Piotr Popławski

BackgroundClear cell renal cell carcinoma (ccRCC) is characterized by frequent loss of primary cilia and dysregulation of hypoxia-related pathways associated with von Hippel–Lindau (VHL) deficiency. MicroRNAs contribute to ccRCC progression by modulating multiple cellular programs, including proliferation, adhesion, and invasion. Here, we investigated the expression and functional relevance of cilia-associated genes in ccRCC and examined the regulation and role of the Golgi- and cilia-associated protein TRIP11.Main bodyAmong 303 curated cilia-associated genes, 26 were significantly downregulated in ccRCC and associated with unfavorable patient survival. miR-155-5p, which was markedly upregulated in TCGA-KIRC tumors, was predicted to target 12 of the downregulated ciliary genes and was experimentally confirmed to directly repress TRIP11 expression in ccRCC cells. TRIP11 silencing increased proliferation, adhesion, and invasion in both ccRCC cell lines. In Caki-1 cells, TRIP11 knockdown additionally reduced migratory capacity and was accompanied by increased expression of PIK3C2A, MKI-67 and PAPOLA, whereas in VHL-deficient KIJ265T cells, it preferentially enhanced cell viability and altered the expression of stress- and signalling-related genes, including ROMO1 and PSENEN. Across TCGA-KIRC tumours, TRIP11 expression showed a strong positive correlation with VHL (R = 0.59, p < 0.0001) and with a cilium- and vesicle-associated transcriptional program, and was decreased in higher-stage and higher-grade disease.ConclusionOur findings identify TRIP11 as a miR-155-5p-regulated Golgi- and cilia-associated protein whose reduced expression is associated with enhanced malignant properties of ccRCC cells. These results support further investigation of TRIP11-related pathways in renal cancer progression.

Psoriasis is a chronic inflammatory autoimmune skin disease for which no standardised and reliable molecular biomarkers of disease course or activity are currently available. Here, we aimed to identify serum biomarkers of psoriasis. Serum samples from 40 patients with psoriasis and 40 healthy volunteers were analysed using ELISA and Proximity Extension Assay proteomics. ELISA revealed significantly increased serum levels of AGO2 and APOA1 in psoriatic patients versus controls, with a strong association between APOA1 and psoriasis (OR = 20.72, 95% CI of 4.57–93.87, p = 0.000137). Targeted serum proteomics additionally identified 35 differentially expressed proteins, including well-known psoriasis drivers (e.g., top upregulated IL17A and SERPINB4). The most downregulated was adrenomedullin (ADM, FC = −10.12). For 14 altered proteins, no previous direct associations with psoriasis were reported. Among them, DEFB103A_DEFB103B and DSG3 showed the best discrimination between psoriasis and control samples, while SERPINB4 correlated with psoriasis severity. APOA1, DEFB103A_DEFB103B, and DSG3 emerge as novel candidate circulating psoriasis biomarkers, and SERPINB4 as a biomarker of psoriasis severity. The functional role of DSG3 and other newly identified proteins (ACRV1, HAO1, ADH4, GPD1, GFER, PTGES2, DSG3, AFAP1L1, GALNT3, RASGRP2, MAP2K6, LXN, NBEAL2, and VPS54) in psoriasis requires further studies.

Mesenchymal stem/stromal cells (MSCs) are multipotent cells that support wound healing. Tumours, often called as wounds that do not heal, recruit MSCs, which in turn support tumour growth. The immunomodulatory MSCs properties are facilitated under hypoxic conditions, while tumours are often hypoxic and immune-suppressed. It is unclear how MSCs wound healing actions are prevented in tumours. Here, we found that renal cancer cells secrete amphiregulin which induces MSCs recruitment and facilitates tumour growth in vivo. In MSCs, AREG triggers HIF1A degradation and transcriptional reprogramming, leading to glycolytic switch, increased migration and attenuation of immunoregulatory profile. In renal cancer cells, AREG stimulates expression of oncogenic proteins, including AKR1C3, leading to increased tumour growth and angiogenesis. To our knowledge, this is the first study showing that glycolytic switch in MSCs is induced by cancer. Our study provides insight into how renal cancer cells attenuate MSCs wound pro-healing properties to facilitate tumour growth.

Renal cell cancer is the most frequent kidney malignancy. Most RCC cases are classified as clear cell renal cell carcinoma (ccRCC), characterized by high aggressiveness and poor prognosis for patients. ccRCC aggressiveness is defined by classification systems based on changes in morphology of nucleoli, the membraneless substructures of nuclei. The latter act as the sites of ribosome biogenesis as well as the hubs that trap and immobilize proteins, preventing their action in other cellular compartments. Thereby, nucleoli control cellular functioning and homeostasis. Nucleoli are also the sites of activity of multiple noncoding RNAs, including snoRNAs, IGS RNA, and miRNAs. Recent years have brought several remarkable discoveries regarding the role of nucleolar non-coding RNAs, in particular snoRNAs, in ccRCC. The expression of snoRNAs is largely dysregulated in ccRCC tumors. snoRNAs, such as SNHG1, SNHG4 and SNHG12, act as miRNA sponges, leading to aberrant expression of oncogenes and tumor suppressors, and directly contributing to ccRCC development and progression. snoRNAs can also act without affecting miRNA functioning, by altering the expression of key oncogenic proteins such as HIF1A. snoRNAs are also potentially useful biomarkers of ccRCC progression. Here, we comprehensively discuss the role of nucleolar proteins and non-coding RNAs in ccRCC.

