Multimodal Biomarkers That Predict the Presence of Gleason Pattern 4: Potential Impact for Active Surveillance

PURPOSE

Latent grade group ≥2 prostate cancer can impact the performance of active surveillance protocols. To date, molecular biomarkers for active surveillance have relied solely on RNA or protein. We trained and independently validated multimodal (mRNA abundance, DNA methylation, and/or DNA copy number) biomarkers that more accurately separate grade group 1 from grade group ≥2 cancers.

MATERIALS AND METHODS

Low- and intermediate-risk prostate cancer patients were assigned to training (n=333) and validation (n=202) cohorts. We profiled the abundance of 342 mRNAs, 100 DNA copy number alteration loci, and 14 hypermethylation sites at 2 locations per tumor. Using the training cohort with cross-validation, we evaluated methods for training classifiers of pathological grade group ≥2 in centrally reviewed radical prostatectomies. We trained 2 distinct classifiers, PRONTO-e and PRONTO-m, and validated them in an independent radical prostatectomy cohort.

RESULTS

PRONTO-e comprises 353 mRNA and copy number alteration features. PRONTO-m includes 94 clinical, mRNAs, copy number alterations, and methylation features at 14 and 12 loci, respectively. In independent validation, PRONTO-e and PRONTO-m predicted grade group ≥2 with respective true-positive rates of 0.81 and 0.76, and false-positive rates of 0.43 and 0.26. Both classifiers were resistant to sampling error and identified more upgrading cases than a well-validated presurgical risk calculator, CAPRA (Cancer of the Prostate Risk Assessment; P < .001).

CONCLUSIONS

Two grade group classifiers with superior accuracy were developed by incorporating RNA and DNA features and validated in an independent cohort. Upon further validation in biopsy samples, classifiers with these performance characteristics could refine selection of men for active surveillance, extending their treatment-free survival and intervals between surveillance.

Total Quality Management in higher education: a literature review on barriers, customers and accreditation

Purpose

The purpose of this paper is to analyze the evolution of Total Quality Management (TQM) in terms of barriers, customers and accreditation in higher education (HE) over the last three decades (1991–2020) using literature review to establish the current state.

Design/methodology/approach

A total of 137 articles across 55 journals were consolidated for this review specifically focused on TQM (barriers, customers and accreditation) in HE. The investigations were carried out to identify the chronological growth of articles, research streams and methodologies. The articles were classified based on four research approaches and three research streams which have been reviewed in detail.

Findings

Considering the rapid growth in the HE sector and the concerns over reduction in quality of education especially in developing countries, the importance of TQM in HE is immense. The findings include identification of the barriers to successful TQM implementation, the need for alignment of TQM objectives of higher educational institutions (HEIs) and identified target customer(s) with the selected model/framework and the impact of accreditation/certification in the attainment of TQM.

Originality/value

This study which tries to bring a perspective to the main trends in TQM application to HE with respect to barriers, customers and accreditation over the last three decades is expected to add to the body of knowledge in this area and help future researchers to focus on the relevant areas identified in this paper.

The role of lifestyle characteristics on prostate cancer progression in two active surveillance cohorts

BACKGROUND

Although much research has examined the relationship between lifestyle and prostate cancer (PCa) risk, few studies focus on the relationship between lifestyle and PCa progression. The present study examines this relationship among men initially diagnosed with low- to intermediate-risk PCa and managed with active surveillance (AS).

METHODS

Men enrolled in two separate AS programs were recruited for this study. Data regarding clinical, demographic and lifestyle characteristics were collected. Results were then compared between men whose disease remained low- to intermediate-risk and men whose disease progressed.

RESULTS

Demographic, clinical and physical characteristics were similar between comparative groups and cohorts, with the exception that age at the time of diagnosis and questionnaire was increased among men whose disease progressed. Lifestyle scores among men who remained low- to intermediate-risk were higher than those whose risk progressed; however, scores were only significant in one cohort on univariable analysis. On multivariable analysis, the only predictor of progression was age at diagnosis. Physical activity was consistently higher in both low risk groups, although this difference was insignificant. Consistent differences in other lifestyle variables were not observed.

