ASPP and iASPP: Implication in cancer development and progression.

The well-known guardian of genome, p53 plays critical roles in the induction of apoptosis typically upon DNA damage whereas mutant p53 containing cells are unable to undergo apoptosis which leads to aggressive tumor growth and drug resistance. Moreover, another molecule regulating wild-ype p53 function is ASPP (apoptosis stimulating proteins of p53) family. ASPP family consists of ASPP1 and ASPP2, and functions as tumor suppressors whereas the inhibitor of ASPP (iASPP) functions as oncogene. By binding to apoptosis regulating proteins such as p53, p63, p73, Bcl-2, NF-κB p65, etc., ASPP1 and ASPP2 promote apoptosis while overexpression of iASPP inhibits apoptotic cell death typically after DNA damage. In cancer cells, the aberrant expressions of ASPP1, ASPP2 and iASPP have been observed, especially, the high expression of iASPP in cancers is associated with worse disease status, therapy resistance and poor survival of patients with cancers. The molecular interactions between the members of ASPP family and their binding proteins in apoptotic pathway together with other regulators such as miR-124, NF-κB regulated Twist, snail, etc. form a complex signal transduction network to control apoptosis and tumor growth. Therefore, targeting ASPP family could regulate the aberrant communications in the signal transduction network to induce apoptosis and drug sensitivity. Several peptides, miRNAs and natural agents have been used to target ASPP family and show encouraging results in the induction of apoptosis of cancer cells; however, more in vivo animal studies and clinical trials are needed to confirm the true value of targeting ASPP family in the treatment of cancers.

MicroRNAs in personalized cancer therapy.

MicroRNAs (miRNAs) are small endogenous noncoding single-stranded RNAs. They critically regulate the post-transcriptional activity of several key physiological and pathological cell processes including cancer. Through their transcriptional regulatory functions, miRNAs control tumor proliferation, invasion and metastasis. The expression of miRNAs is altered in malignancies. It could be either upregulated or downregulated depending upon the role of a particular miRNA in the pathogenetic development of the tumor. The upregulated miRNAs exert an 'oncogenic' effect leading to tumor proliferation and metastasis. The downregulated miRNAs have 'tumor suppressor' effects. Recent studies have demonstrated that miRNAs have a role in the early diagnosis, prognosis and treatment outcome assessment of cancers. Every tumor has specific miRNA alterations, i.e. some are overexpressed and others are downregulated. These altered miRNAs can be used as a tumor-specific 'signature' for potential clinical use in improving the accuracy of diagnosis, determining prognosis and as therapeutic targets for therapy. Specific miRNAs can be targeted using oligonucleotide sequences corresponding to the altered miRNAs. These are referred to as 'antagomirs'. Depending upon the miRNA alterations in the tumor of an individual patient, one could design targeted therapies for personalized medicine in patients. Hence, miRNAs have an immense role in personalized cancer therapy.

Redox cycling of endogenous copper by thymoquinone leads to ROS-mediated DNA breakage and consequent cell death: putative anticancer mechanism of antioxidants.

Plant-derived dietary antioxidants have attracted considerable interest in recent past for their chemopreventive and cancer therapeutic abilities in animal models. Thymoquinone (TQ) is the major bioactive constituent of volatile oil of Nigella sativa and has been shown to exert various pharmacological properties, such as anti-inflammatory, cardiovascular, analgesic, anti-neoplastic, anticancer and chemopreventive. Although several mechanisms have been suggested for the chemopreventive and anticancer activity of TQ, a clear mechanism of action of TQ has not been elucidated. TQ is a known antioxidant at lower concentrations and most of the studies elucidating the mechanism have centered on the antioxidant property. However, recent publications have shown that TQ may act as a prooxidant at higher concentrations. It is well known that plant-derived antioxidants can switch to prooxidants even at low concentrations in the presence of transition metal ions such as copper. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Copper is an important metal ion present in the chromatin and is closely associated with DNA bases, particularly guanine. Using human peripheral lymphocytes and comet assay, we first show that TQ is able to cause oxidative cellular DNA breakage. Such a DNA breakage can be inhibited by copper-chelating agents, neocuproine and bathocuproine, and scavengers of reactive oxygen species. Further, it is seen that TQ targets cellular copper in prostate cancer cell lines leading to a prooxidant cell death. We believe that such a prooxidant cytotoxic mechanism better explains the anticancer activity of plant-derived antioxidants.

