Upstream molecular signaling pathways of p27(Kip1) expression in human breast cancer cells in vitro: differential effects of 4-hydroxytamoxifen and deficiency of either D-(+)-glucose or L-leucine

Background

The objective of this study was to investigate whether the levels of glucose or certain amino acids could regulate the expression of a cell cycle repressor protein p27(Kip1), thereby dictating the risk of cancer in either obesity or caloric/dietary restriction. Previously, we identified and reported four different upstream molecular signaling pathways of p27 expression in human breast cancer cells. We called these four pathways as pathway #1, #2, #3 and #4. We found that 4-hydroxytamoxifen - but not tamoxifen - up-regulated the expression of p27 using pathway #1 which consisted mainly of receptor tyrosine kinases and mTORC1. We now investigate, using 4-hydroxytamoxifen as a reference anti-cancer agents, whether (a) the moderate increase in the concentration of D-(+)-glucose could down-regulate and, conversely, (b) the deficiency of D-(+)-glucose or certain L-amino acids could up-regulate the expression of p27 in these cells using pathway #2 which consists mainly of AMPK and mTORC1.

Results

Using human MDA-MB-231 breast cancer cells in vitro, these hypotheses were tested experimentally by performing p27-luciferase reporter transfection assays and western immunoblot analyses. The results obtained are consistent with these hypotheses. Furthermore, the results indicated that, although 4-hydroxytamoxifen used primarily pathway #1 to down-regulate the phosphorylation of 4E-BP1 and up-regulate the expression of p27, it also secondarily down-regulated the phosphorylation of S6K1. In contrast, the deficiency of D-(+)-glucose or L-leucine used primarily pathway #2 to down-regulate the phosphorylation of S6K1, but they also secondarily down-regulated the phosphorylation of 4E-BP1 and up-regulated the expression of p27. Finally, deficiency of D-(+)-glucose or L-leucine - but not 4-hydroxytamoxifen - up-regulated the expression of mitochondrial ATP5A and SIRT3.

Conclusions

(a) 4-Hydroxitamoxifen used primarily pathway #1 to up-regulate the expression of p27. (b) Moderate increase in the concentration of D-(+)-glucose used primarily pathway #2 to down-regulate the expression of p27. (c) Deficiency of D-(+)-glucose or L-leucine also used primarily pathway #2 to up-regulate the expression of p27. (d) Deficiency of D-(+)-glucose or L-leucine - but not 4-hydroxytamoxifen - up-regulated the expression of mitochondrial ATP5A in the Complex V of respiratory oxidation-phosphorylation chain and mitochondrial SIRT3. The SIRT3 is one of the seven mammalian anti-aging as well as anti-metabolic sirtuins.     

External jugular vein cutdown approach for chronic indwelling central venous access in cancer patients: A potentially useful alternative

Background

Survival in colorectal cancer may correlate with the degree of systemic inflammatory response to the tumour. Atrial fibrillation may be regarded as an inflammatory complication. We aimed to determine if atrial fibrillation is a prognostic factor in colorectal cancer.

Patients and methods

A prospective colorectal cancer patient database was cross-referenced with the hospital clinical-coding database to identify patients who had underwent colorectal cancer surgery and were in atrial fibrillation pre- or postoperatively.

Results

A total of 175 patients underwent surgery for colorectal cancer over a two-year period. Of these, 13 patients had atrial fibrillation pre- or postoperatively. Atrial fibrillation correlated with worse two-year survival (p = 0.04; log-rank test). However, in a Cox regression analysis, atrial fibrillation was not significantly associated with survival.

Conclusion

The presence or development of atrial fibrillation in patients undergoing surgery for colorectal cancer is associated with worse overall survival, however it was not found to be an independent factor in multivariate analysis.     

Diagnostic utility of snail in metaplastic breast carcinoma

Aims

As one of the five Lactate dehydrogenase (LDH) isoenzymes, LDH5 has the highest efficiency to catalyze pyruvate transformation to lactate. LDH5 overexpression in cancer cells induces an upregulated glycolytic metabolism and reduced dependence on the presence of oxygen. Here we analyzed LDH5 protein expression in a well characterized large cohort of primary lung cancers in correlation to clinico-pathological data and its possible impact on patient survival.

Methods

Primary lung cancers (n = 269) and non neoplastic lung tissue (n = 35) were tested for LDH5 expression by immunohistochemistry using a polyclonal LDH5 antibody (ab53010). The results of LDH5 expression were correlated to clinico-pathological data as well as to patient's survival. In addition, the results of the previously tested Transketolase like 1 protein (TKTL1) expression were correlated to LDH5 expression.

