Biomarkers of response to advanced prostate cancer therapy

Transcriptome-Wide Association Study Identified Novel Blood Tissue Gene Biomarkers for Prostate Cancer Risk

OBJECTIVE

A number of susceptibility genes in prostate tissue have been identified to be associated with prostate cancer (PCa) risk. However, the reported genes based on assessing prostate tissue could not fully explain PCa genetic susceptibility. It is believed that genes functioning in the immune system may fill in the gap of some missing heritability.

METHODS

To study potential susceptibility genes acting in such pathways, we performed a transcriptome-wide association study (TWAS) of 79,194 PCa cases and 61,112 control of European ancestry by using three sets of gene expression prediction models of blood tissue.

RESULTS

A total of 470 genes were associated at false discovery rates-corrected p-value < 0.05, of which 51 were implicated as likely causal genes based on fine-mapping analysis. Compared with previous literature, 133 novel genes were reported for the first time. Of the identified genes, five (CREB3L4, GSTP1, MAPK3, NKX3-1, and PIK3C2B) were enriched in a PCa signaling pathway, and 128 genes were enriched in five PCa categories. Importantly, 13 genes (SCP2, LMNA, ZNF148, H2AFV, TACC1, FLII, SUPT4H1, CD300LF, MYO9B, COX6B1, CTSA, EP300, and TSPO) showed consistent effect directions for the measured levels in circulating immune cells between PCa cases and controls, and 14 genes (SLC39A1, ZBTB7B, TRIM59, NCEH1, N4BP2, TAGAP, TACC1, TRAF1, AIP, SECTM1, C18orf54, ZNF793, YIF1B, and TSPO) showed consistency for levels in blood exosomes between PCa patients and controls.

CONCLUSION

The identified blood-based candidate susceptibility genes provide further insights into the genetic basis of PCa risk.

Multi-gene risk score for prediction of clinical outcomes in treatment-naïve metastatic castrate-resistant prostate cancer

BACKGROUND

To determine the performance of a multi-gene copy number variation (MG-CNV) risk score in metastatic tissue and plasma biospecimens from treatment-naïve metastatic castration-resistant prostate cancer (mCRPC) patients for prediction of clinical outcomes.

METHODS

The mCRPC tissue and plasma cell-free DNA (cfDNA) biospecimen sequencing results obtained from publicly accessed cohorts in dbGaP, cBioPortal, and an institutional mCRPC cohort were used to develop a MG-CNV risk score derived from gains in AR, MYC, COL22A1, PIK3CA, PIK3CB, NOTCH1 and losses in TMPRSS2, NCOR1, ZBTB16, TP53, NKX3-1 in independent cohorts for determining overall survival (OS), progression-free survival (PFS) to first-line androgen receptor pathway inhibitors (ARPIs). The range of the risk scores for each cohort was dichotomized into "high-risk" and "low-risk" groups and association with OS/PFS determined. Univariate and multivariable Cox proportional hazards regressions were applied for survival analyses (P < .05 for statistical significance).

RESULTS

Of 1137 metastatic tissue-plasma biospecimens across all cohorts, 699/1137 were treatment-naive mCRPC (235/699 metastatic tissue; 464/699 plasma-cfDNA), and 311/1137 were matched tissue-cfDNA pairs. In multivariable analysis, the MG-CNV risk score derived from metastatic tissue or in cfDNA was statistically significantly associated with OS with high score associated with short survival (hazard ratio = 2.65, confidence interval = 1.99 to 3.51; P = 1.35-11) and shorter PFS to ARPIs (median PFS of 7.8 months) compared with 14 months in patients with low-risk score.

CONCLUSIONS

A molecular risk score in treatment-naïve mCRPC state obtained either in metastatic tissue or cfDNA predicts clinical survival outcomes and offers a tumor biology-based tool to design biomarker-based enrichment clinical trials.

Multigene Copy Number Alteration Risk Score Biomarker-Based Enrichment Study Designs in Metastatic Castrate-Resistant Prostate Cancer

PURPOSE

A composite multigene risk score derived from tumor-biology alterations specific to metastatic castrate-resistant prostate cancer (mCRPC) state was evaluated as a classifier to design biomarker-based enrichment clinical trials.

METHODS

A plasma cell-free DNA copy number alteration risk score based on alterations in 24 genes was simulated to develop a biomarker classifier-based clinical trial design enriched for high-risk patients to detect a survival advantage of a novel treatment (hazard ratio of 0.70 with 80% power). We determined the design trade-offs between the number of patients screened and enrolled when varying the type of patients to enrich and the extent of enrichment needed.

