Use of TP4303 to identify prostate cancer cells in voided urine samples.

INTRODUCTION: Prostate cancer is the second most common malignancy in men worldwide. Genomic VPAC receptors are expressed on malignant prostate cancer cells and can be targeted and imaged optically by a peptide labeled fluorophore. The objective of our study was to assess the feasibility of detecting cancer of the prostate using a voided urine sample. MATERIALS AND METHODS: Patients ≥ 40 years old, with lower urinary tract symptoms and serum PSA > 4 ng/mL formed the study group. The first 50 mL of voided urine sample was collected and processed. The cells that were shed in the voided urine were fixed and stained with a peptide TP4303 and incubated. The slide was then stained with DAPI which binds with the DNA in the nucleus. All patients underwent a standard 12-core TRUS-guided prostate biopsy. RESULTS: A total of 318 patients were included in the study, of these 158 were histologically confirmed cancers. Voided urine samples were positive for VPAC receptors in 154 (97.46%) of these. The remaining 160 patients had no cancer on the HPR examination and none of these patients were positive for VPAC receptors. CONCLUSIONS: This study validates our belief that patients with prostate cancer shed malignant cells in the urine that can be identified by targeting the VPAC receptors. If these results are further validated by multicentric studies, then this could form the basis for indications for a preliminary prostate biopsy in patients with elevated serum PSA but normal digital examination or in patients needing a repeat biopsy.

Diagnosis of Oral Cancers by Targeting VPAC Receptors: Preliminary Report.

INTRODUCTION: Oral cancer is a major health problem. The study of exfoliative cytology material helps in the differentiation of premalignant and malignant alterations of oral lesions. The objective of this study was to assess the feasibility of detecting oral cancer by targeting genomic VPAC (combined vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide) receptors expressed on malignant oral cancer cells. PATIENTS & METHODS: All patients with suspected oral cavity cancers/lesions formed the study group. The samples from the oral cavity lesion or suspicious area were collected with a cytology brush. The harvested material was examined for malignant cells by 1. the standard PAP stain and 2. targeting the VPAC receptors on the cell surface using a fluorescent microscope. Similarly, malignant cells were identified from cells shed in oral gargles. RESULTS: A total of 60 patients with oral lesions were included in the study. The histopathological diagnosis was squamous cell carcinoma in 30 of these. The VPAC receptor positivity both on the brush cytology staining as well oral gargle staining was more sensitive than the brush cytology PAP staining. The accuracy of the various techniques was as follows, brush cytology PAP staining at 86.67%, brush cytology VPAC staining at 91.67% and oral gargle VPAC staining at 95%. CONCLUSIONS: This preliminary study validates our belief that malignant cells in the saliva can be identified by targeting the VPAC receptors. The test is simple, easy, non-invasive and reliable in the detection of oral cancers.

Voided urine test to diagnose prostate cancer: Preliminary report.

OBJECTIVES: Prostate cancer (PCa) is a common malignancy affecting elderly male. At present, PCa is estimated using serum prostate-specific antigen (PSA). Prostate biopsy remains the gold standard to confirm the diagnosis of PCa. In this preliminary study, we have assessed the feasibility of detecting PCa using voided urine by targeting the genomic vasoactive intestinal peptide receptor (VPAC) expressed on malignant PCa cells. MATERIAL AND METHODS: Patients ≥40 years old, with no lower urinary tract symptoms (LUTS) and serum PSA levels of <1.6 ng/mL formed the control group and patients ≥40 years old, with LUTS and serum PSA >2.6 ng/ mL formed the study group. Patients were advised to give the first 50 mL of voided urine sample for the detection of malignant markers by targeting the VPAC. The results of histopathological studies were then compared to the results of urine biomarker. RESULTS: The study revealed absence of malignant markers in 75 patients (control group). In the study group, all the 33 patients with adenocarcinoma were positive for malignant markers in the biomarker study and absence of malignant markers in the 32 patients with benign histology. The results of the biomarker studies and histopathology were consistent with each other. CONCLUSION: This preliminary study validates our belief that patients with PCa do shed malignant cells in the urine which can be identified by targeting the VPAC. The investigation is easy and our data appear to be highly encouraging and further serve as a simple, reliable, and a non-invasive tool in the detection of PCa.

Detection of bladder cancer using voided urine sample and by targeting genomic VPAC receptors.

