The clinical and therapeutic uses of MDM2 and PSMA and their potential interaction in aggressive cancers

Advances in Molecular Regulation of Prostate Cancer Cells by Top Natural Products of Malaysia

Prostate cancer (PCa) remains both a global health burden and a scientific challenge. We present a review of the molecular targets driving current drug discovery to fight this disease. Moreover, the preventable nature of most PCa cases represents an opportunity for phytochemicals as chemopreventive when adequately integrated into nutritional interventions. With a renovated interest in natural remedies as a commodity and their essential role in cancer drug discovery, Malaysia is looking towards capitalizing on its mega biodiversity, which includes the oldest rainforest in the world and an estimated 1200 medicinal plants. We here explore whether the list of top Malay plants prioritized by the Malaysian government may fulfill the potential of becoming newer, sustainable sources of prostate cancer chemotherapy. These include Andrographis paniculate, Centella asiatica, Clinacanthus nutans, Eurycoma longifolia, Ficus deltoidea, Hibiscus sabdariffa, Marantodes pumilum (syn. Labisia pumila), Morinda citrifolia, Orthosiphon aristatus, and Phyllanthus niruri. Our review highlights the importance of resistance factors such as Smac/DIABLO in cancer progression, the role of the CXCL12/CXCR4 axis in cancer metastasis, and the regulation of PCa cells by some promising terpenes (andrographolide, Asiatic acid, rosmarinic acid), flavonoids (isovitexin, gossypin, sinensetin), and alkylresorcinols (labisiaquinones) among others.

Prostate-specific membrane antigen expression predicts recurrence of papillary thyroid carcinoma after total thyroidectomy

BACKGROUND

Prostate-specific membrane antigen (PSMA) overexpression has been observed in the endothelial neovasculature of several solid malignancies. This study aimed to identify PSMA expression in the primary tumor of classical papillary thyroid carcinoma (PTC) and assess the correlation between the degree of PSMA expression and recurrence.

METHODS

We reviewed the electronic medical records of patients who underwent total thyroidectomy and central neck dissection, with or without lateral neck dissection, for classical PTC between 2009 and 2014 at our institution. Recurrence was defined as a structural disease based on histological confirmation on follow-up. Fifty-one patients with the recurrent structural disease were matched, using a propensity score matching method, to patients with no disease evidence during follow-up. Clinicopathological and follow-up data were collected for 102 patients. The monoclonal mouse anti-human PSMA/FOLH1/NAALADase I antibody was used for staining the primary tumor. The score of PSMA expression was classified as negative (< 5% positivity), weak (5-10 % positivity), moderate (11-49% positivity), and strong (more than 50% positivity). Clinicopathological factors were compared between patients with low and high PSMA expression. Moreover, whether the degree of PSMA expression and clinicopathological factors could predict recurrence was investigated. Cox proportional hazard regression models were used to evaluate the risk of recurrence.

RESULTS

There was no significant difference in clinicopathological factors between low (negative or weak) and high (moderate or strong) PSMA expression. Gross extrathyroidal extension (ETE), absence of chronic lymphocytic thyroiditis, and high PSMA expression were all associated with lower recurrence-free survival (RFS) rate in a univariate analysis. In multivariate analysis, gross ETE (hazard ratio [HR], 2.279; 95% confidence interval [CI], 1.257-4.132; p = 0.007) and high PSMA expression (HR, 1.895; 95% CI, 1.073-3.348; p = 0.028) were associated with poor RFS.

CONCLUSIONS

High PSMA expression in the primary tumor was a significant factor in predicting recurrence in classic PTC. PSMA could be a potential biomarker for personalized management for PTC.

Expression of prostate-specific membrane antigen in the neovasculature of primary tumors and lymph node metastasis of laryngeal squamous cell carcinomas

Background

Prostate-specific membrane antigen (PSMA) expression is encountered in tumor-associated neovascularization.

Methods

PSMA-antibody was applied to the paraffin blocks of 51 patients who were diagnosed with squamous cell carcinoma of the larynx and underwent laryngectomy and one who underwent lymph node dissection. The percentage of vascular expression in tumoral and extratumoral stroma and lymph nodes and intensity score in tumoral epithelium were evaluated and divided into groups according to the level of PSMA expression. Final PSMA expression was determined by multiplying intensity and percentage scores.

Results

The mean age was 61±10 years. Patients with perineural invasion, cartilage invasion, and local invasion exhibited higher PSMA expression scores. Age, tumor differentiation, tumor diameter, perineural invasion, tumor localization, capsular invasion, depth of invasion, surgical margin status, local invasion, nodal metastasis, TNM classification, and stage were similar in high and low PSMA expression groups. There was no PSMA expression in extratumoral vascular stroma. Significantly higher PSMA expression was observed in the vascular endothelium of metastatic lymph nodes compared with reactive lymph nodes. Patients with advanced-stage disease exhibited higher PSMA vascular expression scores compared to those with earlier stages (p<.001). PSMA expression was not correlated with overall survival, disease-specific survival, or disease-free survival (p>.05).

Conclusions

Our study suggests that higher PSMA expression is associated with cartilage invasion, local invasion, and advanced-stage of disease. PSMA expression can be utilized for detection of lymph node metastasis and has some predictive role in cases of neck metastasis.

VEGF-A/VEGF-B/VEGF-C expressions in non-hereditary, non-metastatic phaeochromocytoma

Vascular endothelial growth factor (VEGF) is important in pathogenesis of different cancers. The aim of this study is to investigate the relationships between different VEGFs and clinicopathological factors in patients with phaeochromocytomas. Twenty patients (10 men; 10 women) with non-hereditary, non-metastatic phaeochromocytomas were examined for VEGF mRNA expressions by polymerase chain reaction. The expressions were correlated with the clinical and pathological factors of the patients. In addition, mouse double minute 2 (MDM2) expression in these tumours were studied by immunohistochemistry. High expressions of VEGF-A, VEGF-B, and VEGF-C mRNA were detected in 11 (55%), 9 (45%), and 9 (45%) of the tumours respectively. High expression of VEGF-A in phaeochromocytomas was significantly correlated with the tumour size (p=0.025) but did not correlate with patients' age, gender, and tumour laterality. Besides, there was a trend of VEGF-A expression correlated with MDM2 expression (p=0.064). On the other hand, expressions of VEGF-B and VEGF-C were not significantly correlated with tumour size, patients' age, gender, tumour laterality, and MDM2 expression. In addition, high expressions of VEGF-B and VEGF-A were associated with increase of tumour size (p=0.042). Co-expression of different VEGFs did not correlate with MDM2 expression. To conclude, there is a role for VEGF-A/VEGF-B/VEGF-C in the pathogenesis of non-hereditary, non-metastatic phaeochromocytomas.