Thyroid status modulates T lymphoma growth via cell cycle regulatory proteins and angiogenesis

We have shown in vitro that thyroid hormones (THs) regulate the balance between proliferation and apoptosis of T lymphoma cells. The effects of THs on tumor development have been studied, but the results are still controversial. Herein, we show the modulatory action of thyroid status on the in vivo growth of T lymphoma cells. For this purpose, euthyroid, hypothyroid, and hyperthyroid mice received inoculations of EL4 cells to allow the development of solid tumors. Tumors in the hyperthyroid animals exhibited a higher growth rate, as evidenced by the early appearance of palpable solid tumors and the increased tumor volume. These results are consistent with the rate of cell division determined by staining tumor cells with carboxyfluorescein succinimidyl ester. Additionally, hyperthyroid mice exhibited reduced survival. Hypothyroid mice did not differ significantly from the euthyroid controls with respect to these parameters. Additionally, only tumors from hyperthyroid animals had increased expression levels of proliferating cell nuclear antigen and active caspase 3. Differential expression of cell cycle regulatory proteins was also observed. The levels of cyclins D1 and D3 were augmented in the tumors of the hyperthyroid animals, whereas the cell cycle inhibitors p16/INK4A (CDKN2A) and p27/Kip1 (CDKN1B) and the tumor suppressor p53 (TRP53) were increased in hypothyroid mice. Intratumoral and peritumoral vasculogenesis was increased only in hyperthyroid mice. Therefore, we propose that the thyroid status modulates the in vivo growth of EL4 T lymphoma through the regulation of cyclin, cyclin-dependent kinase inhibitor, and tumor suppressor gene expression, as well as the stimulation of angiogenesis.

WIF1 can effectively co-regulate pro-apoptotic activity through the combination with DKK1

Wnt inhibitory factor-1 (WIF1) is a conserved lipid-binding protein that interrupts Wnt ligands by interacting with their Frizzled receptors. Thus, they may suppress the activation of the Wnt/β-catenin triggered signaling cascade. Recently, we found that WIF1 can effectively co-regulate pro-apoptotic activity through the combination with Dickkopf-1 (DKK1). The tumor suppressor p53 protein expression was remarkably increased in the WIF1- and DKK1-transfected cells, along with p21. In contrast, expressions of the anti-apoptotic proteins, c-Myc and Bcl-2, were noticeably reduced. In addition, WIF1 and/or DKK1 significantly activated the transcription of p21 and p53, whereas c-Myc and Bcl-2 activities were remarkably reduced. The tumor suppressor WIF1 was also found to be capable of suppressing tumor growth through the inhibition of tumor angiogenesis in the cellular biological/physiological condition through the targeting of the PI3K/Akt/mTOR signaling pathway, while also being recognized as a Wnt antagonist factor in the Wnt cascade. Consistently, WIF1 conspicuously decreased the VEGF-induced phosphorylation of the PI3K/Akt signaling cascade components, including PDK1, mTOR, TSC-2, GSK-3β, and the p70S6K protein. Collectively, our results indicate for the first time that the tumor suppressor WIF1 is involved in angiogenesis and supplies a possible molecular target for the treatment of distinct malignant cancers, as well as several other associated diseases.

Increased expression of prothymosin-α, independently or combined with TP53, correlates with poor prognosis in colorectal cancer

Human prothymosin-α (PTMA) plays an important role in tumorigenesis, and its overexpression triggers a TP53 response. In this study, we identified that PTMA expression was up-regulated at both the transcriptional and translational level in tumor tissue compared to that in adjacent normal tissue. PTMA overexpression was significantly associated with the depth of tumor invasion, lymph node metastasis (LNM), distant metastasis, advanced AJCC stage, and tumor differentiation. There was also a significant association between PTMA over-expression and mutant TP53 expression (r=0.515, P < 0.001). Survival analysis revealed that the disease-free survival (DFS) and overall survival (OS) rates were significantly lower among patients with PTMA- and TP53-positive tumors. Hence, PTMA might play an important role in the progression of CRC, and the assessment of both PTMA and mutant TP53 expression can help predict colon cancer prognosis.