INTRODUCTION: Cells exfoliated into urine from the bladder can help to diagnose the cancer. The objective of this study was to validate the hypothesis that bladder cancer could be detected noninvasively by a simple and reliable assay targeting genomic VPAC (combined vasoactive intestinal peptide and pituitary adenylate cyclase-activating peptide family of cell surface receptors) receptors expressed on the malignant bladder cancer cells shed in the voided urine. METHODS: Patients ≥18 years of age with either imaging (ultrasonography/computed tomography [CT])-confirmed bladder tumors or those who have been previously treated for nonmuscle invasive bladder tumors and were visiting the department for check cystoscopy, formed the study group. Freshly voided urine sample was collected from these patients and sent for conventional cytology examination, 5-aminolevulinic acid (ALA) fluorescent urine cytology, and for positivity of VPAC receptors. RESULTS: A total of 103 patients were prospectively included in the study. Of these, 65 patients (Group I) presented with image-diagnosed (ultrasonography and/or CT) bladder cancer. The remaining 38 patients (Group II) were previously diagnosed cases of nonmuscle invasive bladder cancer and presented for follow-up and check cystoscopy. The sensitivity for VPAC receptor positivity was 89.23% compared to conventional cytology (63.07%) and 5-ALA fluorescent urine cytology (87.69%). The specificity of VPAC receptor positivity was 100% compared to conventional cytology (100%) and 5-ALA-induced fluorescent cytology (90.47%). CONCLUSIONS: Our preliminary study shows encouraging results with VPAC receptor positivity studies, which has a high sensitivity when compared to the conventional cytology.

Prostate cancer sheds the αvß3 integrin in vivo through exosomes.

The αvß3 integrin has been shown to promote aggressive phenotypes in many types of cancers, including prostate cancer. We show that GFP-labeled αvß3 derived from cancer cells circulates in the blood and is detected in distant lesions in NOD scid gamma (NSG) mice. We, therefore, hypothesized that αvß3 travels through exosomes and tested its levels in pools of vesicles, which we designate extracellular vesicles highly enriched in exosomes (ExVs), and in exosomes isolated from the plasma of prostate cancer patients. Here, we show that the αvß3 integrin is found in patient blood exosomes purified by sucrose or iodixanol density gradients. In addition, we provide evidence that the αvß3 integrin is transferred through ExVs isolated from prostate cancer patient plasma to ß3-negative recipient cells. We also demonstrate the intracellular localization of ß3-GFP transferred via cancer cell-derived ExVs. We show that the ExVs present in plasma from prostate cancer patients contain higher levels of αvß3 and CD9 as compared to plasma ExVs from age-matched subjects who are not affected by cancer. Furthermore, using PSMA antibody-bead mediated immunocapture, we show that the αvß3 integrin is expressed in a subset of exosomes characterized by PSMA, CD9, CD63, and an epithelial-specific marker, Trop-2. Finally, we present evidence that the levels of αvß3, CD63, and CD9 remain unaltered in ExVs isolated from the blood of prostate cancer patients treated with enzalutamide. Our results suggest that detecting exosomal αvß3 integrin in prostate cancer patients could be a clinically useful and non-invasive biomarker to follow prostate cancer progression. Moreover, the ability of αvß3 integrin to be transferred from ExVs to recipient cells provides a strong rationale for further investigating the role of αvß3 integrin in the pathogenesis of prostate cancer and as a potential therapeutic target.

Deletion of the mitochondrial chaperone TRAP-1 uncovers global reprogramming of metabolic networks.

Reprogramming of metabolic pathways contributes to human disease, especially cancer, but the regulators of this process are unknown. Here, we have generated a mouse knockout for the mitochondrial chaperone TRAP-1, a regulator of bioenergetics in tumors. TRAP-1(-/-) mice are viable and showed reduced incidence of age-associated pathologies, including obesity, inflammatory tissue degeneration, dysplasia, and spontaneous tumor formation. This was accompanied by global upregulation of oxidative phosphorylation and glycolysis transcriptomes, causing deregulated mitochondrial respiration, oxidative stress, impaired cell proliferation, and a switch to glycolytic metabolism in vivo. These data identify TRAP-1 as a central regulator of mitochondrial bioenergetics, and this pathway could contribute to metabolic rewiring in tumors.

A paradigm shift from anatomic to functional and molecular imaging in the detection of recurrent prostate cancer.

Approximately a third of men with localized prostate cancer who are treated with external beam radiation therapy (EBRT) or radical prostatectomy (RP) develop biochemical failure (BF). Presumably, BF will progress to distant metastasis and prostate cancer-specific mortality in some patients over subsequent years. Accurate detection of recurrent disease is important because it allows for appropriate treatment selection (e.g., local vs systemic therapy) and early delivery of therapy (e.g., salvage EBRT), which affect patient outcome. In this article, we discuss the paradigm shift in imaging technology in the detection of recurrent prostate cancer. First, we discuss the commonly used morphological and anatomical imaging modalities and their role in the post-RP and post-EBRT settings of BF. Second, we discuss the accuracy of functional and molecular imaging techniques, many of which are under investigation. Further studies are needed to establish the role of imaging techniques for detection of cancer recurrence and clinical decision-making.