and monitoring of cancer and other diseases, their high tissue specificity and critical role in oncogenesis make them new biomarkers for the diagnosis and classification of cancer as well as for predicting patients' outcome. MiRNA signatures have been identified for many human tumors including CRC, and miRNA-based therapies to treat cancer have been emphasized lately. These will also be discussed in this review.

d MicroRNAs (miRNAs) are dysregulated in many types of malignant diseases, including colorectal cancer. miRNA 30a (miR-30a) is a member of the miR-30 family and has been implicated in many types of cancers. In this study, we determined the expression of miR-30a in human colon cancer tissues and cell lines. miR-30a was found to be significantly downregulated in both the tissues and cell lines. Furthermore, overexpression of miR-30a inhibited, while silencing of miR-30a promoted, cell proliferation, migration, and invasion in vitro. Consistently, stable overexpression of miR-30a suppressed the growth of colon cancer cell xenografts in vivo. Moreover, bioinformatic algorithms and luciferase reporter assays revealed that insulin receptor substrate 2 (IRS2) is a direct target of miR-30a. Further functional studies suggested that repression of IRS2 by miR-30a partially mediated the tumor suppressor effect of miR-30a. In addition, miR-30a inhibited constitutive phosphorylation of Akt by targeting IRS2. Additionally, clinicopathological analysis indicated that miR-30a has an inverse correlation with the staging in patients with colon cancer. Taken together, our study provides the first evidence that miR-30a suppressed colon cancer cell growth through inhibition of IRS2. Thus, miR-30a might serve as a promising therapeutic strategy for colon cancer treatment. Colorectal cancer (CRC) is the third most common cancer in males and females, with an estimated 142,820 new cases and 50,830 deaths in the United States in 2013. The overall CRC incidence is 5% in the general population, and the 5-year survival rate ranges from 40% to 60% (1). Despite the improvement of currently available treatment strategies, including surgical resection, radiotherapy, and chemotherapy, the survival rate of patients with CRC has changed little over the past 10 years. Almost 50% of CRC patients will die of the disease, mainly due to metastasis to the liver. Thus, it is imperative to achieve earlier diagnosis and better tailoring of treatments to improve CRC outcomes.MicroRNAs (miRNAs) are a family of endogenous small noncoding RNAs that regulate gene expression via the sequence-specific base pairing on the 3= untranslated regions (3= UTRs) of target mRNAs, resulting in mRNA cleavage or translation inhibition (2). More than 30% of the protein-coding genes are controlled by miRNAs, as indicated by bioinformatics predictions. miRNAs are involved in a plethora of biological processes, such as proliferation, migration, invasion, and apoptosis (3, 4). In recent years, miRNAs have been recognized as critical regulators in development and progression of cancer, including CRC (5-8).miRNA 30a (miR-30a) is a member of the miR-30 family, which consists of six distinct mature miRNA sequences: miR-30a/ miR-30c-2, miR-30d/miR-30b, and miR-30e/miR-30c-1 (9). There is considerable evidence suggesting that the dysregulation of miR-30a is correlated with several types of malignant tumors, including breast cancer, lung cancer, thyroid cancer, gastric cancer, and leuke...

Although somatic alterations in CAG repeats in the androgen receptor (AR) gene have been suggested to predispose to colorectal cancer, less is known about AR in colorectal cancer carcinogenesis. Because of lack of relevant analysis on CAG repeat length and AR expression in colorectal cancer, we aimed to investigate the prognostic value of polymorphic CAG and protein expression of the AR gene in patients with colorectal cancer. A case-control study was carried out on 550 patients with colorectal cancer and 540 healthy controls to investigate whether polymorphic CAG within the AR gene is linked to increased risk for colorectal cancer. Polymorphic CAG and AR expression were analyzed to clarify their relationship with clinicopathologic and prognostic factors in patients with colorectal cancer. The study showed that the AR gene in patients with colorectal cancer had a longer CAG repeat sequence than those in the control group, as well as increased risk for colorectal cancer among females (P ¼ 0.013), males (P ¼ 0.002), and total colorectal cancer population (P < 0.001), respectively. AR expression exhibited a significant difference in long CAG repeat sequence among males (P < 0.001), females (P < 0.001), and total colorectal cancer study population (P < 0.001). Both long CAG repeat sequence and negative AR expression were associated with a short 5-year overall survival (OS) rate in colorectal cancer. Long CAG repeat sequences and the absence of AR expression were closely related to the development of colorectal cancer. Both long CAG and decreased AR expression were correlated with the poor 5-year OS in patients with colorectal cancer.

BackgroundThe purpose of this study was to compare short-term clinical outcomes of ileocolonic functional end-to-end anastomosis (FEEA) and end-to-side anastomosis (ESA) following resection of the right colon for cancer.MethodsWe enrolled 379 patients who underwent ileocolonic anastomosis following resection of the right colon for cancer by a single surgeon, from January 2009 through June 2012. Patient characteristics, operative results, and postoperative complications were analyzed.ResultsA total of 164 patients received ESA and 215 patients received FEEA. The FEEA group had a lower incidence of anastomotic error (0.9% versus 4.3%; P = 0.04) and a shorter operating time (140.4 ± 14.9 min versus 150.5 ± 20.1 min; P = 0.001). The length of hospital stay (10.9 ± 3.5 days versus 11.3 ± 4.0 days; P = 0.36) and anastomotic leakage (1.8% versus 0.5%; P = 0.20) were similar in both groups. No relevant differences between FEEA and ESA were observed for blood loss, retrieved lymph nodes, first flatus and postoperative complications.ConclusionAn FEEA after right hemicolectomy for colon cancer is a safe and reliable anastomotic technique, resulting in a favorable outcome in selected patients with the right colon cancer.