Racial Difference in Prostate Cancer Cell Telomere Lengths in Men with Higher Grade Prostate Cancer: A Clue to the Racial Disparity in Prostate Cancer Outcomes

The Notable Role of Telomere Length Maintenance in Complex Diseases

Telomere length function serves as a critical biomarker for biological aging and overall health. Its maintenance is linked to cancer, neurodegenerative conditions, and reproductive health. This review mainly examines genetic variations and environmental influences on telomere dynamics, highlighting key regulatory genes and mechanisms. Advances in telomere measurement methodologies are also reviewed, underscoring the importance of precise telomere assessment for disease prevention and treatment. Telomerase activation offers potential for cellular lifespan extension and anti-aging effects, whereas its inhibition emerges as a promising therapeutic approach for cancer. Regulatory mechanisms of tumor suppressor genes on telomerase activity are analyzed, with a comprehensive overview of the current state and future potential of telomerase inhibitors. In addition, the association between telomeres and neurodegenerative diseases is discussed, detailing how telomere attrition heightens disease risk and outlining multiple pathways by which telomerase protects neurons from damage and apoptosis.

Longer prostate stromal cell telomere length is associated with increased risk of death from other cancers

Background

Telomeres are located at chromosomal termini and function to maintain genomic integrity. Telomere dysfunction is a well-recognized contributor to aging and age-related diseases, such as prostate cancer. Since telomere length is highly heritable, we postulate that stromal cell telomere length in the tissue of a particular solid organ may generally reflect constitutive stromal cell telomere length in other solid organs throughout the body. Even with telomere loss occurring with each round of cell replication, in general, telomere length in prostate stromal cells in mid-life would still be correlated with the telomere length in stromal cells in other organs. Thus, we hypothesize that prostate stromal cell telomere length and/or telomere length variability is a potential indicator of the likelihood of developing future solid cancers, beyond prostate cancer, and especially lethal cancer.

Methods

To explore this hypothesis, we conducted a cohort study analysis of 1,175 men who were surgically treated for prostate cancer and were followed for death, including from causes other than their prostate cancer.

Results

In this cohort study with a median follow-up of 19 years, we observed that longer prostate stromal cell telomere length measured in tissue microarray spots containing prostate cancer was associated with an increased risk of death from other solid cancers. Variability in telomere length among these prostate stromal cells was possibly positively associated with risk of death from other solid cancers.

Conclusion

Studying the link between stromal cell telomere length and cancer mortality may be important for guiding the development of cancer interception and prevention strategies.

Genetic and biological drivers of prostate cancer disparities in Black men

Black men with prostate cancer have historically had worse outcomes than white men with prostate cancer. The causes of this disparity in outcomes are multi-factorial, but a potential basis is that prostate cancers in Black men are biologically distinct from prostate cancers in white men. Evidence suggests that genetic and ancestral factors, molecular pathways involving androgen and non-androgen receptor signalling, inflammation, epigenetics, the tumour microenvironment and tumour metabolism are contributing factors to the racial disparities observed. Key genetic and molecular pathways linked to prostate cancer risk and aggressiveness have potential clinical relevance. Describing biological drivers of prostate cancer disparities could inform efforts to improve outcomes for Black men with prostate cancer.

Chromogenic detection of telomere lengths in situ aids the identification of precancerous lesions in the prostate

BACKGROUND

Telomeres are terminal chromosomal elements that are essential for the maintenance of genomic integrity. The measurement of telomere content provides useful diagnostic and prognostic information, and fluorescent methods have been developed for this purpose. However, fluorescent-based tissue assays are cumbersome for investigators to undertake, both in research and clinical settings.

METHODS

A robust chromogenic in situ hybridization (CISH) approach was developed to visualize and quantify telomere content at single cell resolution in human prostate tissues, both frozen and formalin-fixed, paraffin-embedded (FFPE).

