Comprehensive Genomic Landscape in Chinese Clear Cell Renal Cell Carcinoma Patients

PD1/PD-L1 blockade in clear cell renal cell carcinoma: mechanistic insights, clinical efficacy, and future perspectives

The advent of PD1/PD-L1 inhibitors has significantly transformed the therapeutic landscape for clear cell renal cell carcinoma (ccRCC). This review provides an in-depth analysis of the biological functions and regulatory mechanisms of PD1 and PD-L1 in ccRCC, emphasizing their role in tumor immune evasion. We comprehensively evaluate the clinical efficacy and safety profiles of PD1/PD-L1 inhibitors, such as Nivolumab and Pembrolizumab, through a critical examination of recent clinical trial data. Furthermore, we discuss the challenges posed by resistance mechanisms to these therapies and potential strategies to overcome them. We also explores the synergistic potential of combination therapies, integrating PD1/PD-L1 inhibitors with other immunotherapies, targeted therapies, and conventional modalities such as chemotherapy and radiotherapy. In addition, we examine emerging predictive biomarkers for response to PD1/PD-L1 blockade and biomarkers indicative of resistance, providing a foundation for personalized therapeutic approaches. Finally, we outline future research directions, highlighting the need for novel therapeutic strategies, deeper mechanistic insights, and the development of individualized treatment regimens. Our work summarizes the latest knowledge and progress in this field, aiming to provide a valuable reference for improving clinical efficacy and guiding future research on the application of PD1/PD-L1 inhibitors in ccRCC.

Exploration of Morphological Features of Clear Cell Renal Cell Carcinoma With PBRM1, SETD2, BAP1, or KDM5C Mutations

The last decade has seen great advances in genomic profiling and prognosis-associated factors of clear cell renal cell carcinoma (RCC), the most common entity in kidney cancer. Following VHL, PBRM1, SETD2, BAP1, and KDM5C have been validated as the most common co-occurring gene mutations in clear cell RCC by multicenter studies. However, the morphological features of clear cell RCC with co-occurring gene mutations remain unclear. In this study, we presented 20 clear cell RCCs that underwent next-generation sequencing, of which 1 tumor was reclassified as ELOC-mutated RCC. PBRM1, SETD2, BAP1, and KDM5C were the most common mutations, following VHL. Morphologically, clear cell RCC with PBRM1 or KDM5C mutation usually displayed a low-grade pattern. Cystic changes and hyalinized stroma were often observed. The Ki67 index was <10%. These observations indicated good prognosis. However, mutated SETD2 may increase the malignancy of clear cell RCC with PBRM1 mutation. Two clear cell RCCs with mutated PBRM1 and SETD2 developed local or distant metastases. Clear cell RCC with BAP1 mutations always had high-grade patterns, and rhabdoid differentiation was also observed, indicating that BAP1 mutation was associated with poor outcomes. Papillary architecture was often a feature of BAP1 mutation, which is uncommon in clear cell RCC. PDL1 was positive in only one tumor with BAP1 mutation, and the positivity rate was limited to 5%. B7H3 was negative in all tumors. Morphologic findings in this small cohort may suggest why PBRM1 mutation does not correlate with decreased survival, whereas BAP1 mutation usually predicts poor outcomes.

Genomic profiles of renal cell carcinoma in a small Chinese cohort

Objectives

Our aim was to describe the molecular characteristics of Renal Cell Carcinoma (RCC) and develop a small panel of RCC-associated genes from a large panel of cancer-related genes.

Materials and methods

Clinical data of 55 patients with RCC diagnosed in four hospitals from September 2021 to August 2022 were collected. Among the 55 patients, 38 were diagnosed with clear cell RCC (ccRCC), and the other 17 were diagnosed with non-clear cell RCC (nccRCC), including 10 cases of papillary renal cell carcinoma, 2 cases of hereditary leiomyomatosis and RCC syndrome (HLRCC), 1 eosinophilic papillary RCC, 1 tubular cystic carcinoma, 1 TFE3 gene fusion RCC, and 2 RCC with sarcomatoid differentiation. For each patient, 1123 cancer-related genes and 79 RCC-associated genes were analyzed.