Results

89.5% (n = 238) of NSCLC revealed LDH5 expression whereas LDH5 expression was not detected in non neoplastic lung tissues (n = 34) (p < 0.0001). LDH5 overexpression was associated with histological type (adenocarcinoma = 57%, squamous cell carcinoma = 45%, large cell carcinoma = 46%, p = 0.006). No significant correlation could be detected with regard to TNM-stage, grading or survival. A two sided correlation between the expression of TKTL1 and LDH5 could be shown (p = 0.002) within the overall cohort as well as for each grading and pN group. A significant correlation between LDH5 and TKTL1 within each histologic tumortype could not be revealed.

Conclusions

LDH5 is overexpressed in NSCLC and could hence serve as an additional marker for malignancy. Furthermore, LDH5 correlates positively with the prognostic marker TKTL1. Our results confirm a close link between the two metabolic enzymes and indicate an alteration in the glucose metabolism in the process of malignant transformation.     

The stem cell factor antibody enhances the chemotherapeutic effect of adriamycin on chemoresistant breast cancer cells

Background

The outcome of chemotherapy in breast cancer is strongly influenced by multidrug resistance (MDR). Several surrogate markers of chemoresistance have been identified including - CD24 (cluster differentiation 24) expression, stem cell growth factor (SCF), B-cell lymphocyte protein 2 (Bcl-2) and annexin V. The present study aimed to examine the expression of CD24 in the sensitive breast cancer cell line MCF-7 (Michigan Foudation-7) and MCF-7/adriamycin resistant (MCF-7/AdrRes) cells, and, if minimal effective doses of the anthracycline drug adriamycin (0.579???M and 88.2???M) would be enhanced by the antibody to SCF (anti-SCF).

Methods

CD24 expression was analysed by flow cytometry. Both Bcl-2 and annexin V protein expression were quantitatively assessed by the enzyme-linked immunosorbent assay (ELISA).

Results

In MCF-7/AdrRes cells the expression of CD24 was significantly higher compared to MCF-7 cells, 86.6% and 16.3% (p?Conclusion Adding anti-SCF to the chemotherapeutic regime of adriamycin may strongly enhance its chemotherapeutic effect in the treatment of patients with breast cancer.     

Effector granules in human T lymphocytes: the luminal proteome of secretory lysosomes from human T cells

Background

The incidence of cancer in patients with neurological diseases, who have been treated with LiCl, is below average. LiCl is a well-established inhibitor of Glycogen synthase kinase-3, a kinase that controls several cellular processes, among which is the degradation of the tumour suppressor protein p53. We therefore wondered whether LiCl induces p53-dependent cell death in cancer cell lines and experimental tumours.

Results

Here we show that LiCl induces apoptosis of tumour cells both in vitro and in vivo. Cell death was accompanied by cleavage of PARP and Caspases-3, -8 and -10. LiCl-induced cell death was not dependent on p53, but was augmented by its presence. Treatment of tumour cells with LiCl strongly increased TNF-α and FasL expression. Inhibition of TNF-α induction using siRNA or inhibition of FasL binding to its receptor by the Nok-1 antibody potently reduced LiCl-dependent cleavage of Caspase-3 and increased cell survival. Treatment of xenografted rats with LiCl strongly reduced tumour growth.

Conclusions

Induction of cell death by LiCl supports the notion that GSK-3 may represent a promising target for cancer therapy. LiCl-induced cell death is largely independent of p53 and mediated by the release of TNF-α and FasL. Key words: LiCl, TNF-α, FasL, apoptosis, GSK-3, FasL     

Identification of prognostic factors in canine mammary malignant tumours: a multivariable survival study

Background

Although several histopathological and clinical features of canine mammary gland tumours have been widely studied from a prognostic standpoint, considerable variations in tumour individual biologic behaviour difficult the definition of accurate prognostic factors. It has been suggested that the malignant behaviour of tumours is the end result of several alterations in cellular physiology that culminate in tumour growth and spread. Accordingly, the aim of this study was to determine, using a multivariable model, the independent prognostic value of several immunohistochemically detected tumour-associated molecules, such as MMP-9 and uPA in stromal cells and Ki-67, TIMP-2 and VEGF in cancer cells.

