Expression of the Sonic Hedgehog pathway components in clear cell renal cell carcinoma

Acquired cystic disease-associated renal cell carcinoma with PTCH1 mutation: a case report

Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is an extremely rare kidney tumor seen mainly in patients with end-stage renal disease. Currently, there are few reports on this type of tumor. We describe the case of a 58-year-old man who had been receiving peritoneal dialysis for more than nine years due to chronic renal insufficiency and uremia. One year after undergoing left renal clear cell renal cell carcinoma resection, a space-occupying lesion was found in the right kidney for which he underwent right nephrectomy. The histopathology of this tumor showed solid or tubular cell arrangements, with some areas of cyst formation. Vacuoles of varying sizes were present in the cytoplasm, and varying amounts of calcium oxalate crystals were found in the tumor cells or interstitium. The pathological diagnosis was ACD-RCC. Next-generation sequencing detected mutations in the PTCH1, MTOR, FAT1, SOS1, RECQL4, and CDC73 genes in the right renal tumor. This is a rare case of a patient with ACD-RCC in the right kidney and clear cell renal cell carcinoma in the left kidney. The findings suggest that mutations in PTCH1 associated with ACD-RCC may have acted as oncogenic drivers for the development of ACKD-RCC, together with providing insight into mechanisms underlying ACD-RCC development, as well as diagnostic and treatment options.

The immunoreactivity of GLI1 and VEGFA is a potential prognostic factor in kidney renal clear cell carcinoma

Kidney renal clear cell carcinoma (KIRC) is the most common type of kidney cancer and its pathogenesis is strongly associated with VHL-HIF-VEGF signaling. SHH ligand is the upstream SHH pathway regulator, while GLI1 is its major effector that stimulates as a transcription factor, i.a. expression of VEGFA gene. The aim of present study was to assess the prognostic significance of SHH, GLI1 and VEGFA immunoreactivity in KIRC tissues. The analysis included paired tumor and normal samples from 34 patients with KIRC. The immunoreactivity of SHH, GLI1 and VEGFA proteins was determined by immunohistochemical (IHC) renal tissues staining. The IHC staining results were assessed using the immunoreactive score (IRS) method which takes into account the number of cells showing a positive reaction and the intensity of the reaction. Increased GLI1 protein immunoreactivity was observed in KIRC tissues, especially in early-stage tumors, according to the TNM classification. Elevated expression of the VEGFA protein was noted primarily in high-grade KIRC samples according to the Fuhrman/WHO/ISUP scale. Moreover, a directly proportional correlation was observed between SHH and VEGFA immunoreactivity in TNM 3 + 4 and Fuhrman/ISUP/WHO 3 + 4 tumor tissues as well as in samples of patients with shorter survival. We also observed an association between shorter patient survival as well as increased and decreased immunoreactivity, of the VEGFA and GLI1, respectively. The aforementioned findings suggest that the expression pattern of SHH, GLI1 and VEGFA demonstrates prognostic potential in KIRC.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

Targets for Renal Carcinoma Growth Control Identified by Screening FOXD1 Cell Proliferation Pathways

Simple Summary

FOXD1 regulates the proliferation of clear cell renal cell carcinoma (ccRCC) cells, and ccRCC cells in which FOXD1 has been inactivated do not form tumors efficiently in an animal model. Reproducing growth inhibition in tumor cells by inhibiting FOXD1 pathways presents a possible therapeutic approach for ccRCC and other cancers. We have established an analysis strategy to identify FOXD1-regulated target pathways that may be therapeutically tractable, and compounds that modulate these pathways were selected for testing. Targets in three pathways were identified: FOXM1, PME1, and TMEM167A, which were inhibited by compounds FDI-6, AMZ-30, and silibinin, respectively. The effects of these compounds on the growth of tumor cells from patients cultured in a novel 3D tumor-replica culture environment revealed that FDI-6 and silibinin had strong growth inhibitory effects. This investigation informs new therapeutic targets to control ccRCC tumor growth, and provides a strategy to compare the responsiveness of individual patient tumor replicas to growth-inhibitory compounds.

Abstract

Clinical association studies suggest that FOXD1 is a determinant of patient outcome in clear cell renal cell carcinoma (ccRCC), and laboratory investigations have defined a role for this transcription factor in controlling the growth of tumors through regulation of the G2/M cell cycle transition. We hypothesized that the identification of pathways downstream of FOXD1 may define candidates for pharmacological modulation to suppress the G2/M transition in ccRCC. We developed an analysis pipeline that utilizes RNA sequencing, transcription factor binding site analysis, and phenotype validation to identify candidate effectors downstream from FOXD1. Compounds that modulate candidate pathways were tested for their ability to cause growth delay at G2/M. Three targets were identified: FOXM1, PME1, and TMEM167A, which were targeted by compounds FDI-6, AMZ-30, and silibinin, respectively. A 3D ccRCC tumor replica model was used to investigate the effects of these compounds on the growth of primary cells from five patients. While silibinin reduced 3D growth in a subset of tumor replicas, FDI-6 reduced growth in all. This study identifies tractable pathways to target G2/M transition and inhibit ccRCC growth, demonstrates the applicability of these strategies across patient tumor replicas, and provides a platform for individualized patient testing of compounds that inhibit tumor growth.