Potential dual immunomodulatory role of VEGF in ulcerative colitis and colorectal carcinoma

OBJECTIVE

Progression from ulcerative colitis (UC) toward colorectal carcinoma (CRC) is multistep process that includes gene alterations of tumor suppressor genes, such as p53 and p16. The aim of this study was to investigate the expression patterns of p16, p53 and VEGF in affected tissue and serum levels of cytokines TNF-α, IFN-γ, IL-4, IL-6, IL-10 and IL-17 in patients with UC and CRC, respectively. MATHERIALS AND METHODS. Serum levels of cytokine in patients with UC (n=24) and CRC (n=75) and in a healthy group (n=37) were analyzed by ELISA. Endoscopic biopsies specimens of UC and CRC were studied by immunohistochemical staining for p16, p53 and VEGF.

RESULTS

Patients with UC with presence of extraintestinal manifestations, complications, and positive staining of p16, p53 and VEGF respectively had higher serum levels of pro-inflammatory cytokines. Higher percentage of CRC patients had positive staining of p16, p53 and VEGF. CRC patients with positive staining of VEGF had decreased systemic values of pro-inflammatory IFN-γ and increased values of immunosuppressive IL-10.

CONCLUSIONS

Relatively low IL-10 in patients with severe UC is insufficient to compensate IL-6 secretion and subsequently enhanced type 1/17 immune response. In UC patients, p16 and p53 induce enhanced VEGF expression and subsequent production of pro-inflammatory TNF-α and IL-6. In CRC patients VEGF seems to have immunosuppressive role. It appears that tumor suppressor gene-VEGF axis have dual role on immune response in inflammation of UC and tumor growth and progression of CRC.

High incidence of female reproductive tract cancers in FA-deficient HPV16-transgenic mice correlates with E7's induction of DNA damage response, an activity mediated by E7's inactivation of pocket proteins

Fanconi anemia (FA) is a rare genetic disorder caused by defects in a DNA damage repair system, the FA pathway. FA patients frequently develop squamous cell carcinoma (SCC) at sites that are associated with human papillomavirus (HPV)-driven cancer including the female reproductive tract. To assess experimentally whether FA deficiency increases susceptibility to HPV-associated cervical/vaginal cancer, we monitored cancer incidence in the female lower reproductive tract of FA-deficient mice expressing HPV16 oncogenes, E6 and/or E7. FA deficiency specifically increased the incidence of cancers in mice expressing E7; but this effect was not observed in mice just expressing E6. We also observed that E7, but not E6, induced DNA damage as scored by induction of γ-H2AX and 53BP1 (p53 binding protein 1) nuclear foci, and this induction was heightened in FA-deficient tissue. Finally, we discovered that this induction of DNA damage responses was recapitulated in mice deficient in expression of 'pocket' proteins, pRb, p107 and p130, which are established targets of E7. Our findings support the hypothesis that E7 induces cancer by causing DNA damage at least in part through the inactivation of pocket proteins. This hypothesis explains why a deficiency in DNA damage repair would increase susceptibility to E7-driven cancer.

Possible prognostic significance of p53, cyclin D1 and Ki-67 in the second primary malignancy of patients with double primary malignancies

Patients with two types of primary cancers are rare. In this study, we investigated the expression of p53, cyclin D1, and Ki-67 in the second primary malignancy. Tissue samples were obtained from the second primary cancer site of 43 patients who met the diagnostic criteria for double primary cancer. p53, cyclin D1 and Ki-67 were determined using immunohistochemistry. Categorical variables were compared using the Chi-squared test; correlation between data scores and histology was calculated using the Spearman's rank-order correlation. The expression rates of p53, cyclin D1 and Ki-67 in the second primary malignancy site were 60.5%, 30.2% and 65.1% respectively. p53 expression showed statistically significant association with tumor occurrence interval, pathological grading and nodal metastasis (p < 0.05). Positive correlation was detected between the expression of cyclin D1 and Ki-67 and the expression of p53 (r = 0.313, p = 0.041; r = 0.319, p = 0.037, respectively). High-expressing p53 or cyclin D second primary malignancies were associated with decreased overall survival (p = 0.040 and p = 0.043, respectively). Ki-67 expression levels did not exhibit statistically significant differences in survival. In conclusion, elevated protein expression of p53, cyclin D1 and Ki-67 in the second primary malignancy is an indicator of more aggressive malignant behavior of the secondary tumor. These markers may have prognostic value in the clinical setting.

