MicroRNAs (miR) are single-stranded RNA of 21-23 nucleotides in length that repress mRNA translation and induces mRNA degradation. miR acts as an endogenous factor of gene expression and plays a crucial part in cancer biology such as cell development, proliferation, differentiation, and apoptosis. Numerous research has indicated that dysregulation of miR associates with colorectal carcinogenesis. In this review article, we firstly introduce the background of miR and colorectal cancer, and the mechanisms of miR in colorectal cancer, such as the proliferation, apoptosis, and progression. Then, we summarize the theranostic value of miR in colorectal cancer. Eventually, we discuss the potential directions and perspectives of miR. This article serves as a guide for further studies and implicate miR as a potent theranostic target for colorectal cancer.

Kaempferol is a kind of flavonoid, which has a significant anticancer effect. MMPs were discovered with the function of cleaving the extracellular matrix. We utilized bioinformatics to analyze the association and bonding mode between the traditional Chinese medicine (TCM) monomer composition (i.e., kaempferol) and the target proteins. The purpose of our research was to verify the effect of kaempferol on the biological behavior of human colon cancer cells HCT116 and HT29 and the expression of matrix metalloproteinase (MMP) 1, 2, and 9 genes. We detected the changes in the biological behavior of colon cancer cells treated with kaempferol by CCK-8, wound healing assay, transwell migration/invasion assay, and flow cytometry. Meanwhile， we detected the expression difference of the target gene by qRT-PCR and western blot. Compared with the two control groups, the cell viability of the kaempferol group decreased, the rate of cell migration and the number of transmembrane cells in the kaempferol group decreased significantly, and the early apoptosis rate increased, the number of cells in the G1 phase increased and in the S phase decreased. The results of qRT-PCR and western blot showed that the expression of target genes MMP1, 2, and 9 in the kaempferol group was lower than that in the two control groups. Kaempferol can significantly inhibit the proliferation, invasion, and migration ability of colon cancer cells; induce their apoptosis; and block the cell cycle. Meanwhile, the expression of MMP1, 2, and 9 genes was downregulated, which verified the results of bioinformatic analysis.

Objective. To investigate the effect of Runt‐associated transcription factor 3 (RUNX3) on the invasion and metastasis of human colon cancer HT‐29 cells and to preliminarily explore the mechanism of its anticancer effect. Methods. The RUNX3 plasmid vector was transfected into human colon cancer HT‐29 cells by liposome‐mediated transfection, while the empty vector and the blank group were used as the control group. After Geneticin (G418) screening, HT‐29 cells with stable expression of RUNX3 gene were obtained. The expressions of mRNA and proteins of RUNX3 and metalloproteinases (MMP)‐2/9 were detected by reverse transcription‐polymerase chain reaction (RT‐PCR) and western blot. Cell proliferation was determined by MTT assay. The effect of RUNX3 on invasion and metastasis of HT‐29 cells was evaluated by scratch injury assay, Transwell chamber, and Matrigel invasion model. Results. RUNX3 was expressed stably in HT‐29 cells after transfection. The expressions of RUNX3 mRNA and proteins in the experimental group were significantly higher than those in the blank/empty vector groups. Meanwhile, the expressions of MMP‐2/9 mRNA and proteins in the observation group were significantly lower than those in the blank group and the empty vector group. The proliferation and migration ability in the experimental group was significantly lower than blank/empty vector groups from the third day. Transwell chamber experiment and Matrigel invasion assay showed that the number of Transwell cells was decreased significantly than blank/empty vector groups, but no difference was found between the blank group and the empty vector group. Conclusion. RUNX3 can inhibit the invasion and metastasis of human colon cancer HT‐29 cells, and the mechanism may be related to decreased expression of MMP‐2 and MMP‐9.