Results

Eighty-five female dogs affected by spontaneous malignant mammary neoplasias were followed up for a 2-year post-operative period. In univariate analysis, tumour characteristics such as size, mode of growth, regional lymph node metastases, tumour cell MIB-1 LI and MMP-9 and uPA expressions in tumour-adjacent fibroblasts, were associated with both survival and disease-free intervals. Histological type and grade were related with overall survival while VEGF and TIMP-2 were not significantly associated with none of the outcome parameters. In multivariable analysis, only a MIB-1 labelling index higher than 40% and a stromal expression of MMP-9 higher than 50% retained significant relationships with poor overall and disease-free survival.

Conclusions

The results of this study indicate that MMP-9 and Ki-67 are independent prognostic markers of canine malignant mammary tumours. Furthermore, the high stromal expressions of uPA and MMP-9 in aggressive tumours suggest that these molecules are potential therapeutic targets in the post-operative treatment of canine mammary cancer.     

Expression of Placenta growth factor (PlGF) in non-Small cell Lung cancer (NSCLC) and the clinical and prognostic significance

Background

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family. Over-expression of PlGF is known to be associated with pathological angiogenesis. This study examined PlGF expression at protein and message levels in non-small cell lung cancer (NSCLC), in which no reports on the significance of PlGF expression is available to date.

Patients and methods

We used immunohistochemistry to assess the PlGF protein and correlated PlGF with microvessel density (MVD), as well as clinical outcome in patients with NSCLC tumours (n = 91). In addition, we applied a real time quantitative PCR assay using SYBR Green chemistry to measure PlGF mRNA in normal lung tissues and NSCLC tumours.

Results

PlGF was positively stained mainly in cytoplasm of lung cancer cells. High level staining of PlGF was found in 38.5% NSCLC patients. A high level of MVD in NSCLC was found in 42.9% of cases. Tumours with high level and low level PlGF staining had a significantly different MVD (26.69 vs. 20.79, respectively, p = 0.003). Using both univariate and multivariate analyses, PlGF was found to be an independent prognostic factor. Real time PCR analysis revealed that PlGF mRNA was higher in the cancer tissue than normal tissue (0.95 ± 0.19 vs. 0.57 ± 0.24; p < 0.005) and that PlGF mRNA was significant higher in III-IV stage patients than in I-II stage patients (1.03 ± 0.20 vs. 0.80 ± 0.17; p = 0.011).

Conclusion

PlGF expression is significantly more in NSCLC tumour tissues than in matched normal tissues. It has a significant positive association with MVD and is an independent factor for NSCLC patients. PlGF may have a pivotal role in NSCLC development and disease progression.     

Identification of differentially expressed proteins in spontaneous thymic lymphomas from knockout mice with deletion of p53

Background

Knockout mice with a deletion of p53 spontaneously develop thymic lymphomas. Two cell lines (SM5 and SM7), established from two independent tumours, exhibited about fifty to seventy two-fold differentially expressed proteins compared to wild type thymocytes by two-dimensional gel electrophoresis (2D-PAGE).

Results

Protein spots excised from 2D-PAGE gels, were subjected to in-gel tryptic digestion and identified by liquid chromatography – tandem mass spectrometry. A total of 47 protein spots were identified. Immunological verification was performed for several of the differentially regulated proteins where suitable antibodies could be obtained. Functional annotation clustering revealed similarities as well as differences between the tumours. Twelve proteins that changed similarly in both tumours included up-regulation of rho GDP-dissociation inhibitor 2, proteasome subunit α type 3, transforming acidic coiled-coil containing protein 3, mitochondrial ornithine aminotransferase and epidermal fatty acid binding protein and down-regulation of adenylosuccinate synthetase, tubulin β-3 chain, a 25 kDa actin fragment, proteasome subunit β type 9, cofilin-1 and glia maturation factor γ.

Conclusion

Some of the commonly differentially expressed proteins are also differentially expressed in other tumours and may be putative diagnostic and/or prognostic markers for lymphomas.     

Vulvar squamous cell carcinoma with sarcoma-like stroma: A case report and review of the literature

Background

The importance of cell-cell junction proteins (including armadillo proteins) in tumor biology is known, but limited with regard to plakophilins. We explored the relationship between plakophilins (PKP1, PKP2, PKP3) to gastric cancer via immunohistochemical techniques.

Methods

We compared the immunohistochemistry of PKPs in 34 gastric adenocarcinomas and 20 normal gastric tissues.

