Leptin, the first discovered adipokine, has been connected to various physiological and pathophysiological processes, including cancerogenesis. Increasing evidence confirms its influence on prostate cancer cells. However, studies on the effects of leptin on the proliferation and apoptosis of the androgen-sensitive LNCaP line of prostate cancer cells brought conflicting results. Therefore, we performed studies on the effects of high LEP concentration (1 × 10⁻⁶ M) on gene expression profile, change of selected signaling pathways, proliferation and apoptosis of LNCaP cells. RTCA (real-time cell analyzer) revealed inhibitory effect of LEP on cell proliferation, but lower LEP concentrations (10⁻⁸ and 10⁻¹⁰ M) did not affect cell division. Moreover, flow cytometry with a specific antibody for Cleaved PARP-1, an apoptosis marker, confirmed the activation of apoptosis in leptin-exposed LNCaP line of prostate cancer cells. Within 24 h LEP (10⁻⁶ M) increases expression of 297 genes and decreases expression of 119 genes. Differentially expressed genes (DEGs) were subjected to functional annotation and clusterization using the DAVID bioinformatics tools. Most ontological groups are associated with proliferation and apoptosis (seven groups), immune response (six) and extracellular matrix (two). These results were confirmed by the Gene Set Enrichment Analysis (GSEA). The leptin’s effect on apoptosis stimulation was also confirmed using Pathview library. These results were also confirmed by qPCR method. The results of Western Blot analysis (exposure to LEP 10 min, 1, 2, 4 and 24 h) suggest (after 24 h) decrease of p38 MAPK, p44-42 mitogen-activated protein kinase and Bcl-2 phosphorylated at threonine 56. Moreover, exposure of LNCaP cells to LEP significantly stimulates the secretion of matrix metallopeptidase 7 (MMP7). Obtained results suggest activation of apoptotic processes in LNCaP cells cultured at high LEP concentration. At the same time, this activation is accompanied by inhibition of proliferation of the tested cells.

Novel molecular targets are being searched to aid in prostate cancer diagnosis and therapy. Recently, ZFP91 zinc finger protein has been found to be upregulated in prostate cancer cell lines. It is a potentially important oncogenic protein; however only limited data regarding its biological function and expression patterns are available. To date, ZFP91 has been shown to be a key factor in activation of noncanonical NF-κB signaling pathway as well as to be involved in HIF-1α signaling in cancer cells. The present study aimed to characterize ZFP91 expression in prostate cancer specimens. Furthermore, since our earlier reports showed discrepancies between ZFP91 mRNA and protein levels, we studied this interrelationship in LNCaP and PC-3 prostate cancer cell lines using siRNA mediated knockdown. QPCR analysis revealed marked upregulation of ZFP91 mRNA in the majority of prostate cancer specimens. Transfection of prostate cancer cells with ZFP91 siRNA resulted in a 10-fold decrease in mRNA levels. On a protein level, however, no inhibitory effect was observed over the time of the cell culture. We conclude that ZFP91 is overexpressed in prostate cancer and that potential accumulation of the ZFP91 protein in studied cells may be of importance in prostate cancer biology.

In search for novel molecular targets in benign prostate hyperplasia (BPH), a PCR Array based screening of 84 genes was performed. Of those, expression of ZFP91 (ZFP91 zinc finger protein) was notably upregulated. Limited data concerning the function of ZFP91 product show that it is a potential transcription factor upregulated in human acute myelogenous leukemia and most recently found to be the non-canonical NF-κB pathway regulator. In order to test this finding on a larger number of samples, prostate specimens were obtained from patients undergoing adenomectomy for BPH (n = 21), and as a control, from patients undergoing radical cystectomy for bladder cancer (prostates unchanged pathologically, n = 18). Similar studies were performed on cultured human prostate cancer cell lines: LNCaP, DU145, 22Rv1, PC-3; as well as normal prostate epithelial cells—PrEC. Methods employed included: Human Obesity PCR Array (Qiagen), QPCR and Western blotting. QPCR studies confirmed significant overexpression of ZFP91 in BPH samples. On a protein level, however, comparison between normal and BPH prostates revealed insignificant differences. As for prostate cell lines examined, all expressed ZFP91 mRNA. Western blotting analysis showed markedly higher protein levels of ZFP91 in all cancer cell lines in comparison with normal (PrEC) cells. In conclusion, the upregulated ZFP91 mRNA in BPH, not accompanied by parallel changes in ZFP91 protein levels, together with ZFP91 protein abundance in prostate cancer cell lines suggest ZFP91 involvement in these prostate diseases.