The Significance of INHBE Expression in the Cancer Cells of Clear-Cell Renal Cell Carcinoma

BACKGROUND

Activins and inhibins are structurally related dimeric glycoprotein hormones belonging to the transforming growth factor-β superfamily but whether they are also involved in malignancy is far from clear. No study has reported the expression of INHBE in kidney cancer. The purpose of this study was to examine the expressions of INHBE in the tumor tissue of patients with clear-cell renal cell carcinoma (ccRCC) and to explore the pathologic significance.

METHODS

The INHBE mRNA expression in the tumor tissue of ccRCC patients was analyzed by using RNA sequencing data from the TCGA database. To examine the expression of inhibin βE protein, 241 ccRCC patients were recruited and immunohistochemistry was performed on the tumor tissue of these patients along with 39 normal renal samples. The association between the inhibin βE expression level and patient's clinicopathological indices was evaluated.

RESULTS

In the normal renal tissue, inhibin βE was found to be expressed mainly by renal tubular epithelial cells. In the tumor tissue, inhibin βE was expressed mainly in cancer cells. The expressions of INHBE mRNA and protein in the tumor tissue of ccRCC patients increased significantly compared with those in normal renal samples. There was a significant correlation between the level of inhibin βE in the tumor tissue and tumor grade. Patients with a lower inhibin βE expression in the tumor tissue were found to have a longer overall survival and disease-specific survival.

CONCLUSIONS

INHBE might be involved in the pathogenesis of ccRCC and function as a tumor promoter.

Sonic Hedgehog signaling pathway in gynecological and genitourinary cancer (Review)

Cancers of the urinary tract, as well as those of the female and male reproductive systems, account for a large percentage of malignancies worldwide. Mortality is frequently affected by late diagnosis or therapeutic difficulties. The Sonic Hedgehog (SHH) pathway is an evolutionary conserved molecular cascade, which is mainly associated with the development of the central nervous system in fetal life. The present review aimed to provide an in‑depth summary of the SHH signaling pathway, including the characterization of its major components, the mechanism of its upstream regulation and non‑canonical activation, as well as its interactions with other cellular pathways. In addition, the three possible mechanisms of the cellular SHH cascade in cancer tissue are discussed. The aim of the present review was to summarize significant findings with regards to the expression of the SHH pathway components in kidney, bladder, ovarian, cervical and prostate cancer. Reports associated with common deficits and de‑regulations of the SHH pathway were summarized, despite the differences in molecular and histological patterns among these malignancies. However, currently, neither are SHH pathway elements included in panels of prognostic/therapeutic molecular patterns in any of the discussed cancers, nor have the drugs targeting SMO or GLIs been approved for therapy. The findings of the present review may support future studies on the treatment of and/or molecular targets for gynecological and genitourinary cancers.

SPOP-PTEN-SUFU axis promotes progression of clear cell renal cell carcinoma via activating SHH and WNT pathway

Although E3 ligase Speckle type BTB/POZ protein (SPOP) promotes tumorigenesis by acting as a key regulatory hub in clear cell renal cell carcinoma (ccRCC), the detailed molecular mechanism remains unclear. Here, we demonstrate that a well-known tumor suppressor, Suppressor of Fused (SUFU), is downregulated by SPOP. Interestingly, this downregulation depends on cullin-3(Cul3)-SPOP E3 ligase, but SUFU is not a direct substrate of SPOP. Phosphatase and tensin homolog (PTEN), a ubiquitinated substrate of SPOP, is involved in SPOP-mediated SUFU reduction. Importantly, inhibition of SUFU leads to elevated SHH and WNT signaling, consequently rescuing the reduced proliferation, migration, and invasion abilities of ccRCC cells caused by SPOP-knockdown. Moreover, combinatorial treatment with SHH and WNT inhibitors shows more effective for suppressing ccRCC cell proliferation and aggressiveness. These findings demonstrate that a novel SPOP–PTEN–SUFU axis promotes ccRCC carcinogenesis by activating SHH and WNT pathway, providing a new treatment strategy for ccRCC.

