HSP27, ALDH6A1 and Prohibitin Act as a Trio-biomarker to Predict Survival in Late Metastatic Prostate Cancer.

BACKGROUND/AIM: The aim of this study was to evaluate the usefulness of biomarkers related to prostate cancer metastasis and survival of patients. MATERIALS AND METHODS: Proteomics were used for detecting significant differences in protein expression among normal prostate, localized prostate cancer and metastatic cancer using 2-dimensional gel electrophoresis and mass spectrometry. mRNA expression was then examined in order to further confirm significant differences in protein expression. A total of 7 proteins were found to be differentially expressed. Immunochemistry (IHC), was also used to confirm the levels of expression of the 7 proteins in prostate cancer. Survival analysis using the candidate markers was finally performed in 98 metastatic prostate cancer patients according to IHC results. RESULTS: In metastatic lesions, proteomic analysis indicated that heat shock protein (HSP) 27, prohibitin, glutathione S-transferase 1, fibrinogen ß chain, and aldehyde dehydrogenase 6A1 were up-regulated, while α1 antitrypsin, and HSP 60 were down-regulated. IHC revealed that HSP 27, ALDH6A1 and prohibitin were highly specific to metastatic tumor cells. HSP27 and prohibitin appeared more strongly in the incipient stage of cancer than metastatic cancer, and ALDH6A1 was significantly reduced in metastatic cancer (p<0.01). Of all proteins, phohibitin had the highest value in predicting survival. However, all three proteins were a stronger marker than each one separately. CONCLUSION: Trio-biomarker composed of HSP27, ALDH6A1 and prohibitin may predict survival of metastatic prostate cancer patients.

The homeodomain-leucine zipper ATHB23, a phytochrome B-interacting protein, is important for phytochrome B-mediated red light signaling.

Phytochromes are red (R)/far-red (FR) photoreceptors that are central to the regulation of plant growth and development. Although it is well known that photoactivated phytochromes are translocated into the nucleus where they interact with a variety of nuclear proteins and ultimately regulate genome-wide transcription, the mechanisms by which these photoreceptors function are not completely understood. In an effort to enhance our understanding of phytochrome-mediated light signaling networks, we attempted to identify novel proteins interacting with phytochrome B (phyB). Using affinity purification in Arabidopsis phyB overexpressor, coupled with mass spectrometry analysis, 16 proteins that interact with phyB in vivo were identified. Interactions between phyB and six putative phyB-interacting proteins were confirmed by bimolecular fluorescence complementation (BiFC) analysis. Involvement of these proteins in phyB-mediated signaling pathways was also revealed by physiological analysis of the mutants defective in each phyB-interacting protein. We further characterized the athb23 mutant impaired in the homeobox protein 23 (ATHB23) gene. The athb23 mutant displayed altered hypocotyl growth under R light, as well as defects in phyB-dependent seed germination and phyB-mediated cotyledon expansion. Taken together, these results suggest that the ATHB23 transcription factor is a novel component of the phyB-mediated R light signaling pathway.

Proteomic molecular portrait of interface zone in breast cancer.

Surgical tumor margins are intended to encompass residual tumor cells but may not always accurately delineate the boundary between tumor and normal tissue. Efforts to define tumor margins based on molecular analysis have achieved limited success. Furthermore, no clinical trials have addressed the scope of the tumor microenvironment. Here, we considered the tumor cell population and surrounding microenvironment in delineating tumor margins, classifying breast cancer into tumor and normal zones, and introducing the concept of an interface zone, the region between the invading tumor front and normal tissue, which develops during tumor invasion and metastasis through remodeling of the tumor microenvironment. Pathological signatures of invasion markers in tumor tissues are most dynamic within the invading tumor front. We compared protein profiles of tumor, normal, and interface zones using MALDI-MS. Proteins upregulated in the interface zone were identified by peptide mass fingerprinting and confirmed by database searching with chemically assisted MALDI-PSD spectra. Upregulation was confirmed for RhoGDIα, CAPG, WDR1, and CK8 by Western and immunohistochemical analyses. Our results demonstrate that the molecular profile of the interface zone is unique and suggest that upregulation of proteins here may be related to progression and metastasis of breast carcinomas.

Panel of candidate biomarkers for renal cell carcinoma.

The timely diagnosis and therapeutic monitoring of human renal cell carcinoma (RCC) is limited by the lack of specific biomarkers. To identify candidate RCC biomarkers, we used 2-DE gel electrophoresis with mass spectrometry and 2-DE spot intensity-based ROC analysis to analyze 18 sets of paired normal and RCC tumor tissue including conventional, papillary, and chromophobe subtypes. Validation was performed with RCC patient plasma samples and confirmed by clustergram, shRNA, and immunohistochemistry assays. Cardinal candidates were evaluated by ELISA. The leading candidate biomarker that was upregulated in RCC samples according to the clustergram and validation analysis was nicotinamide N-methyltransferase (NNMT) (13/15, P < 0.0001). Other upregulated candidate biomarkers that were identified by this method include ferritin, hNSE, NM23, secretagogin, and L-plastin. The upregulation of NNMT in RCC was confirmed by immunoblotting and immunohistochemistry. Analysis of fractionated membrane-associated proteins identified CAP-G, mitofillin, tubulin alpha, RBBP7, and HSP27. Of these, RBBP7 and HSP27 were highly expressed in the chromophobe subtype of RCC (3/3) but were absent from conventional RCC (0/3). The triple combination of the NNMT, FTL, and hNSE biomarkers had the highest predictive capacity of 0.993, while NNMT was the single, most powerful candidate diagnostic biomarker for all types of RCC.

Proteomic pattern-based analyses of light responses in Arabidopsis thaliana wild-type and photoreceptor mutants.

Light critically affects the physiology of plants. Using two-dimensional gel electrophoresis, we used a proteomics approach to analyze the responses of Arabidopsis thaliana to red (660 nm), far-red (730 nm) and blue (450 nm) light, which are utilized by type II and type I phytochromes, and blue light receptors, respectively. Under specific light treatments, the proteomic profiles of 49 protein spots exhibited over 1.8-fold difference in protein abundance, significant at p <0.05. Most of these proteins were metabolic enzymes, indicating metabolic changes induced by light of specific wavelengths. The differentially-expressed proteins formed seven clusters, reflecting co-regulation. We used the 49 differentially-regulated proteins as molecular markers for plant responses to light, and by developing a procedure that calculates the Pearson correlation distance of cluster-to-cluster similarity in expression changes, we assessed the proteome-based relatedness of light responses for wild-type and phytochrome mutant plants. Overall, this assessment was consistent with the known physiological responses of plants to light. However, we also observed a number of novel responses at the proteomic level, which were not predicted from known physiological changes.