Analysis of metastasis associated signal regulatory network in colorectal cancer

Mitochondrial ribosomal proteins in metastasis and their potential use as prognostic and therapeutic targets

The mitochondrion is an essential cell organelle known as the powerhouse of the cell. Mitochondrial ribosomal proteins (MRPs) are nuclear encoded, synthesised in the cytoplasm but perform their main functions in the mitochondria, which includes translation, transcription, cell death and maintenance. However, MRPs have also been implicated in cancer, particularly advanced disease and metastasis across a broad range of cancer types, where they play a central role in cell survival and progression. For some, their altered expression has been investigated as potential prognostic markers, and/or therapeutic targets, which is the focus of this review. Several therapies targeting MRPs are currently approved by the Food and Drug Administration and the European Medicines Agency for use in other diseases, revealing the opportunity for repurposing their use in advanced and metastatic cancer. Herein, we review the evidence supporting key MRPs as molecular drivers of advanced disease in multiple cancer types. We also highlight promising avenues for future use of MRPs as precision targets in the treatment of late-stage cancers for which there are currently very limited effective treatment options.

Research Progress on the Relationship Between Inflammation and Colorectal Cancer

Colorectal cancer is one of the common malignant tumors. Relevant epidemiology and a large number of experimental studies have proved that chronic inflammation is highly correlated with the occurrence and development of colorectal cancer. And inflammatory bowel disease has been proven to be an independent risk factor for colorectal cancer. Various inflammatory cells participate in the establishment of the chronic inflammatory intestinal microenvironment required for the onset of colorectal cancer. The abnormal signal pathways mediated by various inflammatory factors and inflammatory mediators promote the occurrence of tumors, which are related to colorectal cancer and pathogenesis-related inflammation mechanisms. At the gene level, miRNAs can also affect the pathogenesis of colorectal cancer by regulating mesenchymal epithelial transformation. This article reviews the relationship between inflammation and colorectal cancer as well as the related inflammatory mechanisms.

Global analysis of RNA-protein interactions in TNF-α induced alternative splicing in metabolic disorders

In this report, using the database of RNA-binding protein specificities (RBPDB) and our previously published RNA-seq data, we analyzed the interactions between RNA and RNA-binding proteins to decipher the role of alternative splicing in metabolic disorders induced by TNF-α. We identified 13 395 unique RNA-RBP interactions, including 385 unique RNA motifs and 35 RBPs, some of which (including MBNL-1 and 3, ZFP36, ZRANB2, and SNRPA) are transcriptionally regulated by TNF-α. In addition to some previously reported RBPs, such as RBMX and HuR/ELAVL1, we found a few novel RBPs, such as ZRANB2 and SNRPA, to be involved in the regulation of metabolic syndrome-associated genes that contain an enrichment of tetrameric RNA sequences (AUUU). Taken together, this study paves the way for novel RNA-protein interaction-based therapeutics for treating metabolic syndromes.

A newly identified small molecular compound acts as a protein kinase inhibitor to suppress metastasis of colorectal cancer

BACKGROUND

Targeted therapy has demonstrated high efficacy in the treatment of advanced cancer, and protein kinase inhibitors are a major focus of that therapy; therefore, our study aimed to identify a new protein kinase inhibitor that could be used in the treatment of advanced cancers.

METHODS

We analyzed the expression profile of colorectal cancer (CRC), combined the driver gene and drug target databases, and identified protein kinase kalirin RhoGEF kinase (kalirin/KALRN) which is related to CRC metastasis. Based on the structure of kalirin, we screened for the small molecular compound ZINC65387069. We first compared the kinase inhibitory activities and molecular properties of ZINC65387069 and tyrosine kinase inhibitors (TKIs). We then determined the effects of ZINC65387069 on the phosphorylation of protein kinase B-Raf. Finally, we determined the effects of ZINC65387069 on migration and apoptosis of HCT116 cells as well as RKO cells. The cell cytoskeleton was also determined.

RESULTS

Compared with traditional TKIs, ZINC65387069 had stronger kinase inhibitory activity, a simpler structure, higher water solubility, a smaller polar surface area, and lower molecular weight and volume. In CRC cells, ZINC65387069 could significantly inhibit the phosphorylation of B-Raf as well as inhibit cell migration, destroy the cell cytoskeleton, and promote cell apoptosis.