MicroRNA profiling of diagnostic needle aspirates from patients with pancreatic cancer.

BACKGROUND: A major challenge to the development of biomarkers for pancreatic cancer (PC) is the small amount of tissue obtained at the time of diagnosis. Single-gene analyses may not reliably predict biology of PC because of its complex molecular makeup. MicroRNA (miRNA) profiling may provide a more informative molecular interrogation of tumours. The primary objective of this study was to determine the feasibility of performing miRNA arrays and quantitative real-time PCR (qRT-PCR) from archival formalin-fixed paraffin-embedded (FFPE) cell blocks obtained from fine-needle aspirates (FNAs) that is the commonest diagnostic procedure for suspected PC. METHODS: MicroRNA expression profiling was performed on FFPE from FNA of suspicious pancreatic masses. Subjects included those who had a pathological diagnosis of pancreatic adenocarcinoma and others with a non-malignant pancreatic histology. Exiqon assay was used to quantify miRNA levels and qRT-PCR was used to validate abnormal expression of selected miRNAs. RESULTS: A total of 29 and 15 subjects had pancreatic adenocarcinoma and no evidence of cancer, respectively. The RNA yields per patient varied from 25 to 100 ng. Profiling demonstrated deregulation of over 228 miRNAs in pancreatic adenocarcinoma of which the top 7 were further validated by qRT-PCR. The expression of let-7c, let-7f, and miR-200c were significantly reduced in most patients whereas the expression of miR-486-5p and miR-451 were significantly elevated in all pancreas cancer patients. MicroRNAs let-7d and miR-423-5p was either downregulated or upregulated with a significant inter-individual variation in their expression. CONCLUSION: This study demonstrated the feasibility of using archival FFPE cell blocks from FNAs to establish RNA-based molecular signatures unique to pancreatic adenocarcinoma with potential applications in clinical trials for risk stratification, patient selection, and target validation.

Coinage metal complexes against breast cancer.

Breast cancer is still the leading cause of cancer deaths among women worldwide, and new therapies to treat this dangerous disease are desperately needed. The serendipitously found anticancer drug cisplatin and its second-generation congener carboplatin appear to be promising drug systems for the treatment of breast tumors, in particular of multidrug resistant and highly aggressive triple-negative subtypes. In the wake of these platinum drugs, complexes of the coinage metals copper, silver, and gold were developed that showed enhanced selectivity for breast cancer while causing fewer and weaker side-effects. This review takes stock of the latest developments in the field of coinage metal anticancer drugs with an emphasis on their biological and mechanistic aspects. Pertinent literature is covered up to 2012.

Perspectives on medicinal properties of mangiferin.

Mango tree, Mangifera indica, has been cultivated in India and several other tropical countries for centuries, and it is a good source of compound 'mangiferin'. Mangiferin's xanthonoid structure with C-glucosyl linkage and polyhydroxy component is believed to be crucial for its free radical-scavenging ability leading to a potent antioxidant effect. A number of biological activities of mangiferin have been suggested, including antidiabetic and antiinflammatory abilities. These might be explained by its antioxidant ability as well as its ability to modulate several key inflammatory pathways. Mangiferin has also been shown to be an effective inhibitor of NF-κB signaling pathway. This partially explains its antiinflammatory ability and, additionally, points towards its anticancer potential. The anticancer effects of this compound are just beginning to emerge, and in this comprehensive review, we provide information on what we know about the chemistry and biological effects of mangiferin, which would likely create interest among researchers to design further mechanistic studies in order to better understand and exploit the biological activities of this compound.

Expression of microRNAs: potential molecular link between obesity, diabetes and cancer.