Results

In gastric cancer, PKP1 expression was unchanged but PKP2 and PKP3 were significantly decreased as compared to normal controls. There was no observable clinical association with PKP1 or PKP2 expression; however, low PKP3 level and poor prognosis appeared to correlate with regards to node number and tumor stage. The mean disease-free survival (DFS) was 38 ± 3 months (range: 32 - 44) and mean overall survival (OS) 42 ± 4 months (range: 38 - 50). Decreased PKP2 appeared to negatively impact DFS.

Conclusion

Decreased PKP2 and PKP3 may be early prognostic markers and loss of PKP3 expression during gastric carcinoma progression may indicate an invasive phenotype.     

Probing the link between oestrogen receptors and oesophageal cancer

Background

Elevated pre-operative neutrophil: lymphocyte ratio (NLR) has been identified as a predictor of survival in patients with hepatocellular and colorectal cancer. The aim of this study was to examine the prognostic value of an elevated preoperative NLR following resection for oesophageal cancer.

Methods

Patients who underwent resection for oesophageal carcinoma from June 1997 to September 2007 were identified from a local cancer database. Data on demographics, conventional prognostic markers, laboratory analyses including blood count results, and histopathology were collected and analysed.

Results

A total of 294 patients were identified with a median age at diagnosis of 65.2 (IQR 59-72) years. The median pre-operative time of blood sample collection was three days (IQR 1-8). The median neutrophil count was 64.2 × 10^-9/litre, median lymphocyte count 23.9 × 10^-9/litre, whilst the NLR was 2.69 (IQR 1.95-4.02). NLR did not prove to be a significant predictor of number of involved lymph nodes (Cox regression, p = 0.754), disease recurrence (p = 0.288) or death (Cox regression, p = 0.374). Furthermore, survival time was not significantly different between patients with high (≥ 3.5) or low (< 3.5) NLR (p = 0.49).

Conclusion

Preoperative NLR does not appear to offer useful predictive ability for outcome, disease-free and overall survival following oesophageal cancer resection.     

Immunohistochemistry profiles of breast ductal carcinoma: factor analysis of digital image analysis data

Background

Molecular studies of breast cancer revealed biological heterogeneity of the disease and opened new perspectives for personalized therapy. While multiple gene expression-based systems have been developed, current clinical practice is largely based upon conventional clinical and pathologic criteria. This gap may be filled by development of combined multi-IHC indices to characterize biological and clinical behaviour of the tumours. Digital image analysis (DA) with multivariate statistics of the data opens new opportunities in this field.

Methods

Tissue microarrays of 109 patients with breast ductal carcinoma were stained for a set of 10 IHC markers (ER, PR, HER2, Ki67, AR, BCL2, HIF-1??, SATB1, p53, and p16). Aperio imaging platform with the Genie, Nuclear and Membrane algorithms were used for the DA. Factor analysis of the DA data was performed in the whole group and hormone receptor (HR) positive subgroup of the patients (n = 85).

Results

Major factor potentially reflecting aggressive disease behaviour (i-Grade) was extracted, characterized by opposite loadings of ER/PR/AR/BCL2 and Ki67/HIF-1??. The i-Grade factor scores revealed bimodal distribution and were strongly associated with higher Nottingham histological grade (G) and more aggressive intrinsic subtypes. In HR-positive tumours, the aggressiveness of the tumour was best defined by positive Ki67 and negative ER loadings. High Ki67/ER factor scores were strongly associated with the higher G and Luminal B types, but also were detected in a set of G1 and Luminal A cases, potentially indicating high risk patients in these categories. Inverse relation between HER2 and PR expression was found in the HR-positive tumours pointing at differential information conveyed by the ER and PR expression. SATB1 along with HIF-1?? reflected the second major factor of variation in our patients; in the HR-positive group they were inversely associated with the HR and BCL2 expression and represented the major factor of variation. Finally, we confirmed high expression levels of p16 in Triple-negative tumours.

