Preoperative insulin-like growth factor-binding protein-3 (IGFBP-3) blood level predicts gleason sum upgrading

The Potential of Extracellular Matrix- and Integrin Adhesion Complex-Related Molecules for Prostate Cancer Biomarker Discovery

Prostate cancer is among the top five cancer types according to incidence and mortality. One of the main obstacles in prostate cancer management is the inability to foresee its course, which ranges from slow growth throughout years that requires minimum or no intervention to highly aggressive disease that spreads quickly and resists treatment. Therefore, it is not surprising that numerous studies have attempted to find biomarkers of prostate cancer occurrence, risk stratification, therapy response, and patient outcome. However, only a few prostate cancer biomarkers are used in clinics, which shows how difficult it is to find a novel biomarker. Cell adhesion to the extracellular matrix (ECM) through integrins is among the essential processes that govern its fate. Upon activation and ligation, integrins form multi-protein intracellular structures called integrin adhesion complexes (IACs). In this review article, the focus is put on the biomarker potential of the ECM- and IAC-related molecules stemming from both body fluids and prostate cancer tissue. The processes that they are involved in, such as tumor stiffening, bone turnover, and communication via exosomes, and their biomarker potential are also reviewed.

Periprostatic adipose tissue promotes prostate cancer resistance to docetaxel by paracrine IGF-1 upregulation of TUBB2B beta-tubulin isoform

Growing evidence supports the pivotal role played by periprostatic adipose tissue (PPAT) in prostate cancer (PCa) microenvironment. We investigated whether PPAT can affect response to Docetaxel (DCTX) and the mechanisms associated. Conditioned medium was collected from the in vitro differentiated adipocytes isolated from PPAT which was isolated from PCa patients, during radical prostatectomy. Drug efficacy was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide citotoxicity assay. Culture with CM of human PPAT (AdipoCM) promotes DCTX resistance in two different human prostate cancer cell lines (DU145 and PC3) and upregulated the expression of BCL-xL, BCL-2, and TUBB2B. AG1024, a well-known IGF-1 receptor inhibitor, counteracts the decreased response to DCTX observed in presence of AdipoCM and decreased TUBB2B expression, suggesting that a paracrine secretion of IGF-1 by PPAT affect DCTX response of PCa cell. Collectively, our study showed that factors secreted by PPAT elicits DCTX resistance through antiapoptotic proteins and TUBB2B upregulation in androgen independent PCa cell lines. These findings reveal the potential of novel therapeutic strategies targeting adipocyte-released factors and IGF-1 axis to overcome DCTX resistance in patients with PCa.

Optimized Identification of High-Grade Prostate Cancer by Combining Different PSA Molecular Forms and PSA Density in a Deep Learning Model

After skin cancer, prostate cancer (PC) is the most common cancer among men. The gold standard for PC diagnosis is based on the PSA (prostate-specific antigen) test. Based on this preliminary screening, the physician decides whether to proceed with further tests, typically prostate biopsy, to confirm cancer and evaluate its aggressiveness. Nevertheless, the specificity of the PSA test is suboptimal and, as a result, about 75% of men who undergo a prostate biopsy do not have cancer even if they have elevated PSA levels. Overdiagnosis leads to unnecessary overtreatment of prostate cancer with undesirable side effects, such as incontinence, erectile dysfunction, infections, and pain. Here, we used artificial neuronal networks to develop models that can diagnose PC efficiently. The model receives as an input a panel of 4 clinical variables (total PSA, free PSA, p2PSA, and PSA density) plus age. The output of the model is an estimate of the Gleason score of the patient. After training on a dataset of 190 samples and optimization of the variables, the model achieved values of sensitivity as high as 86% and 89% specificity. The efficiency of the method can be improved even further by training the model on larger datasets.

Polyphyllin I inhibits invasion and epithelial-mesenchymal transition via CIP2A/PP2A/ERK signaling in prostate cancer

Polyphyllin I (PPI) is a natural compound extracted from the rhizomes of Paris polyphylla and has been used to treat fevers and headaches in China. In the present study, the antitumor activity of PPI in prostate cancer (PC) cells was evaluated. At low doses, PPI decreased proliferation, invasion and epithelial-mesenchymal transition (EMT) in PC cells. PPI decreased the expression of matrix metalloproteinase 7 (MMP7), an enzyme that is critical for tumor metastasis. PPI also decreased the expression of Snail and vimentin, which are EMT-associated factors. Additionally, PPI suppressed AP-1 transcriptional activity and AP-1 binding to the MMP7 and vimentin promoters. The results demonstrated that PPI downregulated the phosphorylation of extracellular signaling‑related kinase (ERK), which is upstream modulator of AP-1. The results of the present study demonstrated that PPI may inhibit the cancerous inhibitor of protein phosphatase 2A (CIP2A)/protein phosphatase 2A (PP2A)/ERK axis, downregulate the expression of MMP7, vimentin, and Snail, and suppress tumor invasion and EMT. A PC xenograft mouse model was employed and the results revealed that PPI may decrease tumor growth and weight. Additionally, PPI may inhibit proliferating cell nuclear antigen expression and CIP2A/PP2A/ERK signaling pathway in PPI-treated tumors. Therefore, the results of the present study suggest that PPI may suppress the growth, invasion and EMT of PC cells via inhibition of CIP2A/PP2A/ERK signaling axis. As a result, PPI may be a novel target for the treatment of PC.

BMI and serum lipid parameters predict increasing risk and aggressive prostate cancer in Chinese people

OBJECTIVES

To determine if obesity and serum lipid parameters are associated with increased risk and more aggressive prostate cancer in Chinese population.

