Key targets of hormonal treatment of prostate cancer. Part 1: the androgen receptor and steroidogenic pathways

OBJECTIVE

Knowledge of the molecular and cellular changes that occur during the transition of hormone‐naïve to castration‐resistant prostate cancer (CRPC) is increasing rapidly. This might provide a window of opportunity for (future) drug development, and for treating patients with these potential devastating states of disease. The objective of this review is to provide an understanding of the mechanisms that prostate cancer cells use to bypass androgen‐deprived conditions.

METHODS

We searched PubMed for experimental and clinical studies that describe the molecular changes that lead to CRPC.

RESULTS

CRPC remains dependent on a functional androgen receptor (AR), AR‐mediated processes, and on the availability of intraprostatic intracellular androgens. CRPCs might acquire different (molecular) mechanisms that enable them to use intracellular androgens more efficiently (AR amplification, AR protein overexpression, AR hypersensitivity), use alternative splice variants of the AR protein to mediate androgen‐independent AR functioning, and have altered co‐activator and co‐repressor gene and protein expression. Furthermore, CRPCs might have the ability to synthesise androgens de novo from available precursors through a renewed and up‐regulated synthesis of steroid‐hormone converting enzymes. Blocking of enzymes key to de novo androgen synthesis could be an alternative means to treat patients with advanced and/or metastatic disease.

CONCLUSION

In CRPC, prostate cancer cells still rely on intracellular androgens and on an active AR for growth and survival. CRPCs have gained mechanisms that enable them to use steroids from the circulation more efficiently through altered gene expression, and through a renewed and up‐regulated synthesis of steroid hormone‐converting enzymes. Additionally, CRPCs might synthesise AR isoforms that enable AR mediated processes independent from available androgens.     

Advanced Prostate Cancer with ATM Loss: PARP and ATR Inhibitors

BackgroundDeleterious ATM alterations are found in metastatic prostate cancer (PC); PARP inhibition has antitumour activity against this subset, but only some ATM loss PCs respond.ObjectiveTo characterise ATM-deficient lethal PC and to study synthetic lethal therapeutic strategies for this subset.Design, setting, and participantsWe studied advanced PC biopsies using validated immunohistochemical (IHC) and next-generation sequencing (NGS) assays. In vitro cell line models modified using CRISPR-Cas9 to impair ATM function were generated and used in drug-sensitivity and functional assays, with validation in a patient-derived model.Outcome measurements and statistical analysisATM expression by IHC was correlated with clinical outcome using Kaplan-Meier curves and log-rank test; sensitivity to different drug combinations was assessed in the preclinical models.Results and limitationsOverall, we detected ATM IHC loss in 68/631 (11%) PC patients in at least one biopsy, with synchronous and metachronous intrapatient heterogeneity; 46/71 (65%) biopsies with ATM loss had ATM mutations or deletions by NGS. ATM IHC loss was not associated with worse outcome from advanced disease, but ATM loss was associated with increased genomic instability (NtAI:number of subchromosomal regions with allelic imbalance extending to the telomere, p = 0.005; large-scale transitions, p = 0.05). In vitro, ATM loss PC models were sensitive to ATR inhibition, but had variable sensitivity to PARP inhibition; superior antitumour activity was seen with combined PARP and ATR inhibition in these models.ConclusionsATM loss in PC is not always detected by targeted NGS, associates with genomic instability, and is most sensitive to combined ATR and PARP inhibition.Patient summaryOf aggressive prostate cancers, 10% lose the DNA repair gene ATM; this loss may identify a distinct prostate cancer subtype that is most sensitive to the combination of oral drugs targeting PARP and ATR.     

Humoral response after SARS-CoV-2 mRNA vaccination in patients with prostate cancer using steroids