Conclusion

Factor analysis of multiple IHC biomarkers measured by automated DA is an efficient exploratory tool clarifying complex interdependencies in the breast ductal carcinoma IHC profiles and informative value of single IHC markers. Integrated IHC indices may provide additional risk stratifications for the currently used grading systems and prove to be useful in clinical outcome studies.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1512077125668949     

Global gene expression profiles of canine macrophages and canine mammary cancer cells grown as a co-culture in vitro

Background

Solid tumours comprise various cells, including cancer cells, resident stromal cells, migratory haemopoietic cells and other. These cells regulate tumour growth and metastasis. Macrophages constitute probably the most important element of all interactions within the tumour microenvironment. However, the molecular mechanism, that guides tumour environment, still remains unknown. Exploring the underlying molecular mechanisms that orchestrate these phenomena has been the aim of our study. A co-culture of canine mammary cancer cells and macrophages was established and maintained for 72 hrs. Having sorted the cells, gene expression in cancer cells and macrophages, using DNA microarrays, was examined. The results were confirmed using real-time qPCR and confocal microscopy. Moreover, their ability for migration and invasion has been assessed.

Results

Microarray analysis showed that the up-regulated genes in the cancer cell lines are involved in 15 highly over-manifested pathways. The pathways that drew our diligent attention included: the inflammation pathway mediated by chemokine and cytokine, the Toll receptor signalling pathway and the B cell activation. The up-regulated genes in the macrophages were involved in only 18 significantly over-manifested pathways: the angiogenesis, the p53 pathway feedback loops2 and the Wnt signalling pathway. The microarray analysis revealed that co-culturing of cancer cells with macrophages initiated the myeloid-specific antigen expression in cancer cells, as well as cytokine/chemokine genes expression. This finding was confirmed at mRNA and protein level. Moreover, we showed that macrophages increase cancer migration and invasion.

Conclusions

The presence of macrophages in the cancer environment induces acquisition of the macrophage phenotype (specific antigens and chemokines/cytokines expression) in cancer cells. We presumed that cancer cells also acquire other myeloid features, such as: capabilities of cell rolling, spreading, migration and matrix invasion (what has also been confirmed by our results). It may, perhaps, be the result of myeloid-cancer cell hybrid formation, or cancer cells mimicking macrophages phenotype, owing to various proteins secreted by macrophages.     

Surgical outcomes for colon and rectal cancer over a decade: results from a consecutive monocentric experience in 902 unselected patients

Background

This study evaluates the surgical morbidity and long-term outcome of colorectal cancer surgery in an unselected group of patients treated over the period 1994–2003.

Methods

A consecutive series of 902 primary colorectal cancer patients (489 M, 413 F; mean age: 63 years ± 11 years, range: 24–88 years) was evaluated and prospectively followed in a university hospital (mean follow-up 36 ± 24 months; range: 3–108 months). Perioperative mortality, morbidity, overall survival, curative resection rates, recurrence rates were analysed.

Results

Of the total, 476 colorectal cancers were localized to the colon (CC, 53%), 406 to the rectum (RC, 45%), 12 (1%) were multicentric, and 8 were identified as part of HNPCC (1%). Combining all tumours, there were 186 cancers (20.6%) defined as UICC stage I, 235 (26.1%) stage II, 270 (29.9%) stage III and 187 (20.6%) stage IV cases. Twenty-four (2.7%) cases were of undetermined stage. Postoperative complications occurred in 38% of the total group (37.8% of CC cases, 37.2% of the RC group, 66.7% of the synchronous cancer patients and 50% of those with HNPCC, p = 0.19) Mortality rate was 0.8%, (1.3% for colon cancer, 0% for rectal cancer; p = 0.023). Multivisceral resection was performed in 14.3% of cases. Disease-free survival in cases resected for cure was 73% at 5-years and 72% at 8 years. The 5- and 8-year overall survival rates were 71% and 61% respectively (total cases). At 5-year analysis, overall survival rates are 97% for stage I disease, 87% for stage II, 73% for stage III and 22% for stage IV respectively (p < 0.0001). The 5-year overall survival rates showed a marked difference in R0, R1+R2 and non resected patients (82%, 35% and 0% respectively, p < 0.0001). On multivariate analysis, resection for cure and stage at presentation but not tumour site (colon vs. rectum) were independent variables for overall survival (p < 0.0001).

Conclusion

A prospective, uniform follow-up policy used in a single institution over the last decade provides evidence of quality assurance in colorectal cancer surgery with high rates of resection for cure where only stage at presentation functions as an independent variable for cancer-related outcome.     

Contributions of differential p53 expression in the spontaneous immortalization of a chicken embryo fibroblast cell line

Background

The present study was carried out to determine whether the p53 pathway played a role in the spontaneous immortalization of the SC-2 chicken embryo fibroblast (CEF) cell line that has been in continuous culture for over three years.

