The genetic profiling of renal tumors has revealed genomic regions commonly affected by structural changes and a general genetic heterogeneity. The VHL, PTEN, and BAP1 genes are often mutated in renal tumors. The frequency and clinical relevance of these mutations in renal tumors are still being researched. In our study, we investigated VHL, PTEN, and BAP1 genes and the sequencing of 24 samples of patients with renal tumors, revealing that VHL was mutated at a noticeable frequency (25%). Six of the investigated samples showed mutations, and one genetic polymorphism (rs779805) was detected in both heterozygote and homozygote forms. PTEN gene mutation was observed in only one sample, and one specimen showed genetic polymorphism. In the case of the BAP1 gene, all of the samples were wild types. Interestingly, VHL mutation was detected in two female patients diagnosed with AML and in one with oncocytoma. We assume that VHL or PTEN mutations may contribute to the development of human renal cancer. However, the overall mutation rate was low in all specimens investigated, and the development and prognosis of the disease were not exclusively associated with these types of genetic alterations.

Bladder cancer (BC) is the tenth most frequently detected cancer in both sexes. Type-I luteinizing hormone-releasing hormone (LHRH) receptor (LHRH-R-I) is expressed not only in the pituitary, but also in several types of cancer disease. There are few data about LHRH-R-I expression in human BC. This study aimed to investigate the expression of LHRH and LHRH-R-I in the transitional cell carcinoma (TCC) type of human BC. RNA was extracted from 24 human bladder tumor specimens and three BC cell lines. RT-PCR was performed to detect mRNA for LHRH and LHRH-R-I. The protein of LHRH-R-I was further studied by immunohistochemistry (IHC), ligand competition assay, and Western Blot. PCR products of LHRH were found in 19 of 24 (79%) specimens and mRNA of LHRH-R-I was detected in 20 of 24 specimens (83%). Positive immunostaining for LHRH-R-I with different expression intensity was found in all samples examined, showing negative correlation with TCC grade. Radioligand binding studies also showed the presence of specific LHRH-R-I and high affinity binding of LHRH analogs. The high incidence of LHRH-R in BC suggests that it could serve as a molecular target for therapy of human BC with cytotoxic LHRH analogs or modern powerful antagonistic analogs of LHRH.

Background: Programmed cell death protein-1 (PD-1) and its ligands, PD-L1 and PD-L2, constitute a central immune checkpoint pathway that regulates T-cell activity and tumor immune escape, while their relationship with STAT signaling remains incompletely understood in ccRCC. Methods: We analyzed 27 paired ccRCC and adjacent non-tumorous human kidney tissue samples. mRNA levels of PD-1, PD-L1, PD-L2, STAT1, and STAT3 were quantified by RT-qPCR. In addition, representative human ccRCC cell lines (CAKI-2 and A-498) were treated with IFN-γ to assess the time-dependent modulation of immune checkpoint molecules and STAT pathway activation. Results: PD-L1 and PD-L2 were significantly upregulated in tumor tissues compared with adjacent normal kidney tissue. Exploratory observation suggests grade dependent increase. Whereas PD-1 was predominantly downregulated, IFN-γ treatment induced a rapid transcriptional upregulation of PD-L1 and PD-L2 in RCC cell lines, with maximal protein accumulation observed at 72 h. STAT1, but not STAT3, exhibited dynamic induction following IFN-γ stimulation, showing temporal association with PD-L1 and PD-L2 upregulation, indicating cell-line-specific regulatory effects. Correlation analyses confirmed a strong correlation between PD-1 and its ligands, whereas STAT1 and STAT3 expression showed no direct association with PD-L1 or PD-L2 levels in cancer samples. Conclusions: Our findings demonstrate that PD-L1 and PD-L2 are frequently upregulated in ccRCC and dynamically regulated by IFN-γ/STAT1-dependent signaling. Our results provide additional insight into the mechanisms of immune escape and underscore the potential of integrated profiling of PD-1 ligands and STAT signaling to guide personalized immunotherapeutic strategies in ccRCC.