CONCLUSIONS

Age remains an important predictor of PCa progression. Improving lifestyle characteristics among men initially managed with AS might help to reduce the risk of progression. Given the limitations of this study, more rigorous investigation is required to confirm whether lifestyle characteristics influence the progression of low- to intermediate-risk PCa.

Metformin and prostate cancer stem cells: a novel therapeutic target

Prostate cancer is the second most frequently diagnosed cancer in the world. Localized disease can be effectively treated with radiation therapy or radical prostatectomy. However, advanced prostate cancer is more difficult to treat and if metastatic, is incurable. There is a need for more effective therapy for advanced prostate cancer. One potential target is the cancer stem cell (CSC). CSCs have been described in several solid tumors, including prostate cancer, and contribute to therapeutic resistance and tumor recurrence. Metformin, a common oral biguanide used to treat type 2 diabetes, has been demonstrated to have anti-neoplastic effects. Specifically, metformin targets CSCs in breast cancer, pancreatic cancer, glioblastoma and colon cancer. Metformin acts directly on the mitochondria to inhibit oxidative phosphorylation and reduce mitochondrial ATP production. This forces tumor cells to compensate by increasing the rate of glycolysis. CSCs rely heavily on mitochondrial oxidative phosphorylation for energy production. The glycolytic switch results in an energy crisis in these cells. Metformin could be used to exploit this metabolic weakness in CSCs. This would increase CSC sensitivity to conventional cancer therapies, circumventing treatment resistance and enhancing treatment efficacy. This review will explore the characteristics of prostate CSCs, their role in tumor propagation and therapeutic resistance and the role of metformin as a potential prostate CSC sensitizer to current anticancer therapies.

Utilizing metformin to enhance the efficacy of androgen-deprivation therapy in the treatment of prostate cancer

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Background: Prostate cancer (PCa) incidence varies by geographic location, with developed countries exhibiting higher levels of disease. Some attribute this to the “Westernized lifestyle” of high energy diets and limited physical activity with consequent obesity. Obesity and related diseases like diabetes, cause hyperinsulinemia, which upregulates pro-survival insulin/insulin-like growth factor signalling. Previous work shows diet-induced hyperinsulinemia enhances PCa tumor growth in vivo. Metformin, a diabetic treatment, reduces hyperinsulinemia, and also exhibits anti-neoplastic properties. We assessed the potential benefit of combining a standard PCa treatment (bicalutamide) with metformin in vitro and in vivo.

Methods: The effect of bicalutamide and/or metformin on colony formation rates was assessed in LNCaP, PC3, DU145 and PC3AR2 PCa cell lines using clonogenic assay. Western blot and cell cycle analyses were used to elucidate mechanisms of interaction between the drugs. The combination treatment regimen was assessed in vivo using a murine xenograft model.

Results: Micromolar bicalutamide or millimolar metformin caused significant dose-dependent reduction in colony formation rates (p<0.001). Combination treatment further significantly reduced colony formation rates (p<0.005). Differing mechanisms of interaction occurred in AR positive and negative cell lines. Following combination treatment LNCaP cells exhibited altered cell proliferation (decreased PCNA) and perturbed cell cycle kinetics (G1/S arrest). PC3 cells showed evidence of enhanced apoptosis (increased BAX, decreased caspase 3, phospho-Akt). Preliminary in vivo results show significantly diminished tumor growth following combination treatment (p<0.0001).

Conclusions: Combining bicalutamide and metformin significantly reduces PCa cell colony formation rates further than either monotherapy. In AR positive cells this effect is mediated by reducing cell proliferation rates, whereas in AR negative cells combination treatment promotes apoptosis. This combination drug regimen may potentially improve prostate-cancer specific survival via the direct anti-neoplastic properties outlined.

