Identification of Bone Metastatic and Prognostic Alternative Splicing Signatures in Prostate Adenocarcinoma

As the most common nonepithelial malignancy, prostate adenocarcinoma (PRAD) is the fifth chief cause of cancer mortality in men. Distant metastasis often occurs in advanced PRAD and most patients are dying from it. However, the mechanism of PRAD progression and metastasis is still unclear. It's widely reported that more than 94% of genes are selectively splicing in humans and many isoforms are particularly related with cancer progression and metastasis. Spliceosome mutations occur in a mutually exclusive manner in breast cancer, and different components of spliceosomes are targets of somatic mutations in different types of breast cancer. Existing evidence strongly supports the key role of alternative splicing in breast cancer biology, and innovative tools are being developed to use splicing events for diagnostic and therapeutic purposes. In order to identify if the PRAD metastasis is associated with alternative splicing events (ASEs), the RNA sequencing data and ASEs data of 500 PRAD patients were retrieved from The Cancer Genome Atlas (TCGA) and TCGASpliceSeq databases. By Lasso regression, five genes were screened to construct the prediction model, with a good reliability by ROC curve. Additionally, results in both univariate and multivariate Cox regression analysis confirmed the well prognosis efficacy of the prediction model (both P < 0.001). Moreover, a potential splicing regulatory network was established and after multiple-database validation, we supposed that the signaling axis of HSPB1 up-regulating the PIP5K1C - 46,721 - AT (P < 0.001) might mediate the tumorigenesis, progression and metastasis of PRAD via the key members of Alzheimer's disease pathway (SRC, EGFR, MAPT, APP and PRKCA) (P < 0.001).

Genomic biomarkers to guide precision radiotherapy in prostate cancer

Our ability to prognosticate the clinical course of patients with cancer has historically been limited to clinical, histopathological, and radiographic features. It has long been clear however, that these data alone do not adequately capture the heterogeneity and breadth of disease trajectories experienced by patients. The advent of efficient genomic sequencing has led to a revolution in cancer care as we try to understand and personalize treatment specific to patient clinico-genomic phenotypes. Within prostate cancer, emerging evidence suggests that tumor genomics (e.g., DNA, RNA, and epigenetics) can be utilized to inform clinical decision making. In addition to providing discriminatory information about prognosis, it is likely tumor genomics also hold a key in predicting response to oncologic therapies which could be used to further tailor treatment recommendations. Herein we review select literature surrounding the use of tumor genomics within the management of prostate cancer, specifically leaning toward analytically validated and clinically tested genomic biomarkers utilized in radiotherapy and/or adjunctive therapies given with radiotherapy.

Implications of DNA damage repair alterations for the management of prostate cancer

PURPOSE OF REVIEW

In this review, we summarize the prevalence of alterations in DNA damage repair (DDR) genes in prostate cancer, their clinical significance, the therapeutic strategies developed to take advantage of the impaired tumour ability to repair DNA and the diagnostic approaches available to identify patients likely to benefit from DDR-targeting agents.

RECENT FINDINGS

DDR alterations are more frequent in metastatic than in localized prostate cancer and some of them associate with aggressive disease whereas the significance of others remain unclear. The most appropriate management approach for DDR-defective prostate cancer patients is unknown. Clinical trials have demonstrated the efficacy of different poly-ADP ribose polymerase inhibitors (PARPi) to treat metastatic castration-resistant prostate cancer patients with BRCA1/2 alterations, although there may be other DDR alterations that sensitize patients to these drugs. Multiple strategies to target DDR defects are being investigated, including PARPi in combination, platinum-based chemotherapy and immunotherapy, both in earlier and late disease stages. Optimization of molecular testing is paramount for the implementation of precision oncology in prostate cancer.

SUMMARY

Certain DDR defects present in prostate cancer have prognostic and therapeutic implications whereas the significance of other DDR alterations is yet to be elucidated.