Background: Indirect inguinal hernia and sigmoid colon cancer are both common diseases, but carcinoma within the hernia sac is rare. We present a case of sigmoid colon cancer masquerading as a right incarcerated inguinal hernia. Since such a presentation is rare, and the correct diagnosis is usually made intraoperatively, there is still no consensus on the best treatment modality for such patients. Case Presentation: A 70-year-old man presented to our hospital on September 20, 2020, with a right inguinal mass that had been painful for half a month, accompanied by symptoms of difficult defecation. The bulge was originally found at least 60 years before admission. There was no pain at the time; however, the mass enlarged progressively during the last 3 years. The right scrotum and groin area were obviously enlarged (~20 × 20 cm) and tender. Inside the scrotum, a circumscribed medium-hard mass (diameter 5 cm) that was palpable, with ill-defined borders and translational mobility was detected. The computed tomography (CT) scan showed a right blood vessel-containing strangulated inguinal hernia; the sigmoid colon showed focal wall thickening as it was in proximity to the inguinal hernia. Based on the biopsy results, a pathologic diagnosis of high-grade intraepithelial neoplasia was made. The preliminary diagnosis was that of sigmoid carcinoma and right incarcerated inguinal hernia. Emergency laparoscopic exploration, open sigmoid radical resection andright inguinal hernia repair were performed under general anesthesia. The patient recovered successfully and was discharged 1 week after the operation. One month after surgery, no discomfort and signs of recurrence were found. Conclusions: The combination of colorectal cancer and inguinal hernia is uncommon, and detailed preoperative physical examination and imaging studies may contribute to the establishment of a correct diagnosis. The selection of appropriate surgical methods ensures good therapeutic results.

Background: LncRNA cancer susceptibility candidate 9 (CASC9) is up-regulated in various cancers. In this study, we explored the role of CASC9 in colon cancer (CC). Methods: The level of CASC9 in CC tissues, adjacent normal tissues, intestinal epithelial cells (HIEC) and CC cell lines was evaluated by qRT-PCR. HCT116 and SW480 CC cells were transfected with siCASC9. The cell growth and cell proliferation makers (Ki-67 and PCNA) were detected by CCK-8, colony formation and western blotting, respectively. The cell apoptosis and cell cycle were determined by flow cytometry. MicroRNA sponged by CASC9 was predicted by starBase and verified by dual-luciferase reporter assay. Further analyses were performed to investigate the role of CASC9 sponging the microRNA in CC cells by transfection or co-transfection of siCASC9 and miR-145-5p inhibitor. Results: LncRNA CASC9 was high-expressed in CC cells and tissues, especially in CC at advanced TNM stages. In HCT116 and SW480 cells, knockdown of CASC9 suppressed cell proliferation, promoted cell apoptosis and arrested cell cycle at G0/G1 phase. Furthermore, CASC9 was observed to sponge and regulate the expression of miR-145-5p, which was down-regulated in CC tissues. Moreover, increased cell proliferation and decreased cell apoptosis and arrested cell cycle caused by miR-145-5p inhibitor were abrogated by the knockdown of CASC9. Conclusions: LncRNA CASC9 is an oncogene in CC cells through sponging miR-145-5p. The findings in the current study provide a new understanding on CASC9 in CC.

To investigate the specificity of Target of Myb1-Like1 (Tom1L1) expression in colorectal adenocarcinoma tissues and analyze the predictive value of Tom1L1 in the efficacy of neoadjuvant chemotherapy for patients with rectal adenocarcinoma. The cancerous tissues and paracancerous normal tissues of 102 patients diagnosed with colorectal adenocarcinoma without treatment were selected; quantitative polymerase chain reaction (qPCR), Western blot and immunohistochemistry (IHC) were adopted to validate the expression level of Tom1L1 in the two groups. Furthermore, 34 patients with locally progressive mid-low rectal adenocarcinoma, who were treated with neoadjuvant Xelox chemotherapy prior to the operation, IHC was adopted to detect the expression of Tom1L1 protein in patients before and after neoadjuvant chemotherapy and to analyze the relationship between the expression level of Tom1L1 and the sensitivity of neoadjuvant therapy. The results of qPCR, Western blot and IHC showed that the expression of Tom1L1 in colorectal adenocarcinoma tissues was significantly higher than that in paracancerous normal tissues, with a statistically significant difference (P < 0.01); Neoadjuvant chemotherapy was significantly more effective in patients with low expression of Tom1L1 protein than in those with high expression of Tom1L1 protein, with a statistically significant difference (P < 0.05). Tom1L1 is highly expressed in colorectal adenocarcinoma tissues; neoadjuvant Xelox chemotherapy can have an impact on Tom1L1 expression in progressive rectal cancer; patients with locally progressive mid-low rectal adenocarcinoma who have low Tom1L1 expression are more sensitive to neoadjuvant chemotherapy.