The expressed mutational landscape of microsatellite stable colorectal cancers

The Status Quo of Pharmacogenomics of Tyrosine Kinase Inhibitors in Precision Oncology: A Bibliometric Analysis of the Literature

Precision oncology and pharmacogenomics (PGx) intersect in their overarching goal to institute the right treatment for the right patient. However, the translation of these innovations into clinical practice is still lagging behind. Therefore, this study aimed to analyze the current state of research and to predict the future directions of applied PGx in the field of precision oncology as represented by the targeted therapy class of tyrosine kinase inhibitors (TKIs). Advanced bibliometric and scientometric analyses of the literature were performed. The Scopus database was used for the search, and articles published between 2001 and 2023 were extracted. Information about productivity, citations, cluster analysis, keyword co-occurrence, trend topics, and thematic evolution were generated. A total of 448 research articles were included in this analysis. A burst of scholarly activity in the field was noted by the year 2005, peaking in 2017, followed by a remarkable decline to date. Research in the field was hallmarked by consistent and impactful international collaboration, with the US leading in terms of most prolific country, institutions, and total link strength. Thematic evolution in the field points in the direction of more specialized studies on applied pharmacokinetics of available and novel TKIs, particularly for the treatment of lung and breast cancers. Our results delineate a significant advancement in the field of PGx in precision oncology. Notwithstanding the practical challenges to these applications at the point of care, further research, standardization, infrastructure development, and informed policymaking are urgently needed to ensure widespread adoption of PGx.

Deviating Alternative Splicing as a Molecular Subtype of Microsatellite Stable Colorectal Cancer

PURPOSE

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Biomarkers to aid in prognostication and treatment decisions are in high demand, and to facilitate their development, a better understanding of the underlying biology of the highly heterogeneous disease is needed.

METHODS

A genome-scale alternative splicing (AS) analysis using RNA-sequencing data from primary microsatellite stable (MSS) CRCs from 127 patients was performed. Splice variant-specific expression levels of individual cancer samples were compared with the total set of samples, and a metric for a tumor sample's global amount of deviating AS was developed. This metric varied considerably across the cohort and ranged from 6 to 282 deviating AS events per tumor sample. A threshold of 45 or more deviating events was set to distinguish cancers with high (n = 44) and low (n = 83) levels of deviating AS.

RESULTS

Patients with high amounts of AS deviations had significantly shorter time to relapse compared with patients with fewer deviations (P = .04). Furthermore, differential gene expression analysis revealed nine known cancer-critical genes that are significantly upregulated in samples with high amounts of deviating AS. Validation of the results in an independent cohort of MSS CRCs showed the same tendency toward shorter progression-free survival among the high-deviation group. In both cohorts, enrichment for growth factors was identified among upregulated genes associated with this phenotype.

CONCLUSION

There is a large variation in the amount of deviating AS among MSS CRCs, and we provide evidence that those with high amounts of deviations represent different cancer biology.

Up-Regulation of SH3TC2 Induced by YTHDF1 Predicts Poor Outcome and Facilitates Cell-Cycle Progress in Colorectal Cancer

N6-methyladenosine (m6A) modification plays a crucial role in determining the fate and function of RNA transcripts in tumor cells. Nevertheless, how m6A regulates the expression of key molecules and coordinates its involvement in the development of colorectal cancer (CRC) remains largely unclear. Here, we report that the m6A reading protein YTHDF1-mediated up-regulation of SH3TC2 promotes CRC growth both in vitro and in vivo. In a pan-cancer analysis across more than thirty types of cancer, we found that SH3TC2 was dysregulated in nine cancers, including BLCA, CHOL, COAD, LAML, PAAD, READ, SKCM, BRCA, and TGCT, and was closely associated with patient prognosis in four cancers, including COAD, MESO, PAAD, and READ. In particular, SH3TC2 was overexpressed in CRC as confirmed by six independent study cohorts. Clinically, high expression of SH3TC2 predicted worse disease-free survival (DFS) in CRC patients. SH3TC2 showed fascinating diagnostic value and was correlated with immunosuppression in CRC. Functionally, RNA-sequencing combined with experiments revealed that knockdown of SH3TC3 significantly inhibited cell-cycle progress of CRC, impairing cell growth. Mechanistically, YTHDF1 protein directly binds with SH3TC2 mRNA and promotes its elevation in an m6A-dependent manner. Thus, our findings provide a mechanism to target the YTHDF1/SH3TC2 axis for CRC therapy.