Clinicians are routinely challenged in their management of cancer patients because of the complexities of obesity and diabetes that are often found as comorbid conditions. Although attention has been given to optimizing treatment planning for these patients, less attention has been given to manage their obesity and diabetes. This suggests that newer, comprehensive approaches must be developed for the treatment of cancer patients as a 'whole' rather than as a single disease. While the specific pathologies of each are unique, years of research have indicated intimate molecular links between these chronic diseases. The contribution of sedentary lifestyles and poor dietary habits is recognized; however, the precise molecular links are still not well-explored. In addition, emerging evidence suggests the important role of microRNAs (miRNAs) in the development and progression of several diseases, yet their roles in linking obesity, diabetes and cancer are only now beginning to be recognized. It is hoped that miRNAs will serve as novel biomarkers and molecular targets for cancer therapy in patients with comorbid conditions. In this review, we discuss the current understanding of the pathobiology of obesity, diabetes and cancer, and document molecular roles of miRNAs linking cancer with obesity and diabetes.

MI-219-zinc combination: a new paradigm in MDM2 inhibitor-based therapy.

Zinc has a crucial role in the biology of p53 in that p53 binds to DNA through a structurally complex domain stabilized by zinc atom. The p53 negative regulator MDM2 protein also carries a C-terminal RING domain that coordinates two zinc atoms, which are responsible for p53 nuclear export and proteasomal degradation. In this clinically translatable study, we explored the critical role of zinc on p53 reactivation by MDM2 inhibitor, MI-219, in colon and breast cancer cells. ZnCl(2) enhanced MI-219 activity (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), apoptosis and colony formation), and chelation of zinc not only blocked the activity of MI-219, but also suppressed reactivation of the p53 and its downstream effector molecules p21(WAF1) and Bax. N,N,N'N'-tetrakis(-)[2-pyridylmethyl]-ethylenediamine (TPEN), a specific zinc chelator, but not 1,2-bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (Bapta-AM), a calcium chelator, blocked MI-219-induced apoptosis. Nuclear localization is a prerequisite for proper functioning of p53 and our results confirm that TPEN, and not Bapta-AM, could abrogate p53 nuclear localization and it interfered with p53 transcriptional activation. Addition of zinc suppressed the known p53 feedback MDM2 activation, which could be restored by TPEN. Co-immunoprecipitation studies verified that MI-219-mediated MDM2-p53 disruption could be suppressed by TPEN and restored by zinc. As such, single-agent therapies that target MDM2 inhibition, without supplemental zinc, may not be optimal in certain patients owing to the less recognized mild zinc deficiency among the 'at-risk population' as in the elderly who are more prone to cancers. Therefore, use of supplemental zinc with MI-219 will benefit the overall efficacy of MIs and this potent combination warrants further investigation.

Pancreatic cancer stem cells and EMT in drug resistance and metastasis.

Pancreatic cancer (PC) is an aggressive malignancy with one of the worst outcomes among all cancers. It is the fourth leading cause of cancer death in the United States with a very low five-year survival rate. The high mortality of PC could, in part, be due to their drug resistance characteristics and high propensity for metastasis. Recently, cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT)-type cells, which shares molecular characteristics with CSCs, have been believed to play critical roles in drug resistance and cancer metastasis as demonstrated in several human malignancies including PC. Thus, the discovery of molecular knowledge of drug resistance and metastasis in relation to CSCs and EMT in PC is becoming an important area of research, and such knowledge is likely to be helpful in the discovery of newer drugs as well as designing novel therapeutic strategies for the treatment of PC with better outcome. In this brief review, we will summarize the current knowledge regarding the CSCs and EMT in the context of drug resistance and metastasis in PC, the molecular events occurring in CSCs and EMT, and the design of novel therapeutic strategies targeting CSCs and EMT-type cells to increase drug sensitivity and suppression of metastasis toward better treatment outcome of patients diagnosed with PC.

Histological complexities of pancreatic lesions from transgenic mouse models are consistent with biological and morphological heterogeneity of human pancreatic cancer.