Systemic Multi-Omics Analysis Reveals Amplified P4HA1 Gene Associated With Prognostic and Hypoxic Regulation in Breast Cancer

Breast cancer (BC) is a common malignant tumor in females around the world. While multimodality therapies exist, the mortality rate remains high. The hypoxic condition was one of the potent determinants in BC progression. The molecular mechanisms underpinning hypoxia and their association with BC can contribute to a better understanding of tailored therapies. In this study, two hypoxic induced BC transcriptomic cohorts (GSE27813 and GSE47533) were assessed from the GEO database. The P4HA1 gene was identified as a putative candidate and significantly regulated in hypoxic BC cells compared to normal BC cells at different time intervals (6 h, 9 h, 16 h, 32 h, and 48 h). In patients with Luminal (p < 1E-12), triple-negative subclasses (p = 1.35059E-10), Stage 1 (p = 8.8817E-16), lymph node N1 (p = 1.62436E-12), and in the 40–80 age group (p = 1.62447E-12), the expression of P4HA1 was closely associated with the clinical subtypes of BC. Furthermore, at the 10q22.1 chromosomal band, the P4HA1 gene displayed a high copy number elevation and was associated with a poor clinical regimen with overall survival, relapse-free survival, and distant metastases-free survival in BC patients. In addition, using BioGRID, the protein–protein interaction (PPI) network was built and the cellular metabolic processes, and hedgehog pathways are functionally enriched with GO and KEGG terms. This tentative result provides insight into the molecular function of the P4HA1 gene, which is likely to promote hypoxic-mediated carcinogenesis, which may favor early detection of BC and therapeutic stratification.

Downregulation of miR-506-3p Facilitates EGFR-TKI Resistance through Induction of Sonic Hedgehog Signaling in Non-Small-Cell Lung Cancer Cell Lines

Non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation eventually develop resistance to EGFR-targeted tyrosine kinase inhibitors (TKIs). Treatment resistance remains the primary obstacle to the successful treatment of NSCLC. Although drug resistance mechanisms have been studied extensively in NSCLC, the regulation of these mechanisms has not been completely understood. Recently, increasing numbers of microRNAs (miRNAs) are implicated in EGFR-TKI resistance, indicating that miRNAs may serve as novel targets and may hold promise as predictive biomarkers for anti-EGFR therapy. MicroRNA-506 (miR-506) has been identified as a tumor suppressor in many cancers, including lung cancer; however, the role of miR-506 in lung cancer chemoresistance has not yet been addressed. Here we report that miR-506-3p expression was markedly reduced in erlotinib-resistant (ER) cells. We identified Sonic Hedgehog (SHH) as a novel target of miR-506-3p, aberrantly activated in ER cells. The ectopic overexpression of miR-506-3p in ER cells downregulates SHH signaling, increases E-cadherin expression, and inhibits the expression of vimentin, thus counteracting the epithelial-mesenchymal transition (EMT)-mediated chemoresistance. Our results advanced our understanding of the molecular mechanisms underlying EGFR-TKI resistance and indicated that the miR-506/SHH axis might represent a novel therapeutic target for future EGFR mutated lung cancer treatment.

circPTCH1 promotes invasion and metastasis in renal cell carcinoma via regulating miR-485-5p/MMP14 axis

Background: Circular RNAs (circRNAs) are a new class of non-coding RNAs (ncRNAs) that are derived from exons or introns by special selective shearing. circRNAs have been shown to play critical roles in various human cancers. However, their roles in renal cell carcinoma (RCC) and the underlying mechanisms remain largely unknown.

Methods: A novel circRNA-circPTCH1, was identified from a microarray analysis of five paired RCC tissues. Then, we validated its expression and characterization through qRT-PCR, gel electrophoresis, RNase R digestion assays and Sanger sequencing. Functional experiments were performed to determine the effect of circPTCH1 on RCC progression both in vitro and in vivo. The interactions between circPTCH1 and miR-485-5p were clarified by RNA pull-down, luciferase reporter and RNA immunoprecipitation (RIP) assays.

Results: We observed that circPTCH1 was up-regulated in RCC cell lines and tumor samples, and higher levels of circPTCH1 were significantly correlated with worse patient survival, advanced Fuhrman grade and greater risk of metastases. Elevated circPTCH1 expression led to increased migration and invasion of RCC cells both in vitro and in vivo whereas silencing circPTCH1 decreased migration and invasion and impeded the epithelial-mesenchymal transition (EMT) of RCC cells. Mechanistically, we elucidated that circPTCH1 could directly bind miR-485-5p and subsequently suppress expression of the target gene MMP14.

Conclusion: circPTCH1 promotes RCC metastasis via the miR-485-5p/MMP14 axis and activation of the EMT process. Targeting circPTCH1 may represent a promising therapeutic strategy for metastatic RCC.