MATERIALS AND METHODS

We conducted a retrospective cohort analysis including 3102 patients. Kruskal-Wallis test for continuous variables and the chi-squared tests for categorical variables were used for univariate comparison of the differences in patient characteristics across BMI categories between different groups. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for the association between prostate cancer and the various patient characteristics. Multivariable Cox proportional hazards regression was performed to assess the risk of prostate cancer recurrence.

RESULTS

974 consecutive men were diagnosed as prostate cancer and 700 patients subsequently received radical prostatectomy immediately, and 1031 patients were pathologically diagnosed as biopsy negative. The level of low-density-lipoprotein cholesterol (LDL-c) and total cholesterol was significantly higher and the high-density-lipoprotein cholesterol (HDL-c) level is much lower in prostate cancer patients. Patients with low level of HDL-c, who subsequently received radical prostatectomy, had increased risk of high risk disease. In addition, patients with normal weight were less likely to develop a biochemical recurrence. Combined analysis revealed that obese patients had significantly higher rates of PSA recurrence over time than nonobese patients.

CONCLUSIONS

In our study, lipid parameters are supposed to be associated with prostate cancer risk and aggressiveness. Obese men are at increased risk of PSA recurrence after radical prostatectomy.

IGFBP3 and MAPK/ERK signaling mediates melatonin-induced antitumor activity in prostate cancer

Treatment of prostate cancer (PCa), a leading cause of cancer among males, lacks successful strategies especially in advanced, hormone-refractory stages. Some clinical studies have shown an increase in neuroendocrine-like cells parallel to the tumor progression but their exact role is a matter of debate. The prostate is a well-known target for melatonin, which reduces PCa cells proliferation and induces neuroendocrine differentiation. To evaluate the mechanisms underlying the indole effects on neuroendocrine differentiation and its impact on PCa progression, we used a cell culture model (LNCaP) and a murine model (TRAMP). Persistent ERK1/2 activation was found in both, melatonin and androgen-deprived cells. Melatonin blocked nuclear translocation of androgen receptor (AR), thus confirming anti-androgenic actions of the indole. However, using a comparative genome microarray to check the differentially expressed genes in control, melatonin, or androgen-deprived cells, some differences were found, suggesting a more complex role of the indole. By comparing control cells with those treated with melatonin or depleted of androgen, a cluster of 26 differentially expressed genes (±2.5-fold) was found. Kallikreins (KLK)2 and KLK3 (PSA) were dramatically downregulated by both treatments whereas IGFBP3 and IGF1R were up- and downregulated, respectively, in both experimental groups, thus showing a role for IGF in both scenarios. Finally, melatonin prolonged the survival of TRAMP mice by 33% when given at the beginning or at advances stages of the tumor. Serum IGFBP3 was significantly elevated by the indole in early stages of the tumor, confirming in vivo the role of the IGF signaling in the oncostatic action of the indole.

Urotensin II receptor on preoperative biopsy is associated with upstaging and upgrading in prostate cancer

AIM

A higher Gleason score was associated with a lower tumor urotensin II receptor (UTII-R) expression in prostate cancer patients.

METHODS

A retrospective review of formalin-fixed paraffin-embedded tumor tissue derived from those who had prostatectomy and matching biopsy specimens was conducted at six Institutions. UTII-R expression was evaluated on biopsy by immunohistochemistry.

RESULTS

A total of 58 subjects undergoing radical prostatectomy were included. At multivariate analysis, low UTII-R expression was a significant predictor of Gleason upgrading, with an odds ratio of 10.3 (95% CI: 1.55-68.4), and of pathology upstaging, with an odds ratio of 11.1 (95% CI: 1.23-100.48).

CONCLUSIONS

UTII-R expression on biopsy was associated with Gleason upgrading and pathology upstaging in prostate cancer patients.

IGFBP-3 nuclear localization predicts human prostate cancer recurrence

Insulin-like growth factor binding protein-3 (IGFBP-3) is a pro-apoptotic, anti-metastasic, and anti-angiogenic protein. Low serum IGFBP-3 has been associated with risk of more aggressive prostate cancer (PCa). We investigated the impact of nuclear and cytoplasmic IGFBP-3 protein expression levels in PCa by examining their in situ expression across a wide spectrum of primary tumors by immunohistochemical analysis of tissue microarrays. Immunohistochemistry was performed on PCa microarrays constructed from 226 hormone naïve patients who underwent radical prostatectomy. Both cytoplasmic and nuclear IGFBP-3 expressions were scored in a semi-quantitative fashion using an integrated measure of intensity and positivity. The distribution of IGFBP-3 protein expression was examined across the spectrum of epithelial tissues, and its association with standard clinicopathological covariates and tumor recurrence was examined. There was a broad range of IGFBP-3 staining across all histologies examined. Tumor had higher IGFBP-3 cytoplasmic and nuclear staining than benign histologies. For IGFBP-3 nuclear staining, PCa was significantly different than benign prostatic hyperplasia, normal prostate, and prostate intraepithelial neoplasia. As both a continuous and dichotomized variable, higher nuclear IGFBP-3 expression had statistically significant associations with PCa recurrence. The cytoplasmic staining had no significance in any patient subgroup. In patients with low-grade cancer, IGFBP-3 nuclear positivity was a better predictor of recurrence than baseline PSA, tumor margin status, TNM tumor stage, or presence of capsular invasion. High nuclear IGFBP-3 is amongst the strongest predictors of cancer recurrence in patients with low-grade prostate cancers and may therefore play an important role in risk stratification.