[Table: see text]

Utilizing metformin as a radiosensitizing agent in the treatment of prostate cancer

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Background: External beam radiation therapy (EBRT) is a well recognized curative prostate cancer (PCa) treatment modality utilizing ionizing radiation (IR). In addition to mediating DNA damage, IR upregulates several intracellular pro-survival pathways including the insulin- like growth factor (IGR) signaling network. This may contribute to the intrinsic radioresistance exhibited by certain tumors. Diabetic patients with PCa experience poorer outcomes following EBRT than their non-diabetic counterparts. Some attribute this to diabetes-induced chronic hyperinsulinemia with consequent upregulation of pro-survival insulin/IGF signalling. Previous work by our group showed diet-induced hyperinsulinemia to enhance PCa tumor growth in vivo. Metformin, a diabetic treatment, alleviates hyperinsulinemia, and also exhibits anti-neoplastic properties. We postulate that pre-treatment with metformin to correct hyperinsulinemia may protect cells from radiation-mediated pro-survival insulin/IGF signaling. Thus we assessed the radiosensitizing potential of metformin using in vitro and in vivo PCa models.

Methods: The effect of IR and/or metformin on colony formation rates was assessed in LNCaP, PC3, DU145 and PC3AR2 PCa cell lines using clonogenic assay. The combination treatment regimen was assessed in vivo using a murine xenograft model. Western blot and cell cycle analyses are ongoing to try and elucidate any mechanisms of interaction between metformin and IR.

Results: Monotherapy with IR (1-8Gy) or metformin (0.01-10.0mM) caused significant dose-dependent reduction in colony formation rates (p<0.001). Combination treatment further significantly reduced colony formation rates (p<0.03). Preliminary results from our in vivo study show diminished tumor growth in response to combination treatment (p<0.0001), and are currently subject to ongoing statistical analyses.

Conclusions: Our in vitro findings confirm combining metformin with IR significantly reduces PCa cell colony formation rates further than either monotherapy. Recapitulation of these results in vivo would provide justification for translating this work into a phase II clinical trial of metformin as a radiosensitizing agent.

No significant financial relationships to disclose.

Capsaicin, a novel radiosensitizer, acts via a TRPV6 mediated phenomenon

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Background: Radiosensitizing agents sensitize cells to the lethal effects of ionizing radiation (IR). This permits use of lower doses of radiation to achieve equivalent cancer control thereby minimizing adverse effects to normal tissues. Given their lack of toxicity compounds occurring naturally in the diet make ideal potential radiosensitizing agents. Capsaicin, a compound found in the Capsicum sp. of plants, is a widely consumed food additive in areas with low PCa incidence. Traditionally capsaicin is used to treat chronic pain syndromes; however, recently evidence using in vitro PCa models describes its anti-carcinogenic potential. The transient receptor potential vanilloid-receptor (TRPV)-1 and TRPV6 cation selective channels are thought to be partly responsible for mediating these effects. TRPV-1 and TRPV-6 expression is up-regulated in PCa tissue correlating directly with increasing tumor grade. This suggests TRPV1 and/or TRPV6 may be potential therapeutic targets for capsaicin mediated interventions in PCa patients. As IR and capsaicin both promote apoptosis and inhibit cell cycle progression in vitro we hypothesize an at least additive effect of combining these two therapies.

Methods: Using clonogenic assays we assessed the effect of ionizing radiation (1-8 Gy) and/or capsaicin (1-10μ M) on colony formation rates in 4 human PCa cell lines (LNCaP, PC3, PC3AR2, DU145). Proliferative, apoptotic, TRPV-6 protein markers were assessed using Western blot analyses.

