St typical cancer in non-smoking men worldwide and the third reason for cancer-related death just after lung and colorectal cancers (http:/gco.iarc.fr/). Androgen deprivation CDK2 custom synthesis therapy (ADT) continues to be the primary treatment option for sophisticated PCa although most patients will ultimately develop castration-resistant prostate cancer (CRPC) [1,2]. CRPC patients are frequently treated with novel hormonal agents (NHAs), for instance Abiraterone Acetate (AA) and Enzalutamide (Enz) [3,4]. AA blocks testosterone production by way of 17–hydroxylase enzyme (CYP17A1) inhibition . In contrast, Enz binds to the androgen receptor (AR) ligand binding domain (LBD) decreasing its nuclear translocation and consequently AR transcriptional activation . On the other hand, around 15 of individuals are initially unresponsive to both of those treatments and a lot of more acquire resistance 9 to 15 months later [3,4]. Additionally, individuals that become resistant to AA create cross-resistance to Enz and vice versa, challenging the sequential use of these drugs . Many molecular mechanisms connected to CRPC and AR have already been described: increased testosterone synthesis within the adrenal glands or prostatic tissue, AR overexpression, AR amplification, AR mutations, loss of AR expression by hypermethylation on the AR promoter or expression of AR splice variants (AR-Vs) . These AR-Vs are originated by option splicing of cryptic exons positioned on intron 3 in the AR locus, along with the resulting protein VEGFR1/Flt-1 Source isoforms conserve the N-terminal activation domain but drop the C-terminal LBD acting as an androgen-independent transcription aspect. AR variant 7 (AR-V7) may be the most normally studied variant in PCa, and its detection in circulating tumour cells (CTCs) has been described as a prognostic marker for AA and Enz resistance . Not too long ago, Cato et al. showed that AR-V7 types a heterodimer with AR full-length repressing the expression of relevant tumour-suppressor genes in CRPC cellular models . Additionally, AR-V9 was shown to share a typical 3 terminal cryptic exon with AR-V7 and was recently described to be co-expressed in AA-resistant PCa metastatic patients .Cancers 2021, 13,3 ofThe primary aims of this perform were to generate and to characterize novel CRPC cellular models from androgen sensitive PCa cell lines: (a) ADT-resistant PCa cell lines (R-ADT) selected in the absence of androgens; (b) Concomitant ADT-NHA-resistant PCa cell lines (R-ADT/AA, R-ADT/E, R-ADT/E + A) obtained via the continuous growth within the presence of NHAs and the absence of androgens. We evaluated the proliferation prices and cell cycle, AR expression levels, AR transcriptional activity, functionality (cell migration and invasion) along with the cross-resistance among the various NHA therapies in all new CRPC models. two. Material and Strategies 2.1. Cell Culture Three unique human PCa cell lines had been utilized: LNCaP (androgen-sensitive adenocarcinoma cells derived from supraclavicular lymph node metastasis) and 22RV1 (carcinoma epithelial cell line derived from androgen-dependent CWR22 xenograft after castrationinduced regression and relapse), both bought in the American Type Culture Collection (ATCC, Manassas, VA, USA), and PC-3 (androgen-independent cell line originated from a bone metastasis of prostatic adenocarcinoma), that was kindly supplied by Dr Ignacio Gil Bazo (CIMA, Pamplona, Spain) as CRPC model. All cell lines have been authenticated employing STR in the Laboratory of Genetic Identification (Legal Medicine and Toxicolo.