RESULTS

This new assay (telomere chromogenic in situ hybridization ["Telo-CISH"]) produces permanently stained slides that are viewable with a standard light microscope, thus avoiding the need for specialized equipment and storage. The assay is compatible with standard immunohistochemistry, thereby allowing simultaneous assessment of histomorphology, identification of specific cell types, and assessment of telomere status. In addition, Telo-CISH eliminates the problem of autofluorescent interference that frequently occurs with fluorescent-based methods. Using this new assay, we demonstrate successful application of Telo-CISH to help identify precancerous lesions in the prostate by the presence of markedly short telomeres specifically in the luminal epithelial cells.

CONCLUSIONS

In summary, with fewer restrictions on the types of tissues that can be tested, and increased histologic information provided, the advantages presented by this novel chromogenic assay should extend the applicability of tissue-based telomere length assessment in research and clinical settings.

Role of telomere length in human carcinogenesis (Review)

Cancer is considered the most important clinical, social and economic issue regarding cause‑specific disability‑adjusted life years among all human pathologies. Exogenous, endogenous and individual factors, including genetic predisposition, participate in cancer triggering. Telomeres are specific DNA structures positioned at the end of chromosomes and consist of repetitive nucleotide sequences, which, together with shelterin proteins, facilitate the maintenance of chromosome stability, while protecting them from genomic erosion. Even though the connection between telomere status and carcinogenesis has been identified, the absence of a universal or even a cancer‑specific trend renders consent even more complex. It is indicative that both short and long telomere lengths have been associated with a high risk of cancer incidence. When evaluating risk associations between cancer and telomere length, a disparity appears to emerge. Even though shorter telomeres have been adopted as a marker of poorer health status and an older biological age, longer telomeres due to increased cell growth potential are associated with the acquirement of cancer‑initiating somatic mutations. Therefore, the present review aimed to comprehensively present the multifaceted pattern of telomere length and cancer incidence association.

The prostate tissue‐based telomere biomarker as a prognostic tool for metastasis and death from prostate cancer after prostatectomy

Current biomarkers are inadequate prognostic predictors in localized prostate cancer making treatment decision‐making challenging. Previously, we observed that the combination of more variable telomere length among prostate cancer cells and shorter telomere length in prostate cancer‐associated stromal cells – the telomere biomarker – is strongly associated with progression to metastasis and prostate cancer death after prostatectomy independent of currently used pathologic indicators. Here, we optimized our method allowing for semi‐automated telomere length determination in single cells in fixed tissue, and tested the telomere biomarker in five cohort studies of men surgically treated for clinically localized disease (N = 2,255). We estimated the relative risk (RR) of progression to metastasis (N = 311) and prostate cancer death (N = 85) using models appropriate to each study's design adjusting for age, prostatectomy stage, and tumor grade, which then we meta‐analyzed using inverse variance weights. Compared with men who had less variable telomere length among prostate cancer cells and longer telomere length in prostate cancer‐associated stromal cells, men with the combination of more variable and shorter telomere length had 3.76 times the risk of prostate cancer death (95% confidence interval [CI] 1.37–10.3, p = 0.01) and had 2.23 times the risk of progression to metastasis (95% CI 0.99–5.02, p = 0.05). The telomere biomarker was associated with prostate cancer death in men with intermediate risk disease (grade groups 2/3: RR = 9.18, 95% CI 1.14–74.0, p = 0.037) and with PTEN protein intact tumors (RR = 6.74, 95% CI 1.46–37.6, p = 0.015). In summary, the telomere biomarker is robust and associated with poor outcome independent of current pathologic indicators in surgically treated men.

Race Differences in Telomere Length in Benign Prostate Biopsies and Subsequent Risk of Prostate Cancer

BACKGROUND

Telomere shortening is linked to aging and may be associated with increased risk for cancer. Most cancer studies have used telomere length in leukocytes rather than in the target tissue of cancer origin.

METHODS

A case-control study of 524 case-control pairs with a benign prostate biopsy nested within a historical cohort of 10,478 men was conducted to determine whether premalignant prostate telomere length (assessed using a modified qRT-PCR) is associated with prostate cancer risk.