CONCLUSION

ZINC65387069 is a newly identified protein kinase inhibitor that deserves additional research as a lead compound for drug development to help create targeted therapy against CRC.

Downregulation of miR-654-3p in Colorectal Cancer Indicates Poor Prognosis and Promotes Cell Proliferation and Invasion by Targeting SRC

Background

MicroRNAs (miRNAs), such as miR-654-3p, regulate gene expression at the post-transcriptional level affecting malignant tumor behavior. However, the expression levels, function, and mechanism of miR-654-3p in colorectal cancer (CRC) are unknown.

Methods

The expression levels of miR-654-3p and SRC in 103 CRC tissues and matched normal colorectal tissues were detected by a quantitative real-time polymerase chain reaction (qRT-PCR). miR-654-3p was overexpressed by RNA mimics and SRC knockdown by siRNA. Function-based experiments were carried out to detect the proliferation and migration abilities in CRC cell lines. Flow cytometry assay was performed to evaluate the effect of miR-654-3p on cell apoptosis and cycle distribution. Xenograft tumor models in nude mice were utilized to evaluate miR-654-3p functions in vivo. Dual-fluorescence reporter assay was used to verify the direct binding between miR-654-3p and SRC.

Results

miR-654-3p was downregulated in CRC tissues as compared to matched normal colorectal tissues. The expression levels of miR-654-3p were closely associated with distant metastasis. In addition, elevated expression of miR-654-3p in CRC patients prolonged the overall survival. Upregulated miR-654-3p significantly suppressed the proliferation and migration capacity of CRC cells by enhancing apoptosis and promoting G0/G1 phase arrest. The direct binding between miR-654-3p and SRC was verified by the dual-luciferase reporter gene. Furthermore, the suppression of proliferation and migration capacity by elevated miR-654-3p level could be reversed by overexpressing SRC.

Conclusion

miR-654-3p acts as a tumor suppressor through regulating SRC. It might also serve as a diagnostic and prognostic indicator and a novel molecular target for CRC therapy.

Cutaneous metastasis of ascending colon cancer harboring a BRAF V600E mutation: A rare case report

RATIONALE

Cutaneous metastases from colorectal cancer are extremely rare and generally appear several years after diagnosis or resection of the primary colorectal tumor. Although cutaneous metastasis is unusual, it often indicates a poor prognosis.

PATIENT CONCERNS

We treated a 62-year-old woman with multiple cutaneous metastatic nodules on the chest, back, and armpit 7 months after resection of ascending colon cancer.

DIAGNOSES

The patient was diagnosed with cutaneous metastasis of ascending colon cancer with BRAF V600E mutation.

INTERVENTIONS

After 6 cycles of fluorouracil, leucovorin, oxaliplatin, cetuximab, and emurafenib, most of the metastatic lesions had begun to shrink, and no new metastases were observed. Serum tests showed that the levels of several tumor markers were decreased.

OUTCOMES

The patient responded well to treatment and survived for 6.5 months after presentation with skin metastasis.

LESSONS

Cutaneous metastasis of colorectal cancer with BRAF V600E mutation is a rare but important phenomenon that should not be ignored. Cutaneous metastasis of colorectal cancer frequently indicates advanced disease and poor prognosis. The SWOG 1406 program is one of the treatment options, but this needs further exploration.

Block of proliferation 1 promotes cell migration and invasion in human colorectal cancer cells via the JNK pathway

Metastasis is one of the most common causes of death in patients with colorectal cancer (CRC). Block of proliferation 1 (BOP1) regulates tumorigenesis, epithelial‐to‐mesenchymal transition, migration, metastasis, and drug resistance in several tumor types. However, the role of BOP1 in the regulation of colorectal cancer cell migration and invasion is still largely unclear. In this study, the results of immunohistochemistry showed that BOP1 was upregulated in our cohort of CRC patients. BOP1 knockdown inhibited the migration and invasion of CRC cells, confirmed by the downregulation of the mRNA levels of MMP‐2 and MMP‐9. The overexpression of BOP1 in CRC cells exerted the opposite effect. SP600125, an inhibitor of JNK signaling, partially abolished the BOP1 overexpression‐mediated increase in the migratory and invasive ability of CRC cells. Our results indicated that BOP1 is an important regulator of CRC cell invasion and migration, predominantly through the JNK signaling pathway.