Results

The most frequent mutations in a large panel of 1123 cancer-related genes in the overall population of RCC patients were VHL (51%), PBRM1 (35%), BAP1 (16%), KMT2D (15%), PTPRD (15%), and SETD2 (15%). For ccRCC patients, mutations in VHL, PBRM1, BAP1, and SERD2 can reach 74%, 50%, 24%, and 18%, respectively, while for nccRCC patients, the most frequent mutation was FH (29%), MLH3 (24%), ARID1A (18%), KMT2D (18%), and CREBBP (18%). The germline mutation rate in all 55 patients reached 12.7% (five with FH, one with ATM, and one with RAD50). The small panel containing only 79 RCC-associated genes demonstrated that mutations of VHL, PBRM1, BAP1, and SETD2 in ccRCC patients were 74%, 50%, 24%, and 18% respectively, while for the nccRCC cohort, the most frequent mutations were FH (29%), ARID1A (18%), ATM (12%), MSH6 (12%), BRAF (12%), and KRAS (12%). For ccRCC patients, the spectrum of mutations by large and small panels was almost the same, while for nccRCC patients, the mutation spectrum showed some differences. Even though the most frequent mutations (FH and ARID1A) in nccRCC were both demonstrated by large panels and small panels, other less frequent mutations such as MLH3, KMT2D, and CREBBP were not shown by the small panel.

Conclusion

Our study revealed that nccRCC is more heterogeneous than ccRCC. For nccRCC patients, the small panel shows a more clear profile of genetic characteristics by replacing MLH3, KMT2D, and CREBBP with ATM, MSH6, BRAF, and KRAS, which may help predict prognosis and make clinical decisions.

Prevalence of germline mutations in cancer susceptibility genes in Chinese patients with renal cell carcinoma

Background

Germline pathogenic variants are estimated to affect 3-5% of patients with renal cell carcinoma (RCC). The identification of patients with hereditary RCC is important for cancer screening and treatment guidance.

Methods

Whole-exome sequencing (WES) (n=69) or gene panel sequencing containing 139 genes (n=54) related to germline cancer predisposition was used to analyze germline mutations in 123 patients with RCC admitted to Department of Urology, The Third Medical Center of Chinese PLA General Hospital. Chi-square test (χ²) was used to analyze relationship between clinicopathologic parameters and germline mutations.

Results

A total of 13 (10.57%) patients carried pathogenic or likely pathogenic germline mutations in 10 cancer predisposition genes, including VHL, FH, FLCN, SDHB, MUTYH, RAD51C, NBN, RAD50, FANCI, and FANCM. A total of 6 of these 10 cancer predisposition genes were associated with maintenance of genomic stability and DNA repair. Patients harboring pathogenic germline mutations tended to have an earlier RCC onset. The prevalence of deleterious mutations was higher in patients with bilateral or multifocal RCC compared to patients without bilateral or multifocal RCC. Patients with non-clear cell RCC (nccRCC) were significantly more likely to have RCC-associated gene mutations.

Conclusions

To our knowledge, this is the first report of pathogenic germline mutations in the FANCI and FANCM genes and heterozygous germline missense mutation in exon 5 of the FH gene c.563A>T:p.N188I in RCC. Young RCC patients, patients with bilateral or multifocal RCC, or patients with nccRCC are more likely to have pathogenic/potentially pathogenic germline mutations.

Increased expression of the RNA-binding protein Musashi-2 is associated with immune infiltration and predicts better outcomes in ccRCC patients

RNA-binding proteins (RBPs) mainly contribute to abnormalities in posttranscriptional gene regulation. The RBP Musashi-2, an evolutionarily conserved protein, has been characterized as an oncoprotein in various tumors. However, the prognostic value and potential roles of Musashi-2 in clear cell renal cell carcinoma (ccRCC) have not yet been elucidated. In this study, we found that Musashi-2 was mainly expressed in the normal distal tubular cells and collecting duct cells of the kidneys, while its expression was significantly decreased in ccRCC. And higher expression levels of Musashi-2 indicated better overall survival (OS) in ccRCC. Furthermore, immunohistochemistry demonstrated that PD-L1 expression was negatively correlated with Musashi-2 expression, and Musashi-2 was found to be remarkably correlated with multiple immune cells and immune inhibitors, including CD8+ T cells, CD4+ T cells, regulatory T (Treg) cells, PDCD1, CTLA4, Foxp3, and LAG3. Functional enrichment analysis revealed that Musashi-2 might be involved in ccRCC metabolic reprogramming and immune infiltration and further predicted the therapeutic sensitivity of ccRCC. Taken together, Musashi-2 is a prognostic biomarker for ccRCC patients that may provide novel insights into individualized treatment strategies and guide effective immunotherapy.