Over-expression of p53, p21 and Cdc2 in histologically negative surgical margins is correlated with local recurrence of laryngeal squamous cell carcinoma

The aim of this study was to explore the relationship between the expression of p53, p21 and Cdc2 in the early laryngeal cancer with negative pathological margins and its local recurrence. During 2004-2010, a total of 85 patients with early laryngeal cancer were selected in Tangshan Union Hospital, Hebei, China, and immunohistochemical method was used to detect the expression of p53, p21 and Cdc2 in the negative pathological margin tissues. All patients were followed up for two years to collect pathological data for evaluating the survival and tumor recurrence. Two years after surgery 14 of 85 patients with laryngeal cancer presented with recurrence (recurrent group), while 71 patients without recurrence (none recurrent group). The positive rate of p53, p21 and Cdc2 protein in laryngeal cancer tissues was 60.0% (51/85), 38.8% (33/85) and 70.6% (60/85), respectively, while that of the three proteins in the cancer adjacent tissues was 36.5% (31/85), 21.2% (18/85) and 29.4% (25/85), respectively. The differentiation and TNM stage of tumor had no correlation with the three proteins. The positive rate of p53 in the surgical margin of the recurrent group and non recurrent group was 71.4% (10/14) and 29.6% (21/71) (P = 0.003), that of p21 was 50.0% (7/14) and 15.5% (11/71), (P = 0.011) and Cdc2 was 57.1% (8/14) and 23.9% (17/71) (P = 0.030), respectively. In conclusion, p53, p21 and Cdc2 may be involved in the occurrence, development and recurrence of laryngeal squamous cell carcinoma. Overexpression of p53, p21 and Cdc2 in the surgical margin of early laryngeal cancer is closely related to local recurrence of tumor.

Signalling pathways involved in antitumoral effects of VIP in human renal cell carcinoma A498 cells: VIP induction of p53 expression

Vasoactive intestinal peptide (VIP) decreases cell proliferation through PI3K signalling and prevents tumour progression in clear renal cell carcinoma (RCC). Here we analyzed the signalling pathways that mediate such VIP effects by using human RCC A498 cells. The effects of treatment with 1 μM VIP and/or specific protein kinase inhibitors such as H89, Wortmannin and PD98059 were studied by cell adhesion assay, ELISA of VEGF165 and ROS production assays. Semiquantitative RT-PCR and western blot were performed to study p53 expression. VIP increased cell adhesion and ROS production, and decreased VEGF165 secretion through PI3K signalling. Moreover, VIP increased nuclear expression of tumour suppressor p53. VIP effects could be blocked by cell incubation with a specific p53 inhibitor, cyclin pifithrin-α hydrobromide (CPFT-αH). In conclusion, this study provides a p53-dependent mechanism by which VIP regulates cell proliferation in RCC development. It supports a potential usefulness of VIP in new therapies of RCC.

Predictors of recurrence in breast cancer subtypes with negative lymph node in a Chinese population

To establish a series of objective parameters to predict the risk of relapse from axillary lymph node-negative (ANN) breast cancer, and evaluate the patterns of recurrence according to molecular subtypes, we collected information on 2126 consecutive breast cancer patients operated between 2002 and 2006. In this case-control study, 212 patients experiencing recurrence or breast cancer related death were defined as 'poor group'. Another 212 patients were selected from the remaining cases with stratified sampling method to comprise the 'good group'. Significant differences were found in vascular invasion, grade and molecular subtype between the two groups. Expression of ER and PR in the 'poor group' was lower (P < 0.05). However, positive rates of Ki67, p53 and VEGF in the 'poor group' were higher (P < 0.05). Multivariate analysis revealed that molecular subtype, expression of VEGF, tumor grade, and vascular invasion were closely correlated with bad outcome. Analysis of the 'poor group' demonstrated that 'HER2 positive' and 'triple negative' subtypes more commonly suffered from distant metastases and death. No metastasis was found in patients with pure invasive papillary carcinoma, invasive cribriform carcinoma or adenoid cystic carcinoma, whereas the diagnoses of invasive micropapillary carcinoma, invasive apocrine carcinoma, invasive papillary carcinoma mixed with invasive ductal carcinoma, or metaplastic carcinoma were correlated with distant metastasis and death. In conclusion, molecular subtype and expression of VEGF are useful markers for predicting prognosis of ANN breast cancer patients. 'Luminal A-like' subtype has better outcome than others. Moreover, molecular subtypes have different recurrence patterns.

