Development of noninvasive methods for the diagnosis of transitional cell carcinoma (TCC) of the bladder remains a challenge. A ProteinChip technology (sur-faceBladder cancer is the second most common genitourinary malignancy accounting for ϳ5% of all newly diagnosed cancers in the United States. 1 More than 90% are of the transitional cell carcinoma (TCC) histology. 2 At present, the most reliable way of diagnosis and surveillance of TCC is by cystoscopic examination and bladder biopsy for histological confirmation. The invasive and labor-intensive nature of this procedure presents a challenge to develop better, less costly, and noninvasive diagnostic tools. Urine cytology has for many years been the gold standard of the noninvasive approaches. It has high specificity and provides the advantage over biopsy of screening the entire urothelium. 2,3 However, its high false-negative rate, particularly for low-grade tumors, has limited its use as an adjunct to cystoscopy.Many noninvasive molecular diagnostic tests have been developed based on an ever-increasing knowledge about the molecular alterations associated with bladder cancer pathogenesis. The bladder tumor antigen, 4 the bladder tumor antigen stat, 5 the fibrinogen/fibrin degradation products, 6 and the nuclear matrix protein-22 tests, 3,7 have been approved by the Food and Drug Administration to be used in conjunction with cystoscopy. Additional molecular assays currently being evaluated for their diagnostic/prognostic utility 2,3,8,9 are the Telomerase, 10
Purpose: Histopathology is the standard approach for tissue diagnostics and centerpiece of pathology. Although the current system provides prognostic information, there is need for molecular markers that enhance diagnosis and better predict clinical prognosis. The ability to localize disease-specific molecular changes in biopsy tissue would help improve critical pathology decision making. Direct profiling of proteins from tissue using matrix-assisted laser desorption/ionization imaging mass spectrometry has the potential to supplement morphology with underlying molecular detail. Experimental Design: A discovery set of 11 prostate cancer (PCa)–containing and 10 benign prostate tissue sections was evaluated for protein expression differences. A separate validation set of 54 tissue sections (23 PCa and 31 benign) was used to verify the results. Cryosectioning was done to yield tissue sections analyzed by a pathologist to determine tissue morphology and mirror sections for imaging mass spectrometry. Spectra were acquired and the intensity of signals was plotted as a function of the location within the tissue. Results: An expression profile was found that discriminates between PCa and normal tissue. The overexpression of a single ion at m/z 4,355 was able to discriminate cancer from uninvolved tissue. Tandem mass spectrometry identified this marker as a fragment of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 2 (MEKK2). The ability of MEKK2 to discriminate tumor from normal cells was orthogonally confirmed. Conclusions: This study highlights the potential of this approach to uncover molecular detail that can be correlated with pathology decision making. In addition, the identification of MEKK2 shows the ability to discover proteins of relevance to PCa biology. (Clin Cancer Res 2009;15(17):5541–51)
There are fundamental histological differences between detected and missed prostate tumors using magnetic resonance imaging. Insights into these differences may facilitate the prospective role of magnetic resonance imaging in counseling and treatment selection for patients with prostate cancer.
Autophagy is an intracellular pathway for the degradation of long-lived proteins and damaged organelles. It is, in essence, a recycling process allowing cells to survive oxygen and nutrient depletion. The expression of two autophagy-related proteins, beclin 1 and light chain 3A (LC3A) was investigated in 79 nodular cutaneous melanomas. The results were correlated with histopathological factors, vascular density, and hypoxia-related proteins [hypoxia-inducible factors (HIF1α and HIF2α) and lactate dehydrogenase 5]. The reactivity of both autophagy-related proteins was uniformly cytoplasmically diffused. High beclin 1 and LC3A reactivity was related to tumor hypoxia, as this was inferred from the intense expression of HIF1α and lactate dehydrogenase 5, whereas low beclin 1 and LC3A expression was linked with an increased vascular density. In addition, beclin 1 was related to disease-specific survival which, however, exposed a biphasic pattern. A strong beclin 1 expression extending over a tumor area of more than 50% (high) was associated with an increased rate of early deaths, whereas a similarly strong, but less-extensive cytoplasmic reactivity (<10% tumor area; low) defined a sharp fall in the survival 5 years after surgery. Furthermore, the low beclin 1 expression was associated with high Breslow's depth, high Clark's level, and ulceration. Low LC3A expression was also related to ulceration, but not to other histopathological features nor prognosis. In multivariate analysis, beclin 1 was an independent prognostic variable. It is concluded that extensive autophagic activity is generated by tumor hypoxia and anaerobic glycolysis, whereas angiogenesis maintains low autophagic activity. Atg6/beclin 1 was proved to be capable of deciphering the prognosis in cutaneous malignant melanoma, but the matter requires further investigation.
Tumor-associated stroma (TAS) is not simply a supporting element for cancer cells, but plays an important role in tumor growth, invasion and metastasis. Changes on the level of stromal constituents, such as loss of Caveolin-1 and increased thymidine phosphorylase (TP) expression, have been associated with tumor aggressiveness. The mutual cooperation between stromal fibroblasts and cancer cells is another distinguishing feature, which has recently emerged. In this investigation, both the loss of Caveolin-1 and the increased TP expression in the prostatic TAS was associated with high Gleason score (p = 0.0002 and 0.003, respectively); the two proteins were acting both independently and synergistically. In addition, TP was significantly associated with high stromal Ki-67 (MIB1) proliferation index (p = 0.03). Analysis of the metabolic interactions between stromal and epithelial elements showed that, while prostatic cancer cells express principally (> 91%) lactate dehydrogenase-5 (LDH-5) (anaerobic metabolism), the tumor-associated fibroblasts/myofibroblasts (TAFs) express largely (67.8%) LDH-1 (aerobic metabolism)-the terms TAFs and TAS are used interchangeably. These two isoenzyme pathways act complementary; the LDH-5 pathway converts pyruvate to lactate, whereas the LDH-1 enzyme system utilizes the secreted metabolite lactate to produce pyruvate, essential for continuous energy supply to tumor cells. Monocarboxylate transporter-1 (MCT-1)-the main facilitator of lactate uptake in tumor cells, was expressed exclusively in prostate cancer cells and related directly to LDH-5 overexpression. These findings support and extend our previous studies on energy recycling between the aerobic stroma and the anaerobic cancer cells within the framework of Warburg effect.
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