Circulating androgen receptor gene amplification and resistance to 177Lu-PSMA-617 in metastatic castration-resistant prostate cancer: results of a Phase 2 trial

BACKGROUND

In a Phase 2 clinical trial, we aimed to determine the lutetium-177 [¹⁷⁷Lu]-PSMA-617 activity and the clinical utility of levels of plasma androgen receptor (AR) gene in patients with heavily pretreated metastatic castration-resistant prostate cancer (mCRPC).

METHODS

We determined AR copy number in pretreatment plasma samples. We used logistic regression to estimate the odds ratio (OR) and 95% confidence intervals (95% CIs) in order to evaluate the independent relevance of AR status and to evaluate patients with early progressive disease (PD) defined as treatment interruption occurring within 4 months after the start of ¹⁷⁷Lu-PSMA-617.

RESULTS

Twelve of the 15 (80%) with AR gene gain and 5 of the 25 (20%) patients with no gain of AR had early PD (p = 0.0002). The OR for patients without PSA response having AR gain was 3.69 (95% CI 0.83-16.36, p = 0.085). The OR for patients with early PD having AR gain was 16.00, (95% CI 3.23-79.27, p = 0.0007). Overall, median PFS and OS were 7.5 and 12.4 months, respectively. AR-gained had a significant shorter OS compared to AR-normal patients (7.4 vs 19.1 months, p = 0.020). No treatment interruptions due to adverse effects were reported.

DISCUSSION

Plasma AR status helped to indicate mCRPC with early resistance to ¹⁷⁷Lu-PSMA-617.

TRIAL REGISTRATION

NCT03454750.

Biomarkers in Prostate-Specific Membrane Antigen Theranostics

Theranostics of prostate cancer (PC) represents a growing area of development of imaging agents and targeted radionuclide therapeutics against a major target, prostate specific membrane antigen (PSMA). In view of the encouraging efficacy from the use of ¹⁷⁷Lu and other radionuclides in metastatic castration-resistant prostate cancer (mCRPC), it is becoming increasingly important to identify surrogate markers that can help predict which patients are more likely to respond and experience improved survival. This review discusses potential predictors of efficacy of PSMA-targeted radionuclide therapies (TRT) segregated in three major categories: imaging, clinical and molecular.

Genetic Contribution to Metastatic Prostate Cancer

Recent studies show that the prevalence of germline pathogenic and likely pathogenic variants (also known as mutations) in DNA repair genes in metastatic prostate cancer is higher than previously recognized and higher than in unaffected men. Specific gene dysfunction is important in prostate cancer initiation and/or evolution to metastases. This article reviews key literature on individual genes, recognizing BRCA2 as the gene most commonly altered in the metastatic setting. This article discusses the importance of representative and diverse inclusion, and efforts to advance management for at-risk carrier populations to maximize clinical benefit.

Meeting report from the Prostate Cancer Foundation PSMA theranostics state of the science meeting

INTRODUCTION

The Prostate Cancer Foundation (PCF) convened a PCF prostate-specific membrane antigen (PSMA) Theranostics State of the Science Meeting on 18 November 2019, at Weill Cornell Medicine, New York, NY.

METHODS

The meeting was attended by 22 basic, translational, and clinical researchers from around the globe, with expertise in PSMA biology, development and use of PSMA theranostics agents, and clinical trials. The goal of this meeting was to discuss the current state of knowledge, the most important biological and clinical questions, and critical next steps for the clinical development of PSMA positron emission tomography (PET) imaging agents and PSMA-targeted radionuclide agents for patients with prostate cancer.

RESULTS

Several major topic areas were discussed including the biology of PSMA, the role of PSMA-targeted PET imaging in prostate cancer, the physics and performance of different PSMA-targeted PET imaging agents, the current state of clinical development of PSMA-targeted radionuclide therapy (RNT) agents, the role of dosimetry in PSMA RNT treatment planning, barriers and challenges in PSMA RNT clinical development, optimization of patient selection for PSMA RNT trials, and promising combination treatment approaches with PSMA RNT.

DISCUSSION

This article summarizes the presentations from the meeting for the purpose of globally disseminating this knowledge to advance the use of PSMA-targeted theranostic agents for imaging and treatment of patients with prostate cancer.