ObjectivesThe effect of concomitant steroid use on the antibody response to a SARS-CoV-2 vaccine in patients with prostate cancer (PC) remains unknown. We aimed to evaluate the rates of antispike immunoglobulin G (IgG) antibody response to the BNT162b2 mRNA vaccine in patients with PC using steroids.MethodsThis cross-sectional study conducted from June 21, 2021 to January 5, 2022 included 215 patients with PC who received the second dose of the BNT162b2 mRNA vaccine at least 7 days before the measurement of titers of IgG antibodies against the receptor-binding domain of SARS-CoV-2 spike (S) protein. We compared the rate of anti-SARS-CoV-2 S IgG ≥15 U/mL between patients with or without concomitant steroid use.ResultsOf 215, we identified 33 patients who had concomitant steroid use. Of these, 12 and 21 patients were metastatic castration-sensitive PC and castration-resistant PC (CRPC), respectively. Patients with concomitant steroid use had a significantly lower rate of antibody titer ≥15 U/mL than those without steroid use (82% vs. 95%, P = 0.021). Patients with CRPC with concomitant steroid use (n =21) also had a lower rate of antibody titer ≥15 U/mL (71%) than those without steroid use (93%, P = 0.051), although this was not statistically different. Increased number of systemic treatments administered after diagnosis of CRPC (3 lines or more) were significantly associated with antibody titers <15 U/mL (97% vs. 77%, P <0.001).ConclusionThe humoral response to the BNT162b2 mRNA vaccine was significantly lower in patients with concomitant steroid use. Anti-SARS-CoV-2 S antibody titers were affected by CRPC status, the accumulation of post-CRPC treatments, and steroid use.     

Overexpression of B7-H3 in CD133 colorectal cancer cells is associated with cancer progression and survival in human patients

Cancer stem–like cells are enriched in CD133-positive (CD133⁺) colorectal cancer (CRC) cells. To date, the biological significance of CD133 expression in cancer stem–like cells is still unknown. B7-H3, a costimulatory molecule, plays a pivotal role in tumor immune escape by inhibiting the functions of T cells. To identify a new marker to predict the tumor grade of CRC, we analyzed the expression of B7-H3 and CD133 in colorectal tumor samples, and their clinical significance was determined. By using a series of techniques including pathologic tissue microarray technology, immunohistochemistry, and immunofluorescent staining, we found B7-H3 was expressed in 56.73% of the CRC cases (59/104) sampled; CD133 was detected in 26.92% of the CRC cases (28/104) sampled. Further analysis indicated that 22 of these CD133⁺ samples expressed B7-H3. We also found coexpression of CD133 and B7-H3 in tumor tissue samples (r = 0.321, P < 0.01). Moreover, in contrast to individual CD133 or B7-H3 expression, the coexpression of B7-H3 and CD133 was evidently associated with the depth of tumor invasion, lymphatic metastasis, distant metastasis, and Dukes' stage, suggesting it is a valuable biomarker for the progression of CRC. Indeed, the patients with coexpression of B7-H3 and CD133 had a poorer survival than the other patients (P < 0.05). In summary, our results reveal that B7-H3 was aberrantly expressed in CD133⁺ CRC cells, and the expression level was closely associated with tumor progression.     

The role of the prostate cancer gene 3 urine test in addition to serum prostate-specific antigen level in prostate cancer screening among breast cancer,early-onset gene mutation carriers

ObjectiveTo evaluate the additive value of the prostate cancer gene 3 (PCA3) urine test to serum prostate-specific antigen (PSA) in prostate cancer (PC) screening among breast cancer, early-onset gene (BRCA) mutation carriers. This study was performed among the Dutch participants of IMPACT, a large international study on the effectiveness of PSA screening among BRCA mutation carriers.Materials and methodsUrinary PCA3 was measured in 191 BRCA1 mutation carriers, 75 BRCA2 mutation carriers, and 308 noncarriers. The physicians and participants were blinded for the results. Serum PSA level≥3.0 ng/ml was used to indicate prostate biopsies. PCA3 was evaluated (1) as an independent indicator for prostate biopsies and (2) as an indicator for prostate biopsies among men with an elevated PSA level. PC detected up to the 2-year screening was used as gold standard as end-of-study biopsies were not performed.ResultsOverall, 23 PCs were diagnosed, 20 of which were in men who had an elevated PSA level in the initial screening round. (1) PCA3, successfully determined in 552 participants, was elevated in 188 (cutoff≥25; 34%) or 134 (cutoff≥35; 24%) participants, including 2 of the 3 PCs missed by PSA. PCA3 would have added 157 (≥25; 28%) or 109 (≥35; 20%) biopsy sessions to screening with PSA only. (2) Elevated PCA3 as a requirement for biopsies in addition to PSA would have saved 37 (cutoff≥25) or 43 (cutoff≥35) of the 68 biopsy sessions, and 7 or 11 PCs would have been missed, respectively, including multiple high-risk PCs. So far, PCA3 performed best among BRCA2 mutation carriers, but the numbers are still small. Because PCA3 was not used to indicate prostate biopsies, its true diagnostic value cannot be calculated.ConclusionsThe results do not provide evidence for PCA3 as a useful additional indicator of prostate biopsies in BRCA mutation carriers, as many participants had an elevated PCA3 in the absence of PC. This must be interpreted with caution because PCA3 was not used to indicate biopsies. Many participants diagnosed with PC had low PCA3, making it invalid as a restrictive marker for prostate biopsies in men with elevated PSA levels.     