RESULTS

For a 2-year overall survival end point in mCRPC state, fully enriching patients with mCRPC having a high-risk score of 3 or more (the 95th percentile of a range of risk scores in patients with mCRPC) was determined to require screening to a maximum of 4,149 patients to enroll 259 patients for the targeted effect size. A nonenriched trial was determined to require enrolling 689 patients to be equivalently powered. We identified a pragmatic alternative, which is to enrich patients with mCRPC with a risk score of 1 or more (the 67th percentile) and an enrichment fraction of 0.25. This would require screening 658 patients to enroll 584 patients, and it maximizes the ability to detect a difference in treatment effect by risk score.

CONCLUSION

A plasma multi-CNA risk score classifier can feasibly be leveraged to design an enrichment trial in mCRPC. Enriching 25% of patients screened with a risk score >1 was observed to be optimal for obtaining an adequately powered, biomarker-based mCRPC-enriched clinical trial.

Prediction of Lesion-Based Treatment Response after Two Cycles of Lu-177 Prostate Specific Membrane Antigen Treatment in Metastatic Castration-Resistant Prostate Cancer Using Machine Learning

INTRODUCTION

Lutetium-177 (Lu-177) prostate-specific membrane antigen (PSMA) therapy is a radionuclide treatment that prolongs overall survival in metastatic castration-resistant prostate cancer (MCRPC). We aimed to predict lesion-based treatment response after Lu-177 PSMA treatment using machine learning with texture analysis data obtained from pretreatment Gallium-68 (Ga-68) PSMA positron emission tomography/computed tomography (PET/CT).

METHODS

Eighty-three progressed, and 91 nonprogressed malignant foci on pretreatment Ga-68 PSMA PET/CT of 9 patients were used for analysis. Malignant foci with at least a 30% increase in Ga-68 PSMA uptake after two cycles of treatment were considered progressed lesions. All other changes in Ga-68 PSMA uptake of the lesions were considered nonprogressed lesions. The classifiers tried to predict progressed lesions.

RESULTS

Logistic regression, Naive Bayes, and k-nearest neighbors' area under the ROC curve (AUC) values in detecting progressed lesions in the training group were 0.956, 0.942, and 0.950, respectively, and their accuracy was 87%, 85%, and 89%, respectively. The AUC values of the classifiers in the testing group were 0.937, 0.954, and 0.867, respectively, and their accuracy was 85%, 88%, and 79%, respectively.

CONCLUSION

Using machine learning with texture analysis data obtained from pretreatment Ga-68 PSMA PET/CT in MCRPC predicted lesion-based treatment response after two cycles of Lu-177 PSMA treatment.

The Influence of the Preoperative Albumin to Alkaline Phosphatase Ratio on Overall Survival in Post-Radical Surgery for Colorectal Cancer and the Construction of a Nomogram Prediction Model

PURPOSE

The albumin to alkaline phosphatase ratio (AAPR) is a newly developed blood biomarker that has been reported to have prognostic value in several types of cancers. The aim of this study was to investigate the predictive value of AAPR in overall survival after radical colon cancer surgery in patients with stage I-III colorectal cancer (CRC).

METHODS

The clinical data of 221 eligible patients with stage I ∼ III CRC were retrospectively analyzed. A series of survival analyses were performed to assess the prognostic value of AAPR. Univariate and multifactorial Cox analyses were performed to identify independent risk factors. Columnar graph prediction models were further constructed based on independent risk factors such as AAPR, and their predictive properties were validated.

RESULTS

The optimal cutoff value of preoperative AAPR for postoperative overall survival (OS) in patients undergoing laparoscopic radical CRC was .495 as shown by univariate and multifactorial Cox regression analysis. The factors of age ≤65 years, Tumor-Node-Metastasis (TNM) stage I-II, tumor grading (high/medium differentiation), CEA ≤5, and AAPR ≥.495 were associated with better OS (P < .05).

CONCLUSIONS

Preoperative AAPR level was a good predictor of postoperative survival in patients undergoing laparoscopic radical CRC surgery, and AAPR <.495 was an independent risk factor for decreased postoperative OS.

