Personalized treatment is better than one treatment fits all in the management of patients with mCRC: a consensus statement

To Assess the Role of microRNA-451 in the Progression and Metastasis of Colorectal Cancer

The study aimed to determine the expression of miR451 in colorectal cancer (CRC) subjects with CRC cells, and the role of miR451 in colorectal cancer cells. In October 2020, ATC purchased CRC and normal mucosal cell lines of CRC and implanted them in DMEM with 10% fetal serum. The suitability of the HT29 cell line is verified using the STR profile. In an incubator with 5% CO2, enlarged cells were placed at 37 °C. TCGA data was used to select the top 120 patients with a high voice and the lowest 120 patients with a low voice. Cells were collected and coated with Annexin V and PE according to the manufacturer's instructions after 24.0 h. After that, the cells were separated. Cells were also tested using flow cytometry. HCT-120 cells were transplanted into a concentration of 5×105/ml cells in 6-source plates. HCT120 cells in the experimental group were combined with miR451 mimics, miR451 inhibitors, or miR451 miR + SMAD4B for 12 h at 37 °C, and cells were collected 24 h later at 37 °C. The sample was injected with 5 ml of Annexin VFITC and PE. Compared with normal colorectal mucosal cells, CRC cell lines decreased miR451 expression levels (fetal human cells (FHC) and HCoEpiC). Then, the HCT120 cells were transfected with miR451 inhibitors, and 72 h after transfection, say of miR451 was normal. There was a significant decrease in cell function in the miR451mimic groups, but an increase when the miR451 was blocked. The proliferation of cancer cells was prevented and chemotherapy was effective when miR451 was overexpressed. The SMAD4 gene provides instructions for making a protein involved in transmitting chemical signals from the cell surface to the nucleus. The SMAD4B expression was tested by RT-qPCR and Western blotting after 72.0 h of transmission. The mRNA and protein expression of SMAD4B decreased significantly when miR451 was significantly higher than when inhibited, as revealed in the results of this study. Seventy-two hours after transplantation, mRNA levels and SMAD4B proteins were measured in HCT120 cells. In addition, the researchers in this study investigated whether miR451 was associated with SMAD4B-directed control of CRC growth and migration. It was found that SMAD4B is highly expressed in both CRC and para-cancer tissues while using the TCGA database to detect SMAD4B expression. Patients with CRC with SMAD4B have a severe prognosis. MiR451 is sensitive to depressive disorders by targeting SMAD4B, according to these studies. We found that miR451 inhibited cell growth and migration, made CRC cells more readily available in chemotherapy, and did so by targeting SMAD4B. The findings suggest that miR451 and its genetic predisposition, SMAD4B, may help predict the prognosis and course of cancer patients. Treatments that target the miR451/SMAD4B axis may be helpful to people with CRC.

miR‑451 suppresses the malignant characteristics of colorectal cancer via targeting SAMD4B

Cancer metastasis and recurrence are major causes of poor survival in patients with colorectal cancer (CRC). Therefore, the biological behavior of microRNA (miR)‑451 in CRC deserves further investigation. Reverse transcription‑quantitative PCR was applied to measure the relative expression of miR‑451 in blood serum specimens from patients with CRC and CRC cells. In vitro, HCT116 cells were transfected with miR‑451 mimics, a miR‑451 inhibitor, or SAMD4B plasmids. Proliferation, migration and apoptosis were measured using CCK‑8, Transwell assays and flow cytometry, respectively. Luciferase reporter assay was used to identify targets of miR‑451 and western blotting performed to explore the internal mechanisms of miR‑451 regulation. In vivo, the effect of miR‑451 and SAMD4B plasmids on tumor growth was analyzed using a nude mouse xenograft model. Results indicated that serum miR‑451 expression was lower in patients with CRC compared with healthy controls. Patients with elevated expression of miR‑451 had longer survival times compared with those with low expression. Overexpression of miR‑451 inhibited proliferation and migration, promoted apoptosis and enhanced the sensitivity of CRC cells to chemotherapy. SAMD4B was identified as a direct target of miR‑451 using miRNA target prediction programs and dual luciferase reporter assay validated the binding site of miR‑451 in the 3‑'UTR region of SAMD4B. Further studies confirmed that miR‑451 inhibited CRC progression via targeting SAMD4B. Results indicated that miR‑451 is essential for blocking tumor growth via targeting SAMD4B in vivo and in vitro. The miR‑451/SAMD4B axis may serve as a novel therapeutic target in patients with CRC.