Novel second-generation rexinoid induces growth arrest and reduces cancer cell stemness in human neuroblastoma patient-derived xenografts

IntroductionThe poor therapeutic efficacy seen with current treatments for neuroblastoma may be attributed to stem cell-like cancer cells (SCLCCs), a subpopulation of cancer cells associated with poor prognosis and disease recurrence. Retinoic acid (RA) is a differentiating agent used as maintenance therapy for high-risk neuroblastoma but nearly half of children treated with RA relapse. We hypothesized that 6-Methyl-UAB30 (6-Me), a second-generation rexinoid recently developed with a favorable toxicity profile compared to RA, would reduce cancer cell stemness in human neuroblastoma patient-derived xenografts (PDXs).MethodsCells from three neuroblastoma PDXs were treated with 6-Me and proliferation, viability, motility, and cell-cycle progression were assessed. CD133 expression, sphere formation, and mRNA abundance of stemness and differentiation markers were evaluated using flow cytometry, in vitro extreme limiting dilution analysis, and real-time PCR, respectively.ResultsTreatment with 6-Me decreased proliferation, viability, and motility, and induced cell-cycle arrest and differentiation in all three neuroblastoma PDXs. In addition, 6-Me treatment led to decreased CD133 expression, decreased sphere-forming ability, and decreased mRNA abundance of Oct4, Nanog, and Sox2, indicating decreased cancer cell stemness.Conclusions6-Me decreased oncogenicity and reduced cancer cell stemness of neuroblastoma PDXs, warranting further exploration of 6-Me as potential novel therapy for neuroblastoma.     

Targeted Next-generation Sequencing of Advanced Prostate Cancer Identifies Potential Therapeutic Targets and Disease Heterogeneity

Background

Most personalized cancer care strategies involving DNA sequencing are highly reliant on acquiring sufficient fresh or frozen tissue. It has been challenging to comprehensively evaluate the genome of advanced prostate cancer (PCa) because of limited access to metastatic tissue.

Objective

To demonstrate the feasibility of a novel next-generation sequencing (NGS)–based platform that can be used with archival formalin-fixed paraffin-embedded (FFPE) biopsy tissue to evaluate the spectrum of DNA alterations seen in advanced PCa.

Design, setting, and participants

FFPE samples (including archival prostatectomies and prostate needle biopsies) were obtained from 45 patients representing the spectrum of disease: localized PCa, metastatic hormone-naive PCa, and metastatic castration-resistant PCa (CRPC). We also assessed paired primaries and metastases to understand disease heterogeneity and disease progression.

Intervention

At least 50 ng of tumor DNA was extracted from FFPE samples and used for hybridization capture and NGS using the Illumina HiSeq 2000 platform.

Outcome measurements and statistical analysis

A total of 3320 exons of 182 cancer-associated genes and 37 introns of 14 commonly rearranged genes were evaluated for genomic alterations.

Results and limitations

We obtained an average sequencing depth of >900X. Overall, 44% of CRPCs harbored genomic alterations involving the androgen receptor gene (AR), including AR copy number gain (24% of CRPCs) or AR point mutation (20% of CRPCs). Other recurrent mutations included transmembrane protease, serine 2 gene (TMPRSS2):v-ets erythroblastosis virus E26 oncogene homolog (avian) gene (ERG) fusion (44%); phosphatase and tensin homolog gene (PTEN) loss (44%); tumor protein p53 gene (TP53) mutation (40%); retinoblastoma gene (RB) loss (28%); v-myc myelocytomatosis viral oncogene homolog (avian) gene (MYC) gain (12%); and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α gene (PIK3CA) mutation (4%). There was a high incidence of genomic alterations involving key genes important for DNA repair, including breast cancer 2, early onset gene (BRCA2) loss (12%) and ataxia telangiectasia mutated gene (ATM) mutations (8%); these alterations are potentially targetable with poly(adenosine diphosphate-ribose)polymerase inhibitors. A novel and actionable rearrangement involving the v-raf murine sarcoma viral oncogene homolog B1 gene (BRAF) was also detected.

Conclusions

This first-in-principle study demonstrates the feasibility of performing in-depth DNA analyses using FFPE tissue and brings new insight toward understanding the genomic landscape within advanced PCa.     