Prevalence and Prognostic Implications of PSA Flares during Radium-223 Treatment among Men with Metastatic Castration Resistant Prostate Cancer

Radium-223 (Ra233) prolongs the survival of men with symptomatic bone-predominant metastatic castration-resistant prostate cancer (mCRPC). However, prostate-specific antigen (PSA) response patterns are not closely associated with Ra223 therapy outcomes. Herein, we sought to analyze the impact of Ra223-induced PSA flares on patient outcome. Using a retrospective cohort study of Ra223 treatment in four Ontario/Canada cancer centres, we identified 134 patients grouped into sub-cohorts according to distinct PSA response patterns: (i) initial PSA flare followed by eventual PSA decline; (ii) PSA response (≥30% PSA decrease within 12 weeks of treatment); and (iii) PSA non-response. We analyzed patient characteristics and outcome measures, including overall survival (OS), using the Kaplan-Meier method and log-rank testing. PSA flares were observed in 27 (20.2%), PSA responses in 11 (8.2%), and PSA non-responses in 96 (71.6%) patients. Amongst PSA flare patients, 12 presented with post-flare PSA decreases below baseline and 15 with PSA decreases below the flare peak but above baseline. Although only six flare patients achieved ≥30% PSA decreases below baseline, the median OS of all flare patients (16.8 months, 95% CI 14.9-18.7) was comparable to that of PSA responders and non-responders (p = 0.349). In summary, around 20% of mCRPC patients experience Ra223-induced PSA flares, whose outcome is similar to that of men with or without PSA responses. Further studies are needed regarding suitable biochemical surrogate markers of response to Ra223.

Procoxacin bidirectionally inhibits osteoblastic and osteoclastic activity in bone and suppresses bone metastasis of prostate cancer

BACKGROUND

Bone is the most common site of metastasis of prostate cancer (PCa). PCa invasion leads to a disruption of osteogenic-osteolytic balance and causes abnormal bone formation. The interaction between PCa and bone stromal cells, especially osteoblasts (OB), is considered essential for the disease progression. However, drugs that effectively block the cancer-bone interaction and regulate the osteogenic-osteolytic balance remain undiscovered.

METHODS

A reporter gene system was constructed to screen compounds that could inhibit PCa-induced OB activation from 631 compounds. Then, the pharmacological effects of a candidate drug, Procoxacin (Pro), on OBs, osteoclasts (OCs) and cancer-bone interaction were studied in cellular models. Intratibial inoculation, micro-CT and histological analysis were used to explore the effect of Pro on osteogenic and osteolytic metastatic lesions. Bioinformatic analysis and experiments including qPCR, western blotting and ELISA assay were used to identify the effector molecules of Pro in the cancer-bone microenvironment. Virtual screening, molecular docking, surface plasmon resonance assay and RNA knockdown were utilized to identify the drug target of Pro. Experiments including co-IP, western blotting and immunofluorescence were performed to reveal the role of Pro binding to its target. Intracardiac inoculation metastasis model and survival analysis were used to investigate the therapeutic effect of Pro on metastatic cancer.

RESULTS

Luciferase reporter gene consisted of Runx2 binding sequence, OSE2, and Alp promotor could sensitively reflect the intensity of PCa-OB interaction. Pro best matched the screening criteria among 631 compounds in drug screening. Further study demonstrated that Pro effectively inhibited the PCa-induced osteoblastic changes without killing OBs or PCa cells and directly killed OCs or suppressed osteoclastic functions at very low concentrations. Mechanism study revealed that Pro broke the feedback loop of TGF-β/C-Raf/MAPK pathway by sandwiching into 14-3-3ζ/C-Raf complex and prevented its disassociation. Pro treatment alleviated both osteogenic and osteolytic lesions in PCa-involved bones and reduced the number of metastases of PCa in vivo.

CONCLUSIONS

In summary, our study provides a drug screening strategy based on the cancer-host microenvironment and demonstrates that Pro effectively inhibits both osteoblastic and osteoclastic lesions in PCa-involved bones, which makes it a promising therapeutic agent for PCa bone metastasis.

The Crucial Role of AR-V7 in Enzalutamide-Resistance of Castration-Resistant Prostate Cancer

Simple Summary

Androgen receptor splice variant 7 (AR-V7) has always been considered a key driver for triggering enzalutamide resistance of castration-resistant prostate cancer (CRPC). In recent years, both the homeostasis of AR-V7 protein and AR-V7’s relationship with LncRNAs have gained great attention with in-depth studies. Starting from protein stability and LncRNA, the paper discusses and summarizes the mechanisms and drugs that affect the CRPC patients’ sensitivity to enzalutamide by regulating the protein or transcriptional stability of AR-V7, hoping to provide therapeutic ideas for subsequent research to break through the CRPC therapeutic bottleneck.

