RBM10-TFE3 fusions: A FISH-concealed anomaly in adult renal cell carcinomas displaying a variety of morphological and genomic features: Comprehensive study of six novel cases

Multiple Omics Analysis of the Role of RBM10 Gene Instability in Immune Regulation and Drug Sensitivity in Patients with Lung Adenocarcinoma (LUAD)

OBJECTIVE

The RNA-binding protein RBM10 can regulate apoptosis during the proliferation and migration of pancreatic cancer, endometrial cancer, and osteosarcoma cells; however, the molecular mechanism underlying lung adenocarcinoma is rarely reported. Recent studies have detected multiple truncated and missense mutations in RBM10 in lung adenocarcinoma, but the role of RBM10 in lung adenocarcinoma is unclear. This study mainly explored the immune regulation mechanism of RBM10 in the development of lung adenocarcinoma and its influence on sensitivity to targeted therapy drugs.

METHODS

The transcriptome data of CGAP were used to analyze the RNA-seq data of lung adenocarcinoma patients from different subgroups by using the CIBERSORT algorithm to infer the relative proportion of various immune infiltrating cells, and Spearman correlation analysis was performed to determine the gene expression and immune cell content. In addition, this study utilized drug trial data from the GDSC database. The IC50 estimates for each specific targeted therapy were obtained by using a regression method, and the regression and prediction accuracy were tested via ten cross-validations with the GDSC training set. An immunohistochemical test was performed on the samples of 20 patients with lung adenocarcinoma in the subcomponent analysis of immune cells, and the protein expression of RBM10 in lung adenocarcinoma tissues was verified by cellular immunofluorescence assays. Nucleic acids were extracted at low temperatures, and qRT-PCR was used to verify the expression levels of the mRNA of RBM10 in lung adenocarcinoma tissues and normal tissues (p < 0.05).

RESULTS

After screening and inclusion using a machine language, the results showed that RBM10 was significantly highly expressed in the lung adenocarcinoma tissues. The related signaling pathways were mainly concentrated in ncRNA processing, rRNA metabolic processes, ribosome biogenesis, and the regulation of translation. The qRT-PCR for 20 lung adenocarcinoma tissues showed that the expression of RBM10 in these tissues was significantly different from that in normal tissues (p = 0.0255). Immunohistochemistry analysis and cell immunofluorescence staining also confirmed that RBM10 was involved in the immune regulation of lung adenocarcinoma tissues, and the number of immune cell aggregations was significantly higher than that of the control group. RBM10 regulates B cell memory-CIBERSORT (p = 0.042) and B cell memory-CIBERSOTRT-abs (p = 0.027), cancer-associated fibroblast-EPIC (p = 0.001), cancer-associated fibroblast- MCPCounter (p = 0.0037), etc. The risk score was significantly associated with the sensitivity of patients to lapatinib (p = 0.049), nilotinib (p = 0.015), pazopanib (p = 0.001), and sorafenib (p = 0.048).

CONCLUSIONS

RBM10 can inhibit the proliferation and invasion of lung adenocarcinoma cells through negative regulation and promote the apoptosis of lung adenocarcinoma cells through immunomodulatory mechanisms. The expression level of RBM10 affects the efficacy of targeted drug therapy and the survival prognosis of lung adenocarcinoma patients, which has a certain guiding significance for the clinical treatment of these patients.

TFE3 gene rearrangement and protein expression contribute to a poor prognosis of renal cell carcinoma

Background

TFE3-rearranged renal cell carcinoma (TFE3-rearranged RCC) is a type of kidney cancer with a low incidence, with no consensus about whether it has a worse prognosis than clear cell renal cell carcinoma (ccRCC). This study attempted to elucidate the impact of TFE3-rearranged RCC by analyzing its clinical features and prognosis.

Methods

Patients treated in Sun Yat-sen Memorial Hospital (SYSMH) who were suspected to be diagnosed with TFE3-rearranged RCC were divided into two groups, TFE3-rearranged RCC and ccRCC with positive TFE3 protein expression on immunohistochemistry [TFE3(+) ccRCC], by dual-color, break-apart fluorescence in situ hybridization (FISH). After balancing the baseline characteristics with TFE3(+) ccRCC using the propensity score matching (PSM) method in a ratio of 2, we selected patients diagnosed with ccRCC with negative TFE3 protein expression on immunohistochemistry [TFE3(-) ccRCC]. The impact of TFE3 gene rearrangement and protein expression on renal cell carcinoma was determined by feature comparison with a nonparametric test and survival analysis with the Kaplan‒Meier method.