膜联蛋白7在转移性激素敏感前列腺癌原发灶组织中的表达及其意义

目的检测膜联蛋白7(ANXA7)在转移性激素敏感前列腺癌(HSPC)原发灶组织中的表达,探讨对其预后意义。方法取转移性HSPC原发灶组织106例,免疫组化检测标本ANXA7蛋白表达,分析其表达与常见临床病理指标和疾病无进展生存时间(PFS)及总生存时间(OS)的相关性。对照组为前列腺增生20例,去势抵抗性前列腺癌(CRPC)22例。结果转移性HSPC原发灶组织ANXA7阳性表达率为50/106(47.2%),前列腺增生组织ANXA7全部阳性表达,CRPC组织为3/22(13.6%),差异比较均有显著统计学意义(P0.05)。ANXA7表达减少与T分期、N分期级别高及Gleason评分高相关,生存分析显示ANXA7表达减少与较短的PFS和OS相关,ANXA7阳性和阴性表达者PFS中位值分别为24.4月和15.5月,OS中位值分别为56.4月和36.1月。结论 ANXA7在转移性HSPC原发灶组织中表达减少,其参与疾病进展过程,表达异常往往与患者不良预后相关。     

Predictors for response to intermittent androgen deprivation (IAD) in prostate cancer cases with biochemical progression after surgery

ObjectiveTo define characteristics of the first cycle of intermittent androgen deprivation (IAD) that would predict for outcomes in a long term follow-up.Material and methodsIn 1996 we started a prospective study of IAD for the treatment of biochemical progression (BP) after radical prostatectomy (RP) for prostate cancer (PC). The end-points of the trial were time to clinical progression (CP) and time to castration resistance PC (CRPC). Eighty-four cases were included in the study. In all cases, after an initial induction period, an acceptable nadir to switch from on-to-off-phase of IAD was considered to be a serum PSA < 1.0 ng/ml.MeasurementsAs possible predictors for time to CP and CRPC, we analyzed pretreatment parameters such as age, Gleason Score, serum PSA, testosterone, chromogranina A (CgA) levels, and characteristics from the first cycle of IAD.ResultsMean follow-up during IAD was 88.6 ± 16.7 months; 29.7% of patients developed CRPC and 14.2% of cases showed a CP with a mean time of 88.4 ± 14.3 months and 106.5 ± 20.6 months, respectively. At univariate and multivariate analysis, the PSA nadir during the first on-phase period and the first off-phase interval resulted in significant and independent predictors (P < 0.001) of the time to CRPC and CP. In particular for cases with a PSA nadir > 0.4 ng/ml and for those with an off-phase interval ≤ 24 weeks, the risk of CRPC and CP during IAD was 2.7–2.5 and 3.0–3.1 times that for patients with a PSA nadir ≤ 0.1 ng/ml and with an off-phase interval > 48 weeks, respectively.ConclusionsCases with BP after RP selected to IAD that show at the first cycle a PSA nadir ≤ 0.1 ng/ml and a off-phase interval ≥ 48 weeks may identify candidates who will experience better response to IAD treatments and delayed CP or CRPC development.     

Factores clínicos determinantes para la realización de pruebas de imagen en cáncer de próstata resistente a la castración no metastásico en la práctica clínica: resultados del estudio IDENTIFICA

IntroductionThe aim of the study was to describe the clinical drivers that lead physicians to perform imaging tests in search of metastasis in non-metastasic castration prostate resistant cancer (nmCRPC) patients.MethodsObservational, cross-sectional study conducted at the Departments of Urology of 38 Spanish hospitals. The study included 188 patients diagnosed with nmCRPC who underwent an imaging test for the assessment of metástasis. In one study visit, physicians were requested to specify the clinical factors that led them to perform these tests. The results of the imaging tests and the clinical characteristics of the patients since the time of prostate cancer (PC) diagnosis, were reported. Regression analyses were used to determine predictors of imaging test results.ResultsProstate-specific antigen (PSA) level was the most important driver to order imaging tests (57.1%), followed by regular follow-up (16.5%) and PSA doubling time (PSADT) (12.0%). Although these drivers were not associated to detection of metastasis, patients with PSA levels ≥20 ng/mL had a greater risk of metastasis than patients with PSA levels < 4ng/mL (P=.004) and CRPC patients diagnosed with metastasis (mCRPC) had higher median PSA levels (20.9; interquartile range [IQR]: 6.7-38.6) than nmCRPC (9.1; IQR: 5.0-18.0) (P=.005). Sixty-six percent of the patients did not undergo any imaging test after CRPC diagnosis until the study visit (10.6, IQR: 4.0-19.5 months). Curative-intent treatment at PC diagnosis and Gleason score predicted longer time from PC to CRPC diagnosis.ConclusionsPhysicians based their decisions to order imaging tests for metastasis detection in nmCRPC patients mainly on PSA and PSA kinetics, including the regular follow-up stated by guideline recommendations.     