Glucose deprivation induces G2/M transition-arrest and cell death in N-GlcNAc2-modified protein-producing renal carcinoma cells

Some cancer cells can survive under glucose deprivation within the microenvironment of a tumor. Recently, we reported that N-linked (β-N-acetylglucosamine)2 [N-GlcNAc2]-modified proteins induce G2/M arrest and cell death under glucose deprivation. Here, we investigated whether such a response to glucose deprivation contributes to the survival of renal cell carcinomas, which are sensitive to nutritional stress. Specifically, we analyzed seven renal carcinoma cell lines. Four of these cell lines produced N-GlcNAc2-modified proteins and led G2/M-phase arrest under glucose deprivation, leading to cell death. The remaining three cell lines did not produce N-GlcNAc2-modified proteins and undergo G1/S-phase arrest under glucose deprivation, leading to survival. The four dead cell lines displayed significant up-regulation in the UDP-GlcNAc biosynthesis pathway as well as increased phosphorylation of p53, which was not observed in the surviving three cell lines. In addition, the four dead cell lines showed prolonged up-regulated expression of ATF3, which is related to unfolded protein response (UPR), while the surviving three cell lines showed only transient up-regulation of ATF3. In this study, we demonstrated that the renal carcinoma cells which accumulate N-GlcNAc2-modified proteins under glucose deprivation do not survive with abnormaly prolonged UPR pathway. By contrast, renal carcinoma cells that do not accumulate N-GlcNAc2-modified proteins under these conditions survive. Morover, we demonstrated that buformin, a UPR inhibitor, efficiently reduced cell survival under conditions of glucose deprivation for both sensitive and resistant phenotypes. Further studies to clarify these findings will lead to the development of novel chemotherapeutic treatments for renal cancer.

Pathway-driven discovery of rare mutational impact on cancer

Identifying driver mutation is important in understanding disease mechanism and future application of custom tailored therapeutic decision. Functional analysis of mutational impact usually focuses on the gene expression level of the mutated gene itself. However, complex regulatory network may cause differential gene expression among functional neighbors of the mutated gene. We suggest a new approach for discovering rare mutations that have real impact in the context of pathway; the philosophy of our method is iteratively combining rare mutations until no more mutations can be added under the condition that the combined mutational event can statistically discriminate pathway level mRNA expression between groups with and without mutational events. Breast cancer patients with somatic mutation and mRNA expression were analyzed by our approach. Our approach is shown to sensitively capture mutations that change pathway level mRNA expression, concurrently discovering important mutations previously reported in breast cancer such as TP53, PIK3CA, and RB1. In addition, out of 15,819 genes considered in breast cancer, our approach identified mutational events of 32 genes showing pathway level mRNA expression differences.

Artemisinin inhibits gastric cancer cell proliferation through upregulation of p53

Recent population studies suggest that the use of artemisinin is associated with reduced incidence and improved prognosis of certain cancers. In the current study, we assessed the effect of artemisinin on gastric cancer cells (AGS and MKN74 cells). We found that artemisinin inhibited growth and modulated expression of cell-cycle regulators in these cells. Treatment with artemisinin was also associated with induction of p27 kip1 and p21 kip1, two negative cell-cycle regulators. Furthermore, we revealed that artemisinin treatment led to an increased expression of p53. Taken together, these results provide evidence for a mechanism that may contribute to the antineoplastic effects of artemisinin suggested by recent population studies and justify further work to explore potential roles for it in gastric cancer prevention and treatment.

Swietenia macrophylla King induces mitochondrial-mediated apoptosis through p53 upregulation in HCT116 colorectal carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Swietenia macrophylla King is a traditional herb used to treat various diseases including hypertension, diabetes and cancer. Previous study demonstrated its anti-tumor effect but the potential mechanisms have not been clearly defined. The current study was to further investigate the underlying mechanism of ethyl acetate fraction of Swietenia macrophylla (SMEAF)-induced anti-proliferative effect and apoptosis in HCT116 colorectal carcinoma cell.