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Metabolic reprogramming is one of the hallmarks of renal cell cancer (RCC). We hypothesized that altered metabolism of RCC cells results from dysregulation of microRNAs targeting metabolically relevant genes. Combined large-scale transcriptomic and metabolic analysis of RCC patients tissue samples revealed a group of microRNAs that contribute to metabolic reprogramming in RCC. miRNAs expressions correlated with their predicted target genes and with gas chromatography-mass spectrometry (GC-MS) metabolome profiles of RCC tumors. Assays performed in RCC-derived cell lines showed that miR-146a-5p and miR-155-5p targeted genes of PPP (the pentose phosphate pathway) (G6PD and TKT), the TCA (tricarboxylic acid cycle) cycle (SUCLG2), and arginine metabolism (GATM), respectively. miR-106b-5p and miR-122-5p regulated the NFAT5 osmoregulatory transcription factor. Altered expressions of G6PD, TKT, SUCLG2, GATM, miR-106b-5p, miR-155-5p, and miR-342-3p correlated with poor survival of RCC patients. miR-106b-5p, miR-146a-5p, and miR-342-3p stimulated proliferation of RCC cells. The analysis involving >6000 patients revealed that miR-34a-5p, miR-106b-5p, miR-146a-5p, and miR-155-5p are PanCancer metabomiRs possibly involved in global regulation of cancer metabolism. In conclusion, we found that microRNAs upregulated in renal cancer contribute to disturbed expression of key genes involved in the regulation of RCC metabolome. miR-146a-5p and miR-155-5p emerge as a key “metabomiRs” that target genes of crucial metabolic pathways (PPP (the pentose phosphate pathway), TCA cycle, and arginine metabolism).

Thyroid hormone receptor beta (THRB) gene is commonly deregulated in cancers and, as strengthened by animal models, postulated to play a tumor-suppressive role. Our previous studies revealed downregulation of THRB in clear cell renal cell carcinoma (ccRCC), but the culpable mechanisms have not been fully elucidated. Since epigenetic regulation is a common mechanism influencing the expression of tumor suppressors, we hypothesized that downregulation of THRB in renal cancer results from epigenetic aberrances, including CpG methylation and microRNA-dependent silencing. Our study revealed that ccRCC tumors exhibited a 56% decrease in THRB and a 37% increase in DNA methyltransferase 1 (DNMT1) expression when compared with paired non-neoplastic control samples. However, THRB CpG methylation analysis performed using BSP, SNaPshot and MSP-PCR consistently revealed no changes in methylation patterns between matched tumor and control samples. In silico analysis resulted in identification of four microRNAs (miR-155, miR-425, miR-592, and miR-599) as potentially targeting THRB transcript. Luciferase assay showed direct binding of miR-155 and miR-425 to 3′UTR of THRB, and subsequent in vivo analyses revealed that transfection of UOK171 cell line with synthetic miR-155 or miR-425 resulted in decreased expression of endogenous TRHB by 22% and 64%, respectively. Finally, real-time PCR analysis showed significant upregulation of miR-155 (354%) and miR-425 (162%) in ccRCC when compared with matched controls. Moreover, microRNA levels were negatively correlated with the amount of THRB transcript in tissue samples. We conclude that CpG methylation is not the major mechanism contributing to decreased THRB expression in ccRCC. In contrast, THRB is targeted by microRNAs miR-155 and miR-425, whose increased expression may be responsible for downregulation of THRB in ccRCC tumors.

We show here that the promoter of E2F1 gene, encoding one of the key regulators of cell proliferation, is overly active in the presence of low amounts of triiodothyronine (T3) and in the presence of mutant thyroid hormone receptor. We also show that T3–thyroid hormone receptor pathway of regulation of molecular processes is disturbed in clear cell renal cell carcinoma (ccRCC) on several levels, including overexpression of thyroid hormone receptors and the disturbance of their binding to DNA and to the hormone. In comparison to the cancer-free kidneys and peritumoral respective control tissues, E2F1 mRNA and protein levels are significantly increased in cancer tissues. A significant correlation between E2F1 mRNA and protein levels has been found in both control types and ccRCCs. No correlation was observed between the amount of E2F1 mRNA and the amount of thyroid hormone receptors or their DNA or T3 binding activity, suggesting that the function of thyroid hormone receptors could be markedly disturbed in both tumor and peritumoral cells. In summary, we show that ccRCC is characterized by the overexpression of E2F1, which is likely a result of a deregulated control of T3-dependent molecular processes.