Results: Exposure of cells to capsaicin (1-10μ M) or IR (1-8Gy) caused significant dose-dependent inhibition of colony formation (p<0.001). Combining capsaicin with IR resulted in further significant inhibition of colony formation rates (P<0.001). Western blot analyses showed LNCaP cells treated with capsaicin and/or IR to have increased expression of pro- apoptotic proteins BAX and Bad, tumor-suppressor proteins p21 and p27 and reduced androgen-receptor. Additionally, capsaicin monotherapy caused a dramaticalteration in TRPV1 and TRPV6 expression.

Conclusions: These studies confirm the radiosensitizing capacity of capsaicin in PCa cells in vitro. Ongoing studies are further delineating the mechanism of interaction of these treatment modalities.

No significant financial relationships to disclose.

Value addition to finger millet (Eleusine coracana) by germination and fermentation with Monascus purpureus

The present investigation has been carried out to highlight the importance of germination and fermentation of finger millet with Monascus purpureus. Finger millet was subjected to (i) germination, (ii) to fermentation with M. purpureus, and (iii) germination followed by fermentation with M. purpureus. The results of this experiment suggest that the germinated (72 h) finger millet fermented (10 days) with M. purpureus showed reduction in phytic acid and tannin contents by 88.8% and 90.1%, respectively, with an increase of 61.5% HCl-extractable minerals, reducing sugars and soluble proteins thereby supporting the production of antihypercholesterolemic metabolite, statin.

A genome-wide association screen identifies regions on chromosomes 1q25 and 7p21 as risk loci for sporadic prostate cancer

We conducted a genome-wide association study of 3090 sporadic prostate cancer patients and controls using the Affymetrix 10 000 SNP GeneChip. Initial screening of 40 prostate cancer cases and 40 non-cancer controls revealed 237 SNPs to be associated with prostate cancer (P<0.05). Among these SNPs, 33 were selected for further association analysis of 2069 men who had undergone a cancer-screening prostate biopsy. Results identified five loci as being significantly associated with increased prostate cancer risk in this larger sample (rs 1930293, OR=1.7, P=0.03; rs 717809-2p12, OR=1.3, P=0.03; rs 494770-4q34, OR=1.3, P=0.01; rs 2348763-7p21, OR=1.5, P=0.01; rs 1552895-9p22, OR=1.5, P=0.002). To validate these association data, 61 additional HapMap tagSNPs spanning the latter five loci were genotyped in this subject cohort and an additional 1021 men (total subject number=3090). This analysis revealed tag SNP rs 4568789 (chromosome 1q25) and tag SNP rs 13225697 (chromosome 7p21) to be significantly associated with prostate cancer (P-values 0.009 and 0.008, respectively). Haplotype analysis revealed significant associations of prostate cancer with two allele risk haplotypes on both chromosome 1q25 (adjusted OR of 2.7 for prostate cancer, P=0.0003) and chromosome 7p21 (adjusted OR of 1.3, P=0.0004). As linkage data have identified a putative prostate cancer gene on chromosome 1q25 (HPC1), and microarray data have revealed the ETV1 oncogene to be overexpressed in prostate cancer tissue, it appears that chromosome 1q25 and 7p21 may be sites of gene variants conferring risk for sporadic and inherited forms of prostate cancer.

Novel antiproliferative flavonoids induce cell cycle arrest in human prostate cancer cell lines

Epidemiologic studies have demonstrated an inverse association between flavonoid intake and prostate cancer (PCa) risk. The East Asian diet is very high in flavonoids and, correspondingly, men in China and Japan have the lowest incidence of PCa worldwide. There are thousands of different naturally occurring and synthetic flavonoids. However, only a few have been studied in PCa. Our aim was to identify novel flavonoids with antiproliferative effect in PCa cell lines, as well as determine their effects on cell cycle. We have screened a representative subgroup of 26 flavonoids for antiproliferative effect on the human PCa (LNCaP and PC3), breast cancer (MCF-7), and normal prostate stromal cell lines (PrSC). Using a fluorescence-based cell proliferation assay (Cyquant), we have identified five flavonoids, including the novel compounds 2,2'-dihydroxychalcone and fisetin, with antiproliferative and cell cycle arresting properties in human PCa in vitro. Most of the flavonoids tested exerted antiproliferative effect at lower doses in the PCa cell lines compared to the non-PCa cells. Flow cytometry was used as a means to determine the effects on cell cycle. PC3 cells were arrested in G2/M phase by flavonoids. LNCaP cells demonstrated different cell cycle profiles. Further studies are warranted to determine the molecular mechanism of action of 2,2'-DHC and fisetin in PCa, and to establish their effectiveness in vivo.

