The Identification of Small Molecule Inhibitors That Reduce Invasion and Metastasis of Aggressive Cancers.

Transformed epithelial cells can activate programs of epithelial plasticity and switch from a sessile, epithelial phenotype to a motile, mesenchymal phenotype. This process is linked to the acquisition of an invasive phenotype and the formation of distant metastases. The development of compounds that block the acquisition of an invasive phenotype or revert the invasive mesenchymal phenotype into a more differentiated epithelial phenotype represent a promising anticancer strategy. In a high-throughput assay based on E-cadherin (re)induction and the inhibition of tumor cell invasion, 44,475 low molecular weight (LMW) compounds were screened. The screening resulted in the identification of candidate compounds from the PROAM02 class. Selected LMW compounds activated E-cadherin promoter activity and inhibited cancer cell invasion in multiple metastatic human cancer cell lines. The intraperitoneal administration of selected LMW compounds reduced the tumor burden in human prostate and breast cancer in vivo mouse models. Moreover, selected LMW compounds decreased the intra-bone growth of xenografted human prostate cancer cells. This study describes the identification of the PROAM02 class of small molecules that can be exploited to reduce cancer cell invasion and metastases. Further clinical evaluation of selected candidate inhibitors is warranted to address their safety, bioavailability and antitumor efficacy in the management of patients with aggressive cancers.

Urine cell-based DNA methylation classifier for monitoring bladder cancer.

Background: Current standard methods used to detect and monitor bladder cancer (BC) are invasive or have low sensitivity. This study aimed to develop a urine methylation biomarker classifier for BC monitoring and validate this classifier in patients in follow-up for bladder cancer (PFBC). Methods: Voided urine samples (N = 725) from BC patients, controls, and PFBC were prospectively collected in four centers. Finally, 626 urine samples were available for analysis. DNA was extracted from the urinary cells and bisulfite modificated, and methylation status was analyzed using pyrosequencing. Cytology was available from a subset of patients (N = 399). In the discovery phase, seven selected genes from the literature (CDH13, CFTR, NID2, SALL3, TMEFF2, TWIST1, and VIM2) were studied in 111 BC and 57 control samples. This training set was used to develop a gene classifier by logistic regression and was validated in 458 PFBC samples (173 with recurrence). Results: A three-gene methylation classifier containing CFTR, SALL3, and TWIST1 was developed in the training set (AUC 0.874). The classifier achieved an AUC of 0.741 in the validation series. Cytology results were available for 308 samples from the validation set. Cytology achieved AUC 0.696 whereas the classifier in this subset of patients reached an AUC 0.768. Combining the methylation classifier with cytology results achieved an AUC 0.86 in the validation set, with a sensitivity of 96%, a specificity of 40%, and a positive and negative predictive value of 56 and 92%, respectively. Conclusions: The combination of the three-gene methylation classifier and cytology results has high sensitivity and high negative predictive value in a real clinical scenario (PFBC). The proposed classifier is a useful test for predicting BC recurrence and decrease the number of cystoscopies in the follow-up of BC patients. If only patients with a positive combined classifier result would be cystoscopied, 36% of all cystoscopies can be prevented.

The role of HOXC6 in prostate cancer development.

BACKGROUND: Homeobox (HOX) genes, which are involved in organ development and homeostasis, have been shown to be involved in normal prostate- and PCa development. In this study, we investigate the expression levels of the HOX A-D genes in PCa. The functional relevance and potential of HOX gene as biomarkers are explored. METHODS: We evaluated HOX gene expression in prostate tissues of different grade and stage and related the outcome to clinical parameters. We analyzed AR regulation and function of HOXC6 in PCa cell lines. We developed a urine-based HOXC6 mRNA assay for diagnostic purposes. RESULTS: HOXC6 was one of the most upregulated HOX genes in all primary, metastasized, and castration-resistant PCa. HOXC6 upregulation was specific to the epithelial component of PCa, and HOXC6 was shown to be involved in epithelial cell proliferation. HOXC6 expression was not influenced by androgens nor by treatments targeting the AR signaling pathway. HOXC6 expression was not related to a prognosis after radical prostatectomy, that is, biochemical or local recurrence. We successfully developed an assay for HOXC6 mRNA detection in urine and confirmed that HOXC6 levels are higher in PCa patients. CONCLUSIONS: HOXC6 has a role in all PCa stages, particularly in PCa cell proliferation. Due to its stable expression, HOXC6 is a novel candidate biomarker for PCa not only in early detection but also for monitoring of progression or response to therapy.

Dutasteride and enzalutamide synergistically suppress prostate tumor cell proliferation.

PURPOSE: Dihydrotestosterone is the main active androgen in the prostate and it has a role in prostate cancer progression. After androgen deprivation therapy androgen receptor signaling is still active in tumor cells. Persistent intratumor steroidogenesis and androgen receptor changes are responsible for this continued activity, which influences the efficacy of prostate cancer treatment. We hypothesized that combining a 5α-reductase inhibitor and an antiandrogen would block intratumor androgen synthesis and androgen receptor protein activity. Thus, it would act synergistically to reduce tumor cell proliferation. MATERIALS AND METHODS: The expression level of 5α-reductase and androgen receptor in endocrine therapy naïve prostate cancer and castration resistant prostate cancer tissues, and cell line models was determined by microarray and quantitative polymerase chain reaction analysis. Intracellular androgen was measured with radioimmunoassay. Tumor cell proliferation was determined using coloric MTT assay. The synergistic effects of combination treatments on tumor cell proliferation were calculated using the Chou-Talalay equation. RESULTS: In all prostate cancer cases 5α-reductase-1 and 3 were up-regulated. Androgen receptor was up-regulated in metastatic prostate cancer and castration resistant prostate cancer cases. The 5α-reductase inhibitor dutasteride effectively decreased dihydrotestosterone production in prostate cancer and castration resistant prostate cancer cell lines. Furthermore, dutasteride combined with the novel antiandrogen enzalutamide synergistically suppressed endocrine therapy naïve prostate cancer and castration resistant prostate cancer cell proliferation. CONCLUSIONS: In this study the combination of a 5α-reductase inhibitor and (novel) antiandrogens synergistically inhibited tumor cell proliferation. These findings support clinical studies of combinations of a 5α-reductase inhibitor and (novel) antiandrogens as first line treatment of prostate cancer and castration resistant prostate cancer.