Herbimycin A, a tyrosine kinase inhibitor, induces cellular differentiation and delayed apoptosis in Colo-205 cells, a poorly differentiated human colon carcinoma cell line. Cell cycle analysis in conjunction with end labeling of DNA fragments revealed that G2 arrest preceded apoptotic cell death. Ultrastructural examination of herbimycin-treated cells demonstrated morphologic features of epithelial differentiation, including formation of a microvillar apical membrane and lateral desmosome adhesions. A marked accumulation of mitochondria was also observed. Fluorometric analysis using the mitochondrial probes nonyl-acridine orange and JC-1 confirmed a progressive increase in mitochondrial mass. However these cells also demonstrated a progressive decline in unit mitochondrial transmembrane potential (ΔΨm) as determined by the ΔΨm-sensitive fluorescent probes rhodamine 123 and JC-1 analyzed for red fluorescence. In concert with these mitochondrial changes, Colo-205 cells treated with herbimycin A produced increased levels of reactive oxygen species as evidenced by oxidation of both dichlorodihydrofluorescein diacetate and dihydroethidium. Cell-free assays for apoptosis using rat-liver nuclei and extracts of Colo-205 cells at 24 h showed that apoptotic activity of Colo-205 lysates requires the early action of mitochondria. Morphological and functional mitochondrial changes were observed at early time points, preceding cleavage of poly (ADP-ribose) polymerase. These results suggest that apoptosis in differentiated Colo-205 cells involves unrestrained mitochondrial proliferation and progressive membrane dysfunction, a novel mechanism in apoptosis.
Men are more frequently diagnosed with kidney cancer than women, with a more aggressive histology, larger tumors, a higher grade and stage, and worse oncological outcomes. Smoking habits and sex steroid hormones seem to have a possible role in explaining these gender disparities. Moreover, the expression of genes involved in tumor growth and immune response in kidney cancer varies between men and women, having an impact on the gender-related response to oncological therapy, such as anti-angiogenic drugs and immunotherapy. Recent advances have been made in our understanding of the molecular and genetic mechanisms involved in kidney cancer, which could partially explain the gender differences, and they are summarized in this paper. However, other key mechanisms, which fully clarify the striking clinical gender-related differences observed in kidney cancer, are not completely understood at present. We reviewed and summarized the most relevant publications about the relationship between gender and kidney cancer. Efforts should be made to progress in bench and clinical research on gender-related signatures and disparities, and their impact on the clinical management of kidney cancer.
Transitional cell carcinoma of the bladder is the second most common malignancy of the genitourinary tract. Cystoscopy and urine cytology are the traditional most used techniques for diagnosis and surveillance of superficial bladder cancer. Urine cytology is specific for diagnosis of bladder cancer but sensitivity results not high, particularly in low-grade disease. Voided urine can be easily obtained and therefore additional diagnostic urine tests would be ideal for screening or follow-up of transitional cell carcinoma. A number of studies have focused on the evaluation of urinary markers that hold promise as non-invasive adjuncts to conventional diagnostic or surveillance techniques. In this review we discuss several new urinary markers (test for bladder tumor antigen, NMP22®, fibrin degradation products, telomerase, fluorescence in situ hybridization test, flow cytometry) and their role in detection and follow-up of bladder cancer. Most of these markers have higher sensitivity than urine cytology, but voided urine cytology has the highest specificity.
Recently, there has been a great effort to develop tests based on non-invasive urinary biomarkers (NMIBCs). These tests are based on the fact that NMIBCs are heterogeneous at the molecular level and can be divided into different molecular groups useful to predict prognosis and response to treatment. The assessment of epigenetic alterations, such as DNA methylation, represents a promising cancer biomarker. DNA methylation is an epigenetic modification that affects gene expression without modifying the DNA sequence. Several studies have highlighted the presence of methylated loci in the context of bladder cancer, indicating its potential application as a diagnostic and prognostic biomarker. One of the novel assays based on a DNA methylation profile, the Bladder EpiCheck, analyzes DNA from spontaneous urine, detecting disease-specific DNA methylation patterns in bladder cancer patients. This test, due to its non-invasive nature and highly promising performance could, in future, become an invaluable tool in the follow-up of bladder cancer patients. Potential new applications could include diagnosis and surveillance of upper-tract disease, for the replacement of invasive testing and ureteroscopy.