Synergistic effect of vitamin E and selenium in human prostate cancer cell lines

Vitamin E and selenium are the two most popular dietary supplements used to prevent prostate cancer. The hypothesis that these antioxidants reduce prostate risk is being tested in the selenium and vitamin E chemoprevention trial (SELECT). We hypothesize that selenium potentiates vitamin E-induced inhibition of prostate cancer cell growth in vitro. Prostate cancer cell populations growing asynchronously were treated with a combination of vitamin E and selenium and processed for flow cytometric analysis. Prostate cancer cells treated with a combination of the antioxidants revealed that selenium potentiates vitamin E-induced inhibition of LNCaP cells in vitro. This was demonstrated by a reduction in the percentage of cells in the S phase. This crucial finding confirms our previous observations that antioxidant molecules act via distinct mechanistic pathways. These independent biological effects can be exploited in order to augment the anticancer properties of individual agents. These data also validate the two factorial design of the SELECT trial, permitting pairwise comparisons between agents in combination and alone.

Salivary mesenchyme cells that induce mammary epithelial hyperplasia up-regulate EGF receptors in primary cultures of mammary epithelium within collagen gels

Salivary mesenchyme is a potent stimulator of mammary epithelial hyperplasia and carcinogen-induced tumor formation in vivo. We have utilized a three-dimensional collagen gel culture system, which mimics the in vivo growth environment, to identify growth stimulatory molecules produced by salivary mesenchyme cells. In this report we describe the development and characteristics of salivary mesenchyme cell lines, and we present further evidence that these cells produce growth factor(s) which could account for the effect by interacting with epidermal growth factor (EGF) receptors on primary mouse mammary epithelial cells isolated from midpregnant mice. Using a receptor assay with isolated cell membranes, we characterized [125I]-EGF binding to mammary epithelial cells cultured within collagen gels. Scatchard analysis revealed one class of high affinity EGF receptors with a Kd ranging from 8.3 x 10(-11) M on day one to 5.1 x 10(-11) M on day 10 of the culture period. Addition of 10 ng/ml purified EGF to the culture medium progressively up-regulated the expression of EGF receptors during a 10-day culture period. Scatchard analysis showed that the increase in specific [125I]-EGF binding was due predominantly to an increase in EGF receptor number. We also demonstrated that conditioned medium collected from salivary mesenchyme cells competed effectively for EGF receptor sites on mammary epithelial cells, and chronic exposure to conditioned medium up-regulated EGF receptor expression. Thus, EGF-related growth factor(s) released by salivary mesenchyme cells may induce hyperplasia of adjacent mammary epithelium in vivo, both by directly activating EGF receptors, and by provoking long term up-regulation of EGF receptors.

A transforming growth factor related to epidermal growth factor is expressed by fetal mouse salivary mesenchyme cells in culture

Fetal mouse salivary mesenchyme cells secrete a protein with an apparent MW of 15 Kd that is immunologically related to epidermal growth factor (EGF). Conditioned medium collected from these cells in culture stimulates the growth of primary mouse mammary epithelial cells cultured within collagen gels, competes for binding to EGF receptor sites on these mammary epithelial cells and stimulates the anchorage-independent growth of normal rat kidney fibroblast cells within soft agarose. Prior immunoprecipitation of salivary mesenchyme cell conditioned medium with anti-EGF antibodies effectively removes or attenuates all of these effects confirming that an EGF-like factor is involved in these responses.