MATERIALS AND METHODS

Cell viability was evaluated in HCT116 cells by trypan blue exclusion assay. Apoptotic cell death was detected by Hoechst 33342/propidium iodide (PI) staining and intracellular reactive oxygen species (ROS) was analyzed by flow cytometry. The apoptotic gene and protein expression were determined by Real-time quantitative PCR (q-PCR) and immunofluorescence staining using flow cytometry, respectively.

RESULTS

SMEAF significantly inhibited HCT116 cell viability and induced apoptosis in a dose-dependent manner. SMEAF-induced apoptosis was triggered by the activation of p53 and intracellular reactive oxygen species (ROS) production. Moreover, the significant increase in p53 was accompanied by a decrease murine double minute 2 (MDM2) expression. SMEAF significantly increased the expression of the Bax protein resulting in a markedly elevated Bax/Bcl-2 ratio which may have triggered the mitochondrial apoptotic pathway, resulting in caspase-3/7 and caspase-9 activation.

CONCLUSION

These results suggested that SMEAF exerts its antitumor activity in HCT116 cells by activating proapoptotic signaling pathway through intracellular ROS formation triggering the mitochondrial-mediated pathway via p53 activation.

Transcriptional regulators TRIM28, SETDB1, and TP53 are aberrantly expressed in porcine embryos produced by in vitro fertilization in comparison to in vivo- and somatic-cell nuclear transfer-derived embryos

In vitro embryo production is important for research in animal reproduction, embryo transfer, transgenics, and cloning. Yet, in vitro-fertilized (IVF) embryos are generally developmentally delayed and are inferior to in vivo-derived (IVV) embryos; this discrepancy is likely a result of aberrant gene expression. Transcription of three genes implicated to be important in normal preimplantation embryo development, TRIM28, SETDB1, and TP53, was determined by quanitative PCR in IVF, somatic-cell nuclear transfer (SCNT), parthenogenetic, and IVV porcine oocytes and embryos. There was no difference in TRIM28 or SETDB1 abundance between oocytes matured in vitro versus in vivo (P > 0.05), whereas TP53 levels were higher in in vitro-matured oocytes. TRIM28 increased from metaphase-II oocytes to the 4-cell and blastocyst stages in IVF embryos, whereas IVV embryos showed a reduction in TRIM28 abundance from maturation throughout development. The relative abundance of TP53 increased by the blastocyst stage in all treatment groups, but was higher in IVF embryos compared to IVV and SCNT embryos. In contrast, SETDB1 transcript levels decreased from the 2-cell to blastocyst stage in all treatments. For each gene analyzed, SCNT embryos of both hard-to-clone and easy-to-clone cell lines were more comparable to IVV than IVF embryos. Knockdown of TRIM28 also had no effect on blastocyst development or expression of SETDB1 or TP53. Thus, TRIM28, SETDB1, and TP53 are dynamically expressed in porcine oocytes and embryos. Furthermore, TRIM28 and TP53 abundances in IVV and SCNT embryos are similar, but different from quantities in IVF embryos. Mol. Reprod. Dev. 81: 552–556, 2014. © 2014 The Authors. Published by Wiley Periodicals, Inc.

MiR-135a functions as a tumor suppressor in epithelial ovarian cancer and regulates HOXA10 expression

