The frequency and clinical profile of patients with stage III non-small cell lung cancer harboring KRAS mutations have not yet been well documented. Here, we analyzed hotspot KRAS mutations using high-resolution melting analyses in tumor specimens from patients who received chemoradiotherapy between January 2001 and December 2010 at the National Cancer Center Hospital. The associations between the presence of KRAS mutations and the response rate, relapse-free survival, first relapse sites, survival post-progression and overall survival were investigated. A total of 274 non-squamous non-small cell lung cancer patients received chemoradiotherapy at our hospital. After excluding 121 patients for whom tumor specimens were not available and 34 patients with EGFR mutations, the remaining 119 patients were included in the analysis. KRAS mutations were found at a frequency of 13%. Patients with KRAS mutations had a shorter median relapse-free survival (6.1 vs 10.9 months) and a lower response rate (63% vs 81%). As for the first relapse site, patients with KRAS mutations had fewer local relapses (8% vs 23%) and more brain metastases (46% vs 12%). After disease progression, patients with KRAS mutations had a significantly shorter median survival post-progression (2.5 vs 7.3 months, P = 0.028) and median overall survival (15.1 vs 29.1 months, P = 0.022). Our results suggested that KRAS mutation could be associated with a reduced efficacy of chemoradiotherapy and a shortened survival time.
Abstract Background Noninvasive detection of early stage cancers with accurate prediction of tumor tissue-of-origin could improve patient prognosis. Because miRNA profiles differ between organs, circulating miRNomics represent a promising method for early detection of cancers, but this has not been shown conclusively. Methods A serum miRNA profile (miRNomes)–based classifier was evaluated for its ability to discriminate cancer types using advanced machine learning. The training set comprised 7931 serum samples from patients with 13 types of solid cancers and 5013 noncancer samples. The validation set consisted of 1990 cancer and 1256 noncancer samples. The contribution of each miRNA to the cancer-type classification was evaluated, and those with a high contribution were identified. Results Cancer type was predicted with an accuracy of 0.88 (95% confidence interval [CI] = 0.87 to 0.90) in all stages and an accuracy of 0.90 (95% CI = 0.88 to 0.91) in resectable stages (stages 0-II). The F1 score for the discrimination of the 13 cancer types was 0.93. Optimal classification performance was achieved with at least 100 miRNAs that contributed the strongest to accurate prediction of cancer type. Assessment of tissue expression patterns of these miRNAs suggested that miRNAs secreted from the tumor environment could be used to establish cancer type–specific serum miRNomes. Conclusions This study demonstrates that large-scale serum miRNomics in combination with machine learning could lead to the development of a blood-based cancer classification system. Further investigations of the regulating mechanisms of the miRNAs that contributed strongly to accurate prediction of cancer type could pave the way for the clinical use of circulating miRNA diagnostics.
Background: Biobankers have been unexpectedly involved in the pandemic of COVID-19 since early 2020. Although specific guidance was not available, the International Society for Biological and Environmental Repositories (ISBER) Best Practices and the ISO 20387 document have been utilized to deal with the pandemic disaster. The ISO experts and best practice experts in ISBER teamed up to share the available information and learn the experiences of biobanks concerning COVID-19 through organizing webinars, surveys, and town hall meetings. Four ISBER regional ambassadors (RAs) from the Indo-Pacific Rim (IPR) region were also actively involved at one of the town hall meetings. These RAs, who are from Australia, India, Indonesia, and Japan, and the Director-at-Large of the region, have summarized their experiences in this article.
Alternative splicing is a fundamental process of gene regulation that contributes to protein diversity, a common phenomenon in the mammalian genome. Alternative splicing events not only happen in the normal gene regulation process, but are also closely related to certain diseases, including cancer. In this review, we briefly demonstrate the proof of concept (POC) of the relationship between alternative splicing and DNA damage, and describe the associations among alternative splicing and cancer pathogenesis, DNA damage, and gastrointestinal cancers. We discuss whether alternative splicing leads to genetic instability, which is considered to be a driving force for tumorigenesis. FUSE-binding protein (FBP) -interacting repressor (FIR) is a c-myc transcriptional suppressor. A splice variant of FIR that lacks exon 2 in the transcriptional repressor domain (FIRΔexon2), upregulates c-myc transcription by inactivating wild-type FIR. FIR+/- mice exhibited marked c-myc mRNA upregulation, particularly in the peripheral blood (PB), without any significant pathogenic phenotype. Because the single knockout of TP53 generates thymic lymphoma, FIR+/-TP53-/- mice developed T-cell type acute lymphocytic/lymphoblastic leukemia (T-ALL) with increased organ or bone marrow invasion and showed a poor prognosis. After describing the POC of alternative splicing of FIR in DNA damage and carcinogenesis, clinical application for cancer diagnosis and treatment by FIR/FIRΔexon2 was briefly summarized. Chiba University has prepared a biobank to support studies to develop biomarker detection, molecular diagnosis, and "Omics" research. In conclusion, alternative splicing of FIR, generating FIRΔexon2, potentially contributes to not only colorectal carcinogenesis, but also leukemogenesis, and a better understanding of the role and mechanism of alternative splicing in tumorigenesis may reveal new directions for cancer biomarker detection.
The occurrence of inactivating mutations in SWI/SNF chromatin-remodeling genes in common cancers has attracted a great deal of interest. However, mechanistic strategies to target tumor cells carrying such mutations are yet to be developed. This study proposes a synthetic-lethality therapy for treating cancers deficient in the SWI/SNF catalytic (ATPase) subunit, BRG1/SMARCA4. The strategy relies upon inhibition of BRM/SMARCA2, another catalytic SWI/SNF subunit with a BRG1-related activity. Immunohistochemical analysis of a cohort of non-small-cell lung carcinomas (NSCLC) indicated that 15.5% (16 of 103) of the cohort, corresponding to preferentially undifferentiated tumors, was deficient in BRG1 expression. All BRG1-deficient cases were negative for alterations in known therapeutic target genes, for example, EGFR and DDR2 gene mutations, ALK gene fusions, or FGFR1 gene amplifications. RNA interference (RNAi)-mediated silencing of BRM suppressed the growth of BRG1-deficient cancer cells relative to BRG1-proficient cancer cells, inducing senescence via activation of p21/CDKN1A. This growth suppression was reversed by transduction of wild-type but not ATPase-deficient BRG1. In support of these in vitro results, a conditional RNAi study conducted in vivo revealed that BRM depletion suppressed the growth of BRG1-deficient tumor xenografts. Our results offer a rationale to develop BRM-ATPase inhibitors as a strategy to treat BRG1/SMARCA4-deficient cancers, including NSCLCs that lack mutations in presently known therapeutic target genes.
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