Encorafenib, binimetinib and cetuximab combined therapy for patients with BRAFV600E mutant metastatic colorectal cancer

Approximately 10-15% of colorectal cancers (CRCs) harbor an activating BRAF mutation, leading to tumor growth promotion by activation of the mitogen-activated protein kinases pathway. BRAFV600E mutations are prognostic for treatment failure after first-line systemic therapy in the metastatic setting. In contrast to the efficacy of combined BRAF and MEK inhibition in melanoma, BRAFV600E mutant CRC is intrinsically unresponsive due to upregulation of HER/EGFR. However, combining the EGFR inhibitor cetuximab, the BRAF inhibitor encorafenib and the MEK inhibitor binimetinib improves overall survival. This review discusses the current treatment field for patients with BRAFV600E mutant metastatic CRC and summarizes the pharmacology, efficacy and safety of the novel doublet and triplet therapies consisting of encorafenib and cetuximab with or without binimetinib.

MicroRNAs in the prognosis and therapy of colorectal cancer: From bench to bedside

MicroRNAs (miRNAs) are small, single-stranded, noncoding RNAs that can post-transcriptionally regulate the expression of various oncogenes and tumor suppressor genes. Dysregulated expression of many miRNAs have been shown to mediate the signaling pathways critical in the multistep carcinogenesis of colorectal cancer (CRC). MiRNAs are stable and protected from RNase-mediated degradation, thereby enabling its detection in biological fluids and archival tissues for biomarker studies. This review focuses on the role and application of miRNAs in the prognosis and therapy of CRC. While stage II CRC is potentially curable by surgical resection, a significant percentage of stage II CRC patients do develop recurrence. MiRNA biomarkers may be used to stratify such high-risk population for adjuvant chemotherapy to provide better prognoses. Growing evidence also suggests that miRNAs are involved in the metastatic process of CRC. Certain of these miRNAs may thus be used as prognostic biomarkers to identify patients more likely to have micro-metastasis, who could be monitored more closely after surgery and/or given more aggressive adjuvant chemotherapy. Intrinsic and acquired resistance to chemotherapy severely hinders successful chemotherapy in CRC treatment. Predictive miRNA biomarkers for response to chemotherapy may identify patients who will benefit the most from a particular regimen and also spare the patients from unnecessary side effects. Selection of patients to receive the new targeted therapy is becoming possible with the use of predictive miRNA biomarkers. Lastly, forced expression of tumor suppressor miRNA or silencing of oncogenic miRNA in tumors by gene therapy can also be adopted to treat CRC alone or in combination with other chemotherapeutic drugs.

Nucleotide excision repair and response and survival to chemotherapy in colorectal cancer patients

Several new chemotherapeutic agents have become available for the treatment of colorectal cancer, which has led to increased complexity in treatment planning. Treatment decision making for individual patients could be facilitated if guided by predictive and prognostic markers. As most cytotoxic drugs induce DNA damage, the DNA damage repair pathways hold potential for yielding such biomarkers. Here, we review the current evidence of a possible involvement of the nucleotide excision repair pathway in the efficacy of chemotherapeutic agents used in the treatment of colorectal cancer. Although a large number of studies have been conducted, they are generally of moderate size and heterogeneous in design. Up to date no firm conclusions can be drawn to translate these results into the clinic. We recommend further comprehensive investigations of the nucleotide excision repair pathway in large patient studies that include both discovery and validation cohorts.

Treatment of metastatic colorectal cancer: focus on panitumumab

Targeted agents are an important therapeutic option in the treatment of metastatic colorectal cancer (mCRC). Panitumumab is a recombinant, fully humanized, immunoglobulin G2 monoclonal antibody that targets the epidermal growth factor receptor (EGFR) with efficacy in mCRC as monotherapy and in combination with chemotherapy. Kirsten rat sarcoma (KRAS) mutation status has emerged as an important biomarker to predict response to anti-EGFR therapy. Optimal timing for panitumumab use in the mCRC treatment algorithm has not been established. This review discusses the mechanism of action, predictive biomarkers, and role of panitumumab in the treatment of mCRC.