Clinical Significance of B7-H1 and B7-1 Expressions in Pancreatic Carcinoma

Background  

Cancer cells develop mechanisms to evade immune cells and achieve progression. Aberrant B7-H1 and B7-1 expressions may help pancreatic carcinoma (PC) cells escape immune attack; these molecules can be considered as prognostic markers for patients with PC who have undergone radical resection.     

Human amniotic fluid stem cells attenuate cholangiocyte apoptosis in a bile duct injury model of liver ductal organoids

PurposeBiliary atresia (BA) is a fibro-obliterative cholangiopathy that involves both extrahepatic and intrahepatic bile ducts in infants. Cholangiocyte apoptosis has an influence on the fibrogenesis process of bile ducts and the progression of liver fibrosis in BA. Human amniotic fluid stem cells (hAFSCs) are multipotent cells that have ability to inhibit cell apoptosis. We aimed to investigate whether hAFSCs have the potential to attenuate cholangiocyte apoptosis and injury induced fibrogenic response in our ex vivo bile duct injury model of liver ductal organoids.MethodsThe anti-apoptotic effect of hAFSCs was tested in the acetaminophen-induced injury model of neonatal mouse liver ductal organoids (AUP #42681) by using direct and indirect co-culture systems. Cell apoptosis and proliferation were evaluated by immunofluorescent staining. Expression of fibrogenic cytokines was analyzed by RT-qPCR. Data were compared using one-way ANOVA with post hoc test.ResultsIn our injury model, liver ductal organoids that were treated with hAFSCs in both direct and indirect co-culture systems had a significantly smaller number of apoptotic cholangiocytes and decreased expression of fibrogenic cytokines, transforming growth factor beta-1 (TGF-β1) and platelet-derived growth factor-BB (PDGF-BB). Moreover, hAFSCs increased cholangiocyte proliferation in injured organoids.ConclusionhAFSCs have the ability to protect the organoids from injury by decreasing cholangiocyte apoptosis and promoting cholangiocyte proliferation. This protective ability of hAFSCs leads to inhibition of the fibrogenic response in the injured organoids. hAFSCs have high therapeutic potential to attenuate liver fibrogenesis in cholangiopathic diseases such as BA.     

Creation of a primary tumor tissue expression biomarker-augmented prognostic model for patients with metastatic renal cell carcinoma

BackgroundClinical and pathological factors alone have limited prognostic ability in patients with metastatic clear cell renal cell carcinoma (ccRCC). Bim, a downstream pro-apoptotic molecule in the PD-1 signaling pathway, has recently been associated with survival in other malignancies. We sought to determine if tissue biomarkers including Bim, added to a previously reported clinical metastases score, improved prediction of cancer-specific survival (CSS) for patients with metastatic ccRCC.MethodsPatients with metastatic ccRCC who underwent nephrectomy between 1990 and 2004 were identified using our institutional registry. Sections from paraffin-embedded primary tumor tissue blocks were used for immunohistochemistry staining for Bim, PD-1, B7-H1 (PD-L1), B7-H3, CA-IX, IMP3, Ki67, and survivin. Biomarkers that were significantly associated with CSS after adjusting for the metastases score were used to develop a biomarker-specific multivariable model using a bootstrap resampling approach and forward selection. Predictive ability was summarized using a bootstrap-corrected c-index.ResultsThe cohort included 602 patients: 192 (32%) with metastases at diagnosis and 410 (68%) who developed metastases after nephrectomy. Median follow-up was 9.6 years (IQR 4.2–12.8), during which 504 patients died of RCC. Bim, IMP3, Ki67, and survivin expression were significantly associated with CSS after adjusting for the metastases score, and were eligible for biomarker-specific model inclusion. After variable selection, high Bim (hazard ratio [HR] = 1.44; 95% confidence interval [CI] 1.16–1.78; P <0.001), high survivin (HR = 1.35; 95% CI 1.08–1.68; P = 0.008), and the metastases score (HR = 1.13 per 1 point; 95% CI 1.10–1.16; P <0.001) were retained in the final multivariable model (c-index = 0.69).ConclusionWe created a prognostic model combining the clinical metastases score and 2 primary tumor tissue expression biomarkers, Bim and survivin, for patients with metastatic renal cell carcinoma who underwent nephrectomy.