RESULTS

Telomere lengths in benign prostate biopsies of cases versus controls were similar (1.46 ± 0.38 vs. 1.45 ± 0.42; P = 0.49). African American (AA) men had significantly shorter telomeres compared with White men (1.51 ± 0.38 vs. 1.63 ± 0.39; P < 0.0001). In race-stratified analyses, increasing telomere length was more strongly associated with prostate cancer risk in White men, wherein those with telomere length in the highest quartile had 1.9-fold greater adjusted risk of prostate cancer compared with men with prostate telomere lengths in the lowest quartile [OR = 1.90; 95% confidence interval (CI) = 1.08-3.36]. Men in the highest telomere length quartile also had a greater risk of aggressive prostate cancer compared with men with telomere lengths in the lowest quartile (OR = 2.78; 95% CI = 1.25-6.19).

CONCLUSIONS

White men have longer telomeres in benign prostate tissue compared with AA men, and those with the longest telomeres may be at increased risk for prostate cancer, particularly the more aggressive form of the disease.

IMPACT

Race-specific telomere length measures may be an early biomarker of aggressive prostate cancer.

Population-Level Patterns of Prostate Cancer Occurrence: Disparities in Virginia

Prostate cancer is the most common cancer and the second leading cause of cancer-related deaths among men in the United States. In Virginia, which is a representative, ethnically diverse state of more than 8 million people that was established nearly 400 years ago, prostate cancer has the highest rate of new detection for any type of cancer. All men are at risk of developing prostate cancer regardless of demographics, but some men have an increased mortality risk due to cancer metastasis. Notably, one in five African American men will be diagnosed with prostate cancer in their lifetime and they have the highest prostate cancer mortality rate of any ethnic group in the United States, including Virginia. A person's genetic profile and family history are important biological determinants of prostate cancer risk, but modifiable environmental factors (e.g., pollution) appear to be correlated with patterns of disease prevalence and risk. In this review, we examine current perspectives on population-level spatial patterns of prostate cancer in Virginia. For context, recent, publicly available data from the Centers for Disease Control and Prevention are highlighted and presented in spatial format. In addition, we explore possible co-morbidities of prostate cancer that may have demographic underpinnings highlighted in recent health disparity studies.

Racial disparities in prostate cancer: A complex interplay between socioeconomic inequities and genomics

The largest US cancer health disparity exists in prostate cancer, with Black men having more than a two-fold increased risk of dying from prostate cancer compared to all other races. This disparity is a result of a complex network of factors including socioeconomic status (SES), environmental exposures, and genetics/biology. Inequity in the US healthcare system has emerged as a major driver of disparity in prostate cancer outcomes and has raised concerns that the actual incidence rates may be higher than current estimates. However, emerging studies argue that equalizing healthcare access will not fully eliminate racial health disparities and highlight the important role of biology. Significant differences have been observed in prostate cancer biology between various ancestral groups that may contribute to prostate cancer health disparities. These differences include enhanced androgen receptor signaling, increased genomic instability, metabolic dysregulation, and enhanced inflammatory and cytokine signaling. Immediate actions are needed to increase the establishment of adequate infrastructure and multi-center, interdisciplinary research to bridge the gap between social and biological determinants of prostate cancer health disparities.

Cardiovascular Toxicities of Androgen Deprivation Therapy

OPINION STATEMENT

Prostate cancer is the second leading cause of cancer death in men, and cardiovascular disease is the number one cause of death in patients with prostate cancer. Androgen deprivation therapy, the cornerstone of prostate cancer treatment, has been associated with adverse cardiovascular events. Emerging data supports decreased cardiovascular risk of gonadotropin releasing hormone (GnRH) antagonists compared to agonists. Ongoing clinical trials are assessing the relative safety of different modalities of androgen deprivation therapy. Racial disparities in cardiovascular outcomes in prostate cancer patients are starting to be explored. An intriguing inquiry connects androgen deprivation therapy with reduced risk of COVID-19 infection susceptibility and severity. Recognition of the cardiotoxicity of androgen deprivation therapy and aggressive risk factor modification are crucial for optimal patient care.