Results

Among 37 patients suspected of having TFE3-rearranged RCC, 13 patients were diagnosed with TFE3-rearranged RCC, and 24 patients had TFE3(+) ccRCC. The recurrence and new metastasis of TFE3-rearranged RCC was relatively common, even if the tumor stage was early at the first diagnosis. Through feature comparison and survival analysis, we found that TFE3-rearranged RCC was quite similar to TFE3(+) ccRCC. Compared with TFE3(-) ccRCC, TFE3(+) ccRCC tended to have a larger tumor diameter (P = 0.011), higher neutrophil/lymphocyte ratio (NLR) (P = 0.017) and metastatic potential (P = 0.022), and worse overall survival (OS) (P = 0.043) and PFS (P = 0.016). The survival analysis showed that TFE3-rearranged RCC had a worse PFS than ccRCC (P = 0.002), and TFE3(+) RCC had a worse PFS than TFE3(-) RCC (P = 0.001). According to the stratification system based on the combination of TFE3 and lymphovascular invasion (LVI), we further found that the prognosis from good to poor was TFE3(-) LVI(-), TFE3(+) LVI(-), TFE3(+) LVI(+) and TFE3(-) LVI(+), with statistically significant differences in both OS (P = 0.001) and PFS (P < 0.001). In addition, we also reported two cases with poor prognosis, of which one was TFE3-rearranged RCC and the other was TFE3(+) ccRCC.

Conclusions

This is a novel finding that both FISH confirmed TFE3 gene rearrangement-mediated TFE3-rearranged RCC and IHC confirmed positive TFE3 protein expression [TFE3(+)] contribute to a poor prognosis in RCC, suggesting more active treatment and careful follow-up for TFE3(+) RCC patients. The combination of TFE3 and LVI may be a new risk stratification system for RCC.

MiTF/TFE Translocation Renal Cell Carcinomas: From Clinical Entities to Molecular Insights

MiTF/TFE translocation renal cell carcinoma (tRCC) is a rare and aggressive subtype of RCC representing the most prevalent RCC in the pediatric population (up to 40%) and making up 4% of all RCCs in adults. It is characterized by translocations involving either TFE3 (TFE3-tRCC), TFEB (TFEB-tRCC) or MITF, all members of the MIT family (microphthalmia-associated transcriptional factor). TFE3-tRCC was first recognized in the World Health Organization (WHO) classification of kidney cancers in 2004. In contrast to TFEB-tRCC, TFE3-tRCC is associated with many partners that can be detected by RNA or exome sequencing. Both diagnoses of TFE3 and TFEB-tRCC are performed on morphological and immunohistochemical features, but, to date, TFE break-apart fluorescent in situ hybridization (FISH) remains the gold standard for diagnosis. The clinical behavior of tRCC is heterogeneous and more aggressive in adults. Management of metastatic tRCC is challenging, especially in the younger population, and data are scarce. Efficacy of the standard of care-targeted therapies and immune checkpoint inhibitors remains low. Recent integrative exome and RNA sequencing analyses have provided a better understanding of the biological heterogeneity, which can contribute to a better therapeutic approach. We describe the clinico-pathological entities, the response to systemic therapy and the molecular features and techniques used to diagnose tRCC.

Chameleon TFE3-translocation RCC and How Gene Partners Can Change Morphology: Accurate Diagnosis Using Contemporary Modalities

Translocation renal cell carcinoma (tRCC) with TFE3 gene rearrangements has been born as a distinct entity 20 years ago. These relatively rare tumors were notable among other RCC subtypes because of their disproportionally high incidence among children and young adults. Initial reports were focused on describing unifying morphologic criteria and typical clinical presentation. Follow-up studies of ancillary immunohistochemical and hybridization techniques provided additional diagnostic tools allowing recognition of tRCC tumors in practice. However, a growing body of literature also expanded the clinicomorphologic spectrum of tRCCs, to include a significant morphologic overlap with other RCC variants thus blurring the diagnostic clarity of this entity. More recent molecular studies utilizing next-generation sequencing technology accelerated recognition of numerous novel gene partners fusing at different breakpoints with the TFE3 gene. Accumulating data indicates that morphologic and clinical heterogeneity of tRCC could be explained by fusion subtypes, and knowledge of TFE3 partnering genes may be important in predicting tumor behavior. Herein we provided a comprehensive analysis of ∼400 tRCC cases with known TFE3 fusion partners, estimated their relative incidence and summarized clinicomorphologic features associated with most common fusion subtypes. Our data was based on an extensive literature review and had a special focus on comparing immunohistochemistry, fluorescent in situ hybridization and contemporary molecular studies for the accurate diagnosis of tRCC.