The activation of homeobox A10 (HOXA10) has been proved to be an important event in epithelial ovarian carcinogenesis, yet its regulation in epithelial ovarian cancer (EOC) is still not fully understood. Here, we aimed to reveal the mechanism that a predicted target miRNA regulates HOXA10 expression and the association of its expression with progression of EOC. Here, by using computer-assisted algorithms from PicTar, TargetScan, and miRBase, we identified that the predicted target miRNA of HOXA10 was miR-135a. MiR-135a expression in EOC tissues and controls was measured with quantitative RT-PCR. The role of miR-135a and HOXA10 in the growth and survival of several EOC cell lines was determined with several in vitro approaches. We found that miR-135a expression was downregulated in an EOC patient cohort. Also, patients with low miR-135a expression had shorter overall survival and progression-free survival durations than those with high expression. Functional analysis of three EOC-derived cell lines (SKOV-3, HEY, and OVCAR-3) demonstrated that miR-135a directly regulated HOXA10 expression by targeting its 3'-UTR. Inhibition of HOXA10 expression with miR-135a mimics and HOXA10 siRNA consistently resulted in cell apoptosis with concomitant enhancement of caspase-3, increase of p53 expression and reduction of Bcl-2 expression, and also suppressed cell growth and adhesion. These findings suggest that ubiquitous loss of miR-135a expression is a critical mechanism for the overexpression of HOXA10 in EOC cells, which is implicated in epithelial ovarian carcinogenesis. Furthermore, miR-135a may be predictive of EOC prognosis.

Correlation of Nrf2, NQO1, MRP1, cmyc and p53 in colorectal cancer and their relationships to clinicopathologic features and survival

Due to emergence of resistant tumor populations, prognosis for metastatic colorectal cancer (CRC) patients remains poor and five-year survival rate is still very low. To guide clinicians in selecting treatment option for CRC patients, reliable markers predictive of poor clinical outcome are desirable. This study analyzed the correlation of NF-E2-related factor 2 (Nrf2), NAD(P)H quinine oxidoreductase 1 (NQO1), multidrug resistant protein 1 (MRP1), cmyc and p53 in CRC and their relationships to Duke's stage and clinical prognosis. 76 specimens of CRC tissues were immunohistochemically investigated using Nrf2, NQO1, MRP1, cmyc and p53 antibodies. IHC stain showed that Nrf2, NQO1, MRP1, cmyc and p53 were highly expressed in CRC tissues compared with adjacent non-tumor tissues. Significant positive correlations were found between the expression of Nrf2 and that of NQO1, MRP1, cmyc and p53. Moreover, there was significant correlation between the high level of Nrf2, NQO1, MRP1, p53 expression and Duke's stage, as well as poor clinical prognosis. We confirmed that Nrf2, NQO1, MRP1, and p53 expression exhibits considerable heterogeneity according to CRC clinical stage and prognosis. Nrf2 is the most promising biomarker in identifying a poor prognostic group of CRC.

The role of activation-induced cytidine deaminase expression in gastric adenocarcinoma

BACKGROUND

Gastric adenocarcinoma is one of the most common malignant tumors and the leading cause of malignancy-related death worldwide. Studies have reported overexpression of activation-induced cytidine deaminase (AID) and protein kinase c iota (PKCi) proteins showing involvement in the regulation of carcinogenesis. In the present study, we investigated the expression of AID and PKCi in patients with gastric adenocarcinoma and determined the correlation between these proteins.

MATERIALS AND METHODS

This study was conducted between September 2009 and September 2010 on a total of 59 patients with gastric adenocarcinoma at the Tokushima University Hospital. AID, PKCi and mutated p53 protein expressions were evaluated by immunohistochemistry in gastric adenocarcinoma.

RESULTS

High AID and PKCi expression was significantly (p<0.05) associated with poorly-differentiated gastric adenocarcinoma. In addition, PKCi expression was significantly correlated with clinicopathological findings such as a lymph node metastasis, and venous and lymphatic invasion (p<0.05). Furthermore, AID expression was significantly correlated with PKCi and mutated p53 protein expression in gastric adenocarcinoma (p<0.05).

CONCLUSION

High AID and PKCi expressions were significantly correlated with poorly-differentiated gastric adenocarcinoma.

The expression of EGFR, cerbB2, p16, and p53 and their relationship with conventional parameters in squamous cell carcinoma of the larynx

BACKGROUND/AIM

To investigate the expression of epidermal growth factor receptor-HER1 (EGFR), cerbB2 (HER2), p16, and p53, as well as the relationship of the expression of these genes with conventional parameters in squamous cell carcinoma (SCC) of the larynx.

MATERIALS AND METHODS

Samples from 92 cases of diagnosed laryngeal SCC between 2001 and 2011 from the Pathology Department of Ministry of Health Ankara D1şkapi Yildirinm Beyazit Teaching & Research Hospital were studied by immunohistochemistry using EGFR, cerbB2, p16, and p53 antibodies.