Studies on expression of orexins (OXs) and their receptors in human prostate gland and human prostatic cell lines are scanty and their results contradictory. Regarding this, we carefully reinvestigated this problem on human prostatic cell lines. Expression of preproorexin (ppOX) (6 primer pairs), and orexin receptors 1 and 2 (OXR1, OXR2) (4 and 2 primer pairs, respectively) was assessed by conventional PCR and QPCR in human normal (PrEC, PrSc, PrSmC) and prostate carcinoma (Du145, LNCaP, and PC3) cell lines. We designed intron spanning primers and also we applied primers from earlier publications and commercially available ones. With the designed primer pairs, in all studied cell lines we failed to demonstrate expression of ppOX, OXR1 and OXR2 genes at the mRNA level, while reaction products were observed in control tissues (human placenta and adrenals). Primers applied in earlier studies did not form amplification products specific for preproorexin or orexin 1 receptor. Some commercially available primers for orexin receptor 1 produced false positive results. We found no evidence for the presence of preproorexin-orexin receptors system genes' mRNAs in human prostate cell lines. The reported premises for these genes’ expression in prostate and prostatic cell lines may have arisen either from the presence of non-prostate cells included in the samples or from faulty PCR settings.

Zinc finger protein 91 (ZFP91) gene has been recently acknowledged to possess oncogenic properties. To date, its expression has been examined only in a handful of human organs and cancer types. The aim of the present study was to characterize, for the first time, the ZFP91 expression pattern in a range of human tissues and cancer types. ZFP91 mRNA expression was examined using Cancer Survey cDNA sets. Utilized cDNA samples represented 15 human organs and 17 cancer types. ZFP91 mRNA expression was the highest in the testes and lymph nodes. It was downregulated in testis cancer, lymphoma and thyroid cancer, and upregulated in prostate cancer. Among the analyzed cancer types, ZFP91 expression was markedly elevated in sarcomas and melanoma. On a protein level, a large‑scale reverse phase protein array was employed providing samples from 11 organ types and from cancers derived from these organs. ZFP91 protein expression was revealed to be generally stable across the tested samples and was only moderately elevated in breast, ovarian and pancreatic cancers. To the best of our knowledge, this is the first study to thoroughly analyze the ZFP91 expression pattern in human tissues and cancers. The obtained results provide the foundation for further work aiming to reveal its full biological significance.

Urachal carcinoma is a rare malignancy with poor prognosis due to late presentation of the disease and its aggressiveness. Surgery remains the mainstay of therapy even in cases of disease recurrence. To the best of our knowledge, this is the first report of salvage surgery in the case of urachal carcinoma with liver metastasis. The patient was a young woman who suffered from locally advanced urachal carcinoma treated with en-bloc cystectomy, hysterectomy with bilateral adnexectomy, partial resection of the sigmoid colon, and partial resection of the rectus abdominis muscle with the fascia, skin, and umbilicus. Adjuvant chemotherapy with paclitaxel and carboplatin was applied. Two years after the treatment, she was diagnosed with a single liver metastasis and a local pelvic recurrence. In a two-step operation, the patient underwent right hemihepatectomy as well as resection of pelvic recurrence site and adjuvant chemotherapy with gemcitabine. Due to the disease progression, a complete resection of the lesions was not achieved and the response to chemotherapy was poor. The patient died of the disease after a year. Surgery is the first line of treatment for urachal carcinoma and should be always considered as an option in cases of disease recurrence. Radical initial surgical management, close patient surveillance, and prompt treatment of disease relapse may all contribute to prolonging patient’s survival.