Background: Shikonin, a natural compound derived from Lithospermum erythrorhizon, exhibits anticancer properties by inducing apoptosis in various tumor types, including clear cell renal cell carcinoma (ccRCC) cell lines CAKI-2 and A-498. This study investigates the mechanisms underlying shikonin-induced apoptosis, focusing on microRNAs miR-15b, miR-99b, and miR-181a in ccRCC. Materials and Methods: ccRCC cells were treated with 5 µM shikonin. Expression levels of miR-15b, miR-99b, and miR-181a were measured by TaqMan PCR. Apoptosis-related targets (AKT3, PDCD4, FOXO1, FOXO3, JNK1, and LAMTOR3) were identified in silico and validated by qRT-PCR and Western blot. Spearman’s correlation was used to evaluate miRNA–target relationships. Ingenuity Pathway Analysis explored relevant pathways. Results: Shikonin decreased miR-15b, miR-99b, and miR-181a levels in CAKI-2 cells, whereas these miRNAs were increased in A-498 cells, demonstrating cell-line-specific effects. qRT-PCR and Western blot confirmed changes in target expression, suggesting regulation by these miRNAs. In A-498 cells, miR-181a expression positively correlated with the studied target levels during 24–72 h of treatment, indicating that its potential regulatory role may be cell-type-dependent. MiR-15b and miR-99b showed linear correlations with targets in both cell lines, but expression patterns differed, suggesting direct regulation alongside potential involvement in additional pathways contributing to shikonin-induced apoptosis. Conclusions: Shikonin induces apoptosis in renal cancer cells by modulating the MAPK/ERK pathway and through cell-line-specific, cell-type-dependent regulation of miR-15b, miR-99b, and miR-181a. These findings highlight the importance of cell-type-dependent miRNA regulation and underscore the therapeutic potential of shikonin in ccRCC.

Immunotherapy has become one of the primary forms of cancer treatment. The inhibition of immune checkpoint molecules, including indoleamine 2,3-dioxygenase (IDO), is a promising approach for immunotherapy. Phosphatase and tensin homolog (PTEN) is well known as a tumor suppressor that antagonizes oncogenic signaling molecules/pathways and plays a key role in the prognosis and (immuno)therapy of the disease. In this study, twenty healthy and tumorous renal tissue pairs were investigated, and the mRNA (RT-qPCR) and protein (Western blot) expression of IDO and PTEN were analyzed. In two cancer cell lines (CAKI-2; A-498), the protein of IDO and PTEN was measured followed by IDO induction with interferon alpha-2 (IFN-α2). According to our results, a significantly higher mRNA expression of IDO and PTEN was found in tumorous tissues compared to the adjacent healthy kidney specimens. The mRNA expression of IDO and PTEN showed a positive correlation in 80% of the sample pairs. Western blot results confirmed the protein expression of both IDO and PTEN. In the cell lines, immunocytochemistry showed that IDO is inducible with IFN-α2. In summary, our results suggest that IDO expression may play a role in the development of renal cancer, and IDO as well as PTEN might be potential biomarkers for patients with RCC.

Renal cell carcinoma (RCC) is frequently resistant to tyrosine kinase inhibitors (TKIs) such as sunitinib, limiting therapeutic efficacy. ATP-binding cassette (ABC) transporters, including ABCB1, ABCB5, and ABCG2, are important transporters implicated in multidrug resistance, influencing drug efflux and tumor progression. We aimed to evaluate the expression of ABCB1, ABCB5, and ABCG2 in human RCC tissues and human renal cancer cell lines CAKI-2 and A-498, and to investigate their potential association with sunitinib resistance and associated signaling pathways. Twenty paired tumorous and adjacent non-tumorous human kidney tissue samples were analyzed for ABC transporter gene expression using qRT-PCR. RCC cell lines CAKI-2 and A-498, including sunitinib-resistant derivatives, were treated with 40 µM sunitinib. The levels of transporters and key signaling proteins were assessed by Western blot. ABCG2 was consistently higher in tumorous tissues, and ABCB1 and ABCB5 showed grade-dependent increases in tumors. Resistant cells exhibited elevated ABCB1 and dynamic ABCB5 and ABCG2 expression patterns compared to sensitive cells, indicating an association between altered transporter expression and the resistant phenotype. Sunitinib treatment modulated signaling pathways, with differential activation of PI3K/Akt, NF-κB, and MAPK/ERK observed in sensitive versus resistant cells. Our findings suggest that altered ABCB1 and ABCG2 expression may be associated with the development of sunitinib resistance in RCC and may be linked to changes in key survival signaling pathways. These findings provide a basis for future functional studies investigating the role of ABC transporters in sunitinib resistance and may contribute to the development of personalized therapeutic strategies in RCC.