HoxC6 Functions as an Oncogene and Isoform HoxC6-2 May Play the Primary Role in Gastric Carcinogenesis

Development of an exosome-related and immune microenvironment prognostic signature in colon adenocarcinoma

Background: The correlation between exosomes and the tumor immune microenvironment has been proved to affect tumorigenesis and progression of colon adenocarcinoma (COAD). However, it remained unclear whether exosomes had an impact on the prognostic indications of COAD patients.

Methods: Expression of exosome-related genes (ERGs) and clinical data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. The ERGs associated with prognosis were identified and exosome-related prognostic signature was constructed. Patients in two risk groups were classified according to the risk score calculation formula: Risk score = 1.0132 * CCKBR + 0.2416 * HOXC6 + 0.7618 * POU4F1. The expression of three ERGs was investigated by qRT-PCR. After that, we developed a nomogram predicting the likelihood of survival and verified its predictive efficiency. The differences of tumor immune microenvironment, immune cell infiltration, immune checkpoint and sensitivity to drugs in two risk groups were analyzed.

Results: A prognostic signature was established based on the three ERGs (CCKBR, HOXC6, and POU4F1) and patients with different risk group were distinguished. Survival analysis revealed the negative associated of risk score and prognosis, ROC curve analyses showed the accuracy of this signature. Three ERGs expression was investigated by qRT-PCR in three colorectal cancer cell lines. Moreover, risk score was positively correlated with tumor mutational burden (TMB), immune activities, microsatellite instability level, the expression of immune checkpoint genes. Meanwhile, the expression level of three ERGs and the risk score were markedly related with the sensitive response to chemotherapy.

Conclusion: The novel signature composed of three ERGs with precise predictive capabilities can be used to predict prognosis and provide a promising therapeutic target for improving the efficacy of immunotherapy.

HOXC6/8/10/13 predict poor prognosis and associate with immune infiltrations in glioblastoma

BACKGROUND

Glioblastoma (GBM), characterized by deregulated cell proliferation and immune cells infiltration, is a common and lethal tumor of the central nervous system. Recently, the infiltration of immune cells has attracted attention as a potential novel GBM immunotherapy option. Homeobox C cluster (HOXC) is an evolutionarily conserved family of transcriptional factors that are involved in embryogenesis and tumorigenesis. Nevertheless, the correlations of HOXCs with the prognosis and immune infiltration of GBM remain blurred.

METHODS

The RNA-seq data with corresponding clinical characteristics were downloaded from TCGA and GTEx databases. The correlations between HOXCs and clinical characteristics were calculated using univariable and multivariate Cox regression. R language with ggplot2, survminer, survival, GSVA, and pROC packages were employed to analyze the data and present the plots. MethSurv, UALCAN and cBioPortal were employed to evaluate the DNA methylation and mutation status of HOXCs in GBM. We also verified the expression and prognosis of HOXCs by qPCR and immunohistochemistry in a cohort of 36 patients.

RESULTS

We identified that HOXC6/8/10/13 were crucial biomarkers for diagnosis and prognostic judgement in GBM. Gene set variation analysis revealed that levels of expression of HOXCs were associated with the infiltration of various immune cells. The qPCR and immunohistochemistry data validated the prognostic values of HOXC6/8/10/13 in GBM. Finally, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that HOXCs might be involved in DNA-binding transcription activator activity and the apelin signaling pathway.

CONCLUSION

This research highlights that HOXC6/8/10/13 are involved in the immune infiltrates, also provide potential clinical utility as therapeutic targets in GBM.

RSF1 in cancer: interactions and functions

RSF1, remodelling and spacing factor 1, is an important interphase centromere protein and is overexpressed in many types of cancers and correlated with poor overall survival. RSF1 has functions mainly in maintaining chromosome stability, facilitating DNA repair, maintaining the protein homeostasis of RSF1 and suppressing the transcription of some oncogenes when RSF1 protein is expressed at an optimal level; however, RSF1 overexpression facilitates drug resistance and cell cycle checkpoint inhibition to prompt cancer proliferation and survival. The RSF1 expression level and gene background are crucial for RSF1 functions, which may explain why RSF1 has different functions in different cancer types. This review summarizes the functional domains of RSF1, the overexpression status of RSF1 and SNF2H in cancer based on the TCGA and GTE_X databases, the cancer-related functions of RSF1 in interacting with H2Aub, HDAC1, CENP-A, PLK1, ATM, CENP-S, SNF2H, HB_X, BubR1, cyclin E1, CBP and NF-κB and the potential clinical value of RSF1, which will lay a theoretical foundation for the structural biology study of RSF1 and application of RSF1 inhibitors, truncated RSF1 proteins and SNF2H inhibitors in the treatment of RSF1-overexpressing tumours.

Homeobox proteins are potential biomarkers and therapeutic targets in gastric cancer: a systematic review and meta-analysis

BACKGROUND

An increasing number of studies have described the aberrant expression of homeobox (HOX) proteins in gastric cancer (GC), which is critically associated with the prognosis and clinicopathological characteristics of GC. This study was conducted to investigate the clinical value and action mechanisms of HOX proteins in GC.

METHODS

A comprehensive search of PubMed, Embase, Web of Science and Cochrane Library was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. The pooled hazard ratio (HR) with its 95% confidence interval (95% CI) and the pooled odds ratio (OR) with its 95% CI were used to assess the effect of HOX protein expression on the prognosis and clinicopathological features of GC, respectively.

RESULTS

Nineteen studies containing 3775 patients were selected for this study. Heterogeneity among HRs of overall survival (OS) was markedly high (I2 = 90.5%, p = 0.000). According to the subgroup analysis, increased expression of HOX protein in the downregulated subgroup was associated with a good prognosis for patients with GC (pooled HR: 0.46, 95% CI: 0.36-0.59, I2 = 3.1%, p = 0.377), while overexpression of HOX protein in the upregulated subgroup was correlated with a reduced OS (pooled HR: 2.59, 95% CI: 1.79-3.74, I2 = 73.5%, p = 0.000). The aberrant expression of HOX protein was crucially related to the TNM stage, depth of tumour invasion, tumour size, lymph node metastasis, distant metastasis, vascular invasion, histological differentiation and Lauren classification in patients with GC. In addition, the molecular mechanisms by which HOX proteins regulate tumorigenesis and development of GC were also explored.

CONCLUSIONS

HOX proteins play vital roles in GC progression, which might serve as prognostic markers and therapeutic targets for GC.

Increased HOXC6 mRNA expression is a novel biomarker of gastric cancer

In this study, we aimed to investigate the molecular biomarkers that are pivotal for the development and progression of gastric cancer (GC). We analyzed clinical specimens using RNA sequencing to identify the target genes. We found that the expression of HOXC6 mRNA was upregulated with the progression of cancer, which was validated by quantitative real time PCR and RNA in-situ hybridization. To compare the protein expression of HOXC6, we evaluated GC and normal gastric tissue samples using western blot analysis and immunohistochemistry. We detected significantly higher levels of HOXC6 in the GC tissues than in the normal controls at both mRNA and protein levels. The expression levels of HOXC6 mRNA in patients with advanced gastric cancer (AGC) were significantly higher than those in patients with early gastric cancer (EGC). Kaplan-Meier curves showed that high expression of HOXC6 mRNA is significantly associated with poor clinical prognosis. Our findings suggest that HOXC6 mRNA may be a novel biomarker and can be potentially valuable in predicting the prognosis of GC patients. Especially, HOXC6 mRNA in-situ hybridization may be a diagnostic tool for predicting prognosis of individual GC patients.