Results

The SC-2 cell line emerged from an extended crisis period with a considerably slower growth rate than primary CEF cells. The phenotype of the SC-2 cells changed dramatically at about passage 80, appearing smaller than at earlier passages (e.g., passage 43) and possessing a small, compact morphology. This morphological change coincided with an increase in growth rate. Passage 43 SC-2 cells expressed undetectable levels of p53 mRNA, but by passage 95, the levels were elevated compared to primary passage 6 CEF cells and similar to levels in senescent CEF cells. However, the high level of p53 mRNA detected in passage 95 SC-2 cells did not correlate to functional protein activity. The expression levels of the p53-regulated p21^WAF1 gene were significantly decreased in all SC-2 passages that were analyzed. Examination of the Rb pathway revealed that E2F-1 and p15^INK4b expression fluctuated with increasing passages, with levels higher in passage 95 SC-2 cells compared to primary passage 6 CEF cells.

Conclusion

The present study suggests that altered expression of genes involved in the p53 and Rb pathways, specifically, p53 and p21^WAF1, may have contributed to the immortalization of the SC-2 CEF cell line.     

Diffuse large B-cell lymphoma presenting with neurolymphomatosis and intravascular lymphoma: a unique autopsy case with diverse neurological symptoms

Background

The diagnosis of uterine smooth muscle tumors depends on a combination of microscopic features. However, a small number of these tumors still pose difficult diagnostic challenges.

Aim

To investigate progesterone receptor (PR) and p53 expression in leiomyomas (LMs), atypical leiomyomas (ALMs), smooth muscle tumors of uncertain malignant potential (STUMP), and leiomyosarcomas (LMSs) and to evaluate the potential utility of the selected immunohistochemical markers in differentiating these tumors.

Materials and methods

Immunohistochemical expression of PR and p53 was investigated in 41 uterine smooth muscle tumors comprising: 15 LMS, 4 STUMP, 6 ALM and 16 LM. Quantitative evaluation of PR and p53 expression was graded on a scale from 0 to 3+.

Results

Leiomyosarcomas showed reduced PR expression. All LMs as well as ALMs and STUMP were stained intensely for PR. Conversely, LMS was strongly stained with p53, while the three non-sarcomatous groups (STUMP, ALM, LM) were either entirely negative or weakly stained for p53. Regarding both PR and p53 expression, the difference between the LMS group and the three non-sarcomatous groups was highly significant (p < 0.001). Combined high PR - low p53 expression was seen in all the 26 examined cases of the non-sarcomatous group including the STUMP cases and none of the LMS cases. Therefore, it represents a "benign" profile with 100% specificity in diagnosis of a non-sarcomatous tumor.

Conclusion

Immunohistochemistry for PR and p53 is valuable as an adjunct tool to morphological assessment of problematic uterine smooth muscle tumors.     

Sensitization of TRAIL-resistant LNCaP cells by resveratrol (3, 4', 5 tri-hydroxystilbene): molecular mechanisms and therapeutic potential

Background

We have previously shown that prostate cancer LNCaP cells are resistant to TRAIL, and downregulation of PI-3K/Akt pathway by molecular and pharmacological means sensitizes cells to undergo apoptosis by TRAIL and curcumin. The purpose of this study was to examine the molecular mechanisms by which resveratrol sensitized TRAIL-resistant LNCaP cells.

Results

Resveratrol inhibited growth and induced apoptosis in androgen-dependent LNCaP cells, but had no effect on normal human prostate epithelial cells. Resveratrol upregulated the expression of Bax, Bak, PUMA, Noxa, Bim, TRAIL-R1/DR4 and TRAIL-R2/DR5, and downregulated the expression of Bcl-2, Bcl-X_L, survivin and XIAP. Treatment of LNCaP cells with resveratrol resulted in generation of reactive oxygen species, translocation of Bax and p53 to mitochondria, subsequent drop in mitochondrial membrane potential, release of mitochondrial proteins (cytochrome c, AIF, Smac/DIABLO and Omi/HtrA2), activation of caspase-3 and caspase-9 and induction of apoptosis. The ability of resveratrol to sensitize TRAIL-resistant LNCaP cells was inhibited by dominant negative FADD, caspase-8 siRNA or N-acetyl cysteine. Smac siRNA inhibited resveratrol-induced apoptosis, whereas Smac N7 peptide induced apoptosis and enhanced the effectiveness of resveratrol.

Conclusion

Resveratrol either alone or in combination with TRAIL or Smac can be used for the prevention and/or treatment of human prostate cancer.