Abstract

Prostate cancer (PCa) has the second highest incidence of malignancies occurring in men worldwide. The first-line therapy of PCa is androgen deprivation therapy (ADT). Nonetheless, most patients progress to castration-resistant prostate cancer (CRPC) after being treated by ADT. As a second-generation androgen receptor (AR) antagonist, enzalutamide (ENZ) is the current mainstay of new endocrine therapies for CRPC in clinical use. However, almost all patients develop resistance during AR antagonist therapy due to various mechanisms. At present, ENZ resistance (ENZR) has become challenging in the clinical treatment of CRPC. AR splice variant 7 (AR-V7) refers to a ligand-independent and constitutively active variant of the AR and is considered a key driver of ENZR in CRPC. In this review, we summarize the mechanisms and biological behaviors of AR-V7 in ENZR of CRPC to contribute novel insights for CRPC therapy.

Dynamic changes in gene alterations during chemotherapy in metastatic castrate resistant prostate cancer

Docetaxel chemotherapy is a standard treatment option for metastatic castrate resistant prostate cancer (mCRPC) patients. To date, the genomic perturbations underlying the emergence of resistance in mCRPC patients during chemotherapy treatment have not been fully characterized. Previous studies have established that AR, TP53, RB1 and PTEN gene alterations are frequent at this stage of progression and that TP53, RB1 and PTEN, but not AR alterations are associated with poor outcome. However, the clonal dynamics of these key driver cancer genes during chemotherapy in mCRPC patients have not been described. Toward this goal, we performed a retrospective analysis of serially profiled cell-free DNA (cfDNA) alterations in blood samples collected from mCRPC patients before and after starting chemotherapy who were followed for response and clinical outcomes. While AR alterations and measures of mutational load were significantly reduced in patients with stable or decreased PSA levels after 3 cycles of chemotherapy, reductions in RB1, TP53 and PTEN alterations were relatively modest, which may represent the persistence of a clonal signature associated with the emergence of treatment-induced lineage plasticity (TILP) underlying resistance. The ability to monitor these driver gene clonal dynamics during chemotherapy may have utility in the clinical setting.

Molecular mechanisms of docetaxel resistance in prostate cancer

Docetaxel (DTX) chemotherapy offers excellent initial response and confers significant survival benefit in patients with castration-resistant prostate cancer (CRPC). However, the clinical utility of DTX is compromised when primary and acquired resistance are encountered. Therefore, a more thorough understanding of DTX resistance mechanisms may potentially improve survival in patients with CRPC. This review focuses on DTX and discusses its mechanisms of resistance. We outline the involvement of tubulin alterations, androgen receptor (AR) signaling/AR variants, ERG rearrangements, drug efflux/influx, cancer stem cells, centrosome clustering, and phosphoinositide 3-kinase/AKT signaling in mediating DTX resistance. Furthermore, potential biomarkers for DTX treatment and therapeutic strategies to circumvent DTX resistance are reviewed.

MAGE-C2/CT10 promotes growth and metastasis through upregulating c-Myc expression in prostate cancer

Prostate cancer (PC) is the most common reproductive cancer in men and the third leading cause of cancer death among men worldwide. Recently targeted therapy showed a significant therapeutic effect on PC, whereas finding more PC therapeutic target is still urgently needed. Melanoma-associated antigen-encoding C2 (MAGE-C2/CT10), which have significant homology with the MAGE-C1/CT-7 gene, was known to be involved in the development of a variety of tumors. However, the role and mechanism of MAGE-C2/CT10 in prostate cancer remains unclear. Herein, we found the high levels of MAGE-C2/CT10 in highly metastatic prostate cancer. Our findings confirmed that the depletion of MAGE-C2/CT10 suppressed the growth of PC cells, and restrained PC cell migration and invasion in vitro. We noticed MAGE-C2/CT10 could stimulate c-Myc expression via FBP1, and further contributed to PC cell proliferation and motility. Performing in vivo assays, we demonstrated MAGE-C2/CT10 promoted tumor growth and metastasis of PC cells in mice. Collectively, we found the abnormal expression of MAGE-C2/CT10 in PC, and revealed the regulatory mechanism underlying MAGE-C2/CT10 promoting PC progression and metastasis.