RESULTS

An increase in the TNM stage and pathological tumor size status correlated with an increase in EGFR and cerbB2 expression. In the cases with lymphovascular invasion, the expression was detected at a higher ratio. Cases in which high levels ofpl6 and p53 expression were observed did not show any lymphovascular invasions.

CONCLUSION

Expressions of p53 and p16 were considered to be most effective in early carcinogenesis stages of laryngeal SCC. In comparison with p53 and p16 expression levels, EGFR and cerbB2 expression levels were observed to be associated with poor prognostic parameters and were higher at later stages of laryngeal carcinogenesis development.

The effect of nitidine chloride on the proliferation and apoptosis of nasopharyngeal carcinoma cells

PURPOSE

This study was conducted to investigate the effect of nitidine chloride (NC) on the proliferation and apoptosis of nasopharyngeal carcinoma cell line CNE1, CNE2, TWO3, and C666-1, and to explore its antitumor mechanism.

METHODS

NC was dissolved in IMDM medium and cultured with nasopharyngeal carcinoma cell line CNE1, CNE2, TWO3 and C666-1. Cell morphology, cell proliferation, cell apoptosis, p53 mRNA and p53 protein levels were assessed.

RESULTS

After incubation with NC for 24 h, typical apoptotic morphology was observed. NC inhibited the proliferation and induced apoptosis of all 4 cell lines in a time-dose dependent manner. p53 mRNA and p53 protein levels were significantly increased.

CONCLUSIONS

NC inhibited proliferation and induced apoptosis of nasopharyngeal carcinoma cells with upregulation of p53 gene.

D-pinitol promotes apoptosis in MCF-7 cells via induction of p53 and Bax and inhibition of Bcl-2 and NF-κB

Development of drugs from natural products has been undergoing a gradual evoluation. Many plant derived compounds have excellent therapeutic potential against various human ailments. They are important sources especially for anticancer agents. A number of promising new agents are in clinical development based on their selective molecular targets in the field of oncology. D-pinitol is a naturally occurring compound derived from soy which has significant pharmacological activitites. Therefore we selected D-pinitol in order to evaluate apoptotic potential in the MCF-7 cell line. Human breast cancer cells were treated with different concentrations of D-pinitol and cytotoxicity was measured by MTT and LDH assays. The mechanism of apoptosis was studied with reference to expression of p53, Bcl-2, Bax and NF-kB proteins. The results revealed that D-pinitol significantly inhibited the proliferation of MCF-7 cells in a concentration-dependent manner, while upregulating the expression of p53, Bax and down regulating Bcl-2 and NF-kB. Thus the results obtained in this study clearly vindicated that D-pinitol induces apotosis in MCF-7 cells through regulation of proteins of pro- and anti-apoptotic cascades.

Differential responses of neuronal and spermatogenic cells to the doppel cytotoxicity

Although structurally and biochemically similar to the cellular prion (PrP(C)), doppel (Dpl) is unique in its biological functions. There are no reports about any neurodegenerative diseases induced by Dpl. However the artificial expression of Dpl in the PrP-deficient mouse brain causes ataxia with Purkinje cell death. Abundant Dpl proteins have been found in testis and depletion of the Dpl gene (Prnd) causes male infertility. Therefore, we hypothesize different regulations of Prnd in the nerve and male productive systems. In this study, by electrophoretic mobility shift assays we have determined that two different sets of transcription factors are involved in regulation of the Prnd promoter in mouse neuronal N2a and GC-1 spermatogenic (spg) cells, i.e., upstream stimulatory factors (USF) in both cells, Brn-3 and Sp1 in GC-1 spg cells, and Sp3 in N2a cells, leading to the expression of Dpl in GC-1 spg but not in N2a cells. We have further defined that, in N2a cells, Dpl induces oxidative stress and apoptosis, which stimulate ataxia-telangiectasia mutated (ATM)-modulating bindings of transcription factors, p53 and p21, to Prnp promoter, resulting the PrP(C) elevation for counteraction of the Dpl cytotoxicity; in contrast, in GC-1 spg cells, phosphorylation of p21 and N-terminal truncated PrP may play roles in the control of Dpl-induced apoptosis, which may benefit the physiological function of Dpl in the male reproduction system.