Obesity is Associated with Shorter Telomere Length in Prostate Stromal Cells in Men with Aggressive Prostate Cancer

In our prior studies, obesity was associated with shorter telomeres in prostate cancer-associated stromal (CAS) cells, and shorter CAS telomeres were associated with an increased risk of prostate cancer death. To determine whether the association between obesity and shorter CAS telomeres is replicable, we conducted a pooled analysis of 790 men who were surgically treated for prostate cancer, whose tissue samples were arrayed on five tissue microarray (TMA) sets. Telomere signal was measured using a quantitative telomere-specific FISH assay and normalized to 4',6-diamidino-2-phenylindole for 351 CAS cells (mean) per man; men were assigned their median value. Weight and height at surgery, collected via questionnaire or medical record, were used to calculate body mass index (BMI; kg/m²) and categorize men as normal (<25), overweight (25 ≤ BMI < 30), or obese (≥30). Analyses were stratified by grade and stage. Men were divided into tertiles of TMA- (overall) or TMA- and disease aggressiveness- (stratified) specific distributions; short CAS telomere status was defined by the bottom two tertiles. We used generalized linear mixed models to estimate the association between obesity and short CAS telomeres, adjusting for age, race, TMA set, pathologic stage, and grade. Obesity was not associated with short CAS telomeres overall, or among men with nonaggressive disease. Among men with aggressive disease (Gleason≥4+3 and stage>T2), obese men had a 3-fold increased odds of short CAS telomeres (OR: 3.06; 95% confidence interval: 1.07-8.75; P _trend = 0.045) when compared with normal weight men. Telomere shortening in prostate stromal cells may be one mechanism through which lifestyle influences lethal prostate carcinogenesis. PREVENTION RELEVANCE: This study investigates a potential mechanism underlying the association between obesity and prostate cancer death. Among men with aggressive prostate cancer, obesity was associated with shorter telomeres prostate cancer associated stromal cells, and shorter CAS telomeres have been associated with an increased risk of prostate cancer death.

Circulatory MIC-1 as a Determinant of Prostate Cancer Racial Disparity

Simple Summary

African American men are diagnosed with more aggressive prostate cancer and have worse outcomes than Caucasians. This study examined the role of MIC-1 as a risk factor and demonstrated a conceptual observation for the differential level of MIC-1 in circulation (serum and urine) and tumor tissues from prostate cancer patients of racial disparity. The circulatory MIC-1 levels in serum and urine are significantly higher in prostate cancer patients of African American ethnicity, with higher sensitivity and specificity than Caucasians. The validation of circulatory MIC-1 in a larger cohort of patients may help identify high-risk prostate cancer patients and develop race-oriented therapies to reduce the observed cancer outcome gaps between the races.

Abstract

In this study, we investigated the potential of MIC-1 (macrophage inhibitory cytokine-1) on the severity of prostate cancer between African American men and Caucasians. Differences between the races were examined using Mann–Whitney tests for continuous variables and Fisher’s exact tests for categorical variables. Pearson’s correlation coefficient was used to identify associations between continuous measures across all samples and within each race. Analysis of variance, including clinical parameters, was used to identify differences in serum and urine MIC-1 levels between races. We found significant differences between the two races for age (p = 0.01), Gleason scores (p = 0.01), and stage of disease (p = 0.03). African American men in the study had higher Gleason scores (mean = 6.9) than Caucasians (mean = 6.5), during earlier stages of the disease. In Caucasian men with prostate cancer, serum MIC-1 expression was positively associated with age (r = 0.7, p < 0.01). However, African American men had highly expressed MIC-1 and high Gleason scores (r = 0.16, p = 0.3). Interestingly, the urine MIC-1 level was significantly higher in African American men with prostate cancer than in Caucasian patients. It appeared to be more sensitive and specific for African Americans (AUC = 0.85 vs. 0.56). Thus, high circulatory MIC-1 in prostate cancer patients may indicate MIC-1 as a potential biomarker to improve the diagnostic ability of an aggressive stage of prostate cancer in African American men. However, a larger cohort of sample analysis is required to validate these observations.