A Robust 6-lncRNA Prognostic Signature for Predicting the Prognosis of Patients With Colorectal Cancer Metastasis

Objective: Our study aimed to construct a robust long non-coding RNA (lncRNA) prognostic signature for colorectal cancer (CRC) metastasis.

Methods: Differentially expressed lncRNAs were identified between metastatic CRC and non-metastatic CRC samples from The Cancer Genome Atlas Database (TCGA) using the edgeR package. The differentially expressed lncRNAs with prognosis of patients with CRC metastasis were identified by univariate Cox regression analysis, followed by a stepwise multivariate Cox regression model. The survminer package in R was used to identify the optimal cutoff point for high-risk and low-risk groups. The receiver operating characteristic (ROC) curves were plotted to assess this signature. To explore potential signaling pathways associated with these lncRNAs, Gene Set Enrichment Analysis (GSEA) was performed.

Results: A 6-lncRNA signature was built based on the lncRNA expression profile for CRC metastasis. The optimal cutoff value was used to classify high-risk and low-risk groups using the survminer package. The high-risk groups could have poorer survival time than the low-risk groups. ROC curve result indicated that this lncRNA signature had high sensitivity and accuracy. GSEA analysis results showed that the six lncRNAs were significantly enriched in several CRC metastasis-related signaling pathways such as “cell cycle,” “DNA replication,” “mismatch repair,” “oxidative phosphorylation,” “regulation of autophagy,” and “insulin signaling pathway.”

Conclusion: Our study constructed a 6-lncRNA model for predicting the survival outcomes of patients with CRC metastasis, which could become potential prognostic biomarkers, and therapeutic targets for CRC metastasis.

A Combined four-mRNA Signature Associated with Lymphatic Metastasis for Prognosis of Colorectal Cancer

Background: Colorectal cancer (CRC) is one of the most common malignant tumors in the world. Lymph node metastasis (LNM) is a common mode of metastasis of CRC. However, the combined mRNA biomarkers associated with LNM of CRC that can effectively predict CRC prognosis have not been reported yet.

Methods: To identify biomarkers that are associated with LNM, we collected data from the The Cancer Genome Atlas (TCGA) database. The edgeR package was searched to seek LNM-related genes by comparisons between cancer samples and normal colorectal tissues and between LNM and non-LNM (NLNM) of CRC. Univariate and multivariate regression analysis of genes in the intersection to build gene signature associated with independent prognosis of CRC, and then verified by Kaplan-Meier curve and log-rank test, receiver operating characteristic (ROC) curve was used to determine the efficiency of survival prediction of our four-mRNA signature. Finally, the potential molecular mechanisms and properties of these gene signature were also explored with functional and pathway enrichment analysis.

Results: 329 mRNAs were up-regulated in CRC tissues with LNM, and 8461 mRNAs were up-regulated in CRC tissues, the intersection is 100 mRNAs. After univariate and multivariate Cox regression analysis of 100 mRNAs, a novel four LNM related mRNAs (EPHA8, KRT85, GABRA3, and CLPSL1) were screened as independent prognostic indicators of CRC. Surprisingly, the four-mRNA signature can predict the prognosis of CRC patients independently of clinical factors andthe area under the curve (AUC) of the ROC is 0.730. The novel four-mRNA signature was used to identify high and low-risk groups. Stratified analysis indicated the risk score based on four-mRNA signature was an independent prognostic indicator for female, T3+T4, N1+N2 ,stage III+IV and patients with no new tumor event. Functional annotation of this risk model in high-risk patients revealed that pathways associated with neuroactive ligand-receptor interaction, estrogen signaling pathway, and steroid hormone biosynthesis.

Conclusions: By conducting TCGA data mining, our study demonstrated that a four-mRNA signature associated with LNM can be used as a combined biomarker for independent prognosis of CRC.