Location of proliferating cell nuclear antigen and p53 protein in human first trimester and term placenta

OBJECTIVE

To examine immunohistochemically the distribution of cell-cycle regulators p53 and proliferating cell nuclear antigen (PCNA), which are in close cooperation with each other in first trimester and term human placentas.

STUDY DESIGN

Human first trimester placental tissue was obtained by curettage from legal abortions obtained for social reasons, and human term placental tissue was obtained. Neither the interrupted pregnancy nor the obstetrical history showed any abnormalities. A total of 12 tissue samples were analyzed: n = 6 (6-12 weeks), n = 6 (38-40 weeks). Tissues were evaluated by immunohistochemical study.

RESULTS

In the first trimester p53 expression was at a normal level, and p53 immunolabeling was present in syncytiotrophoblast and extravillous trophoblast cells found in the cell column. Very few villous stroma cells were p53 positive. PCNA was present intensely in the cytotrophoblast and in extravillous trophoblast found in the cell column. In term placentas p53 immunolabeling was very low and was expressed in only a limited number of syncytiotrophoblast cells. PCNA was at a normal level in villous and extravillous tissue. PCNA was decreased when compared with the first trimester and was present in syncytiotrophoblast and cytotrophoblast cells. A small number of endothelial cells and villous stromal cells were positive.

CONCLUSION

We think that the immunohistochemical distribution of PCNA and p53 are strongly coordinated with each other in villous and extravillous cells in human placenta. This finding may be useful in the explanation of placental pathologies.

Study of the biologic behavior of odontogenic keratocyst and orthokeratinaized odontogenic cyst using TGF-alpha and P53 markers

Odontogenic keratocyst (OKC) is an aggressive cyst, and its recurrence rate is higher than that of other odontogenic cysts. Orthokeratinized odontogenic cyst (OOC) is less aggressive than OKC, but bears the probability of carcinomatous changes. In this study, we evaluated the expression and intensity of P53 and TGF-alpha in order to compare the biologic behavior or probable carcinomatous changes of these two cysts. In this cross-sectional study, 15 OKC and 15 OOC were stained immunohistochemically for P53 and TGF-alpha using the Novolink polymer method. Then, all slides were examined by an optical microscope with 400× magnification, and the stained cells in the basal and parabasal layers were counted. Finally, the results were analyzed by the Mann-Whitney and Wilcoxon tests (P-value<0.05). The difference between the expression of P53 and TGF alpha in the basal layer of OKC and OOC was not statistically significant (P-value>0.05), but the expression of P53 and TGF-alpha in the parabasal layer in OKC was statistically higher compared to OOC (P<0.05). Considering the known role of P53 and TGF-alpha in malignant changes and the higher expression of P53 and TGF-alpha in OKC compared to those in OOC, the probability of carcinomatous changes was higher in OKC than in OOC.

Melatonin promotes the in vitro development of pronuclear embryos and increases the efficiency of blastocyst implantation in murine

When a defect occurs in the in vitro development of a pronuclear embryo, the interruption of the subsequent implantation limits the success of assisted conception. This common problem remains to be solved. In this study, we observed that melatonin at its physiological concentration (10(-7)  m) significantly promoted the in vitro development of murine pronuclear embryos. This was indicated by the increased blastocyst rate, hatching blastocyst rate, and blastocyst cell number with melatonin treatment. In addition, when these blastocysts were implanted into female recipient mice, the pregnancy rates (95.0% versus control 67.8%), litter sizes (4.1 pups/litter versus control 2.7 pups/litter), and postnatal survival rates of offspring (96.84% versus control 81.24%) were significantly improved compared with their non-melatonin-treated counterparts. Mechanistic studies revealed that melatonin treatment upregulates gene expression of the antioxidant enzyme, superoxide dismutase (SOD), and the anti-apoptotic factor bcl-2 while downregulating the expression of pro-apoptotic genes p53 and caspase-3. Due to these changes, melatonin treatment reduces ROS production and cellular apoptosis during in vitro embryo development and improves the quality of blastocysts. The implantation of blastocysts with higher quality leads to more healthy offspring and increased pup survival.