Although pancreatic cancer is the fourth leading cause of cancer death, it has received much less attention compared to other malignancies. There are several transgenic animal models available for studies of pancreatic carcinogenesis, but most of them do not recapitulate, histologically, human pancreatic cancer. Here we review some detailed molecular complexity of human pancreatic cancer and their reflection in histomorphological complexities of pancreatic lesions developed in various transgenic mouse models with a special concern for studying the effects of chemotherapeutic and chemopreventive agents. These studies usually require a large number of animals that are at the same age and gender and should be either homozygote or heterozygote but not a mixture of both. Only single-transgene models can meet these special requirements, but many currently available models require a mouse to simultaneously bear several transgene alleles. Thus it is imperative to identify new gene promoters or enhancers that are specific for the ductal cells of the pancreas and are highly active in vivo so as to establish new single-transgene models that yield pancreatic ductal adenocarcinomas for chemotherapeutic and chemopreventive studies.

Reduction of QM protein expression correlates with tumor grade in prostatic adenocarcinoma.

The QM protein is a transcription cofactor inhibiting the activity of AP-1 transcription factors and is also a ribosomal protein participating in protein synthesis. While protein synthesis is known to be increased in many cancers, inhibition of AP-1 activity presumably suppresses development and growth of sex-hormone-regulated tumor cells. The present study is the first report on immunohistochemical data of QM in human prostatic tissues. Paraffin sections of human prostate cancer samples were immunohistochemically stained for QM. The staining scores were analyzed with the clinicopathologic data of the patients. QM protein expression was found in all normal prostate glands adjacent to prostate cancer and in various intraepithelial neoplasia (PIN). In prostate cancer, the staining intensity and stained areas were decreased, compared to the normal glands and PIN lesions; in high-grade tumors only some patches of tumor cells showed positivity. Intense (3+) staining was mostly observed in the Gleason grade three areas (48%) compared to grade 4 and 5 areas (22%), although both low and high-grade tumors showed similar percentages of weakly stained areas. Moreover, staining in prostatic adenocarcinoma was often topographically patchy and varied from negative or weak (1+) to intense (3+). There was an inverse correlation from normal to low-grade tumors and then to high-grade tumors. However, in high-grade tumors, the positive areas were mostly confined to peripheral aspects of tumors and were particularly strong in foci of perineural invasion. This preliminary study suggests that decreased QM expression may be associated with early development of prostate cancer, but later a high level of QM may facilitate progression of the tumors to a more aggressive phenotype.

The effect of genistein supplementation on performance and antioxidant status of Japanese quail under heat stress.

Genistein, a phytoestrogen found in soybeans, is a powerful antioxidant. We evaluated the effects of genistein supplementation on performance, carcass characteristics, levels of malondialdehyde (MDA), homocysteine, vitamins C, E, A in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34 degrees C. Two hundred and forty Japanese quails (10 d old) were randomly assigned to eight treatment groups consisting of 10 replicates of three birds. The birds were kept in an environmental controlled room either for 24 h/d at 22 degrees C with (thermoneutral, TN groups) or for 16 h/d at 22 degrees C and for 8 h/d (09.00 am to 05.00 pm) at 34 degrees C (heat stress, HS groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein per kg of diet. Heat exposure decreased birds' performance when basal diet was fed. Increase in feed intake and body weight, and improvement of feed efficiency and carcass traits were found in genistein-supplemented quails reared under heat stress conditions. Growth rate and feed efficiency improved in quails reared under thermo-neutral conditions as well. Concentration of serum vitamins C, E, and A increased in supplemented birds reared at high temperature, while non-significant changes occurred in TN groups. With genistein supplementation homocysteine levels in serum and MDA levels in serum and liver decreased in all birds of both TN and HS groups. Effects of genistein were relatively greater in heat-stressed quails than in quails kept under thermo-neutral conditions. Results of the present study suggest that supplementation with genistein can be considered to be protective by reducing the negative effects of oxidative stress induced by heat stress in quail.

The role of the carboxyl-terminal fragments of amyloid precursor protein in Alzheimer's disease.

Two major pathological hallmarks of Alzheimer's disease (AD) are the senile plaques that are primarily composed of amyloid beta-peptide (Abeta) and neurofibrillary tangles consisting of tau aggregates. Abeta is generated proteolytically from a family of Abeta-containing precursor proteins (APP; 695-770 amino acid) by secretase enzymes to different specific carboxyl-terminal fragments (CTFs). Herein we examined APP and its products in autopsied brain sections from 10 AD and 10 non-AD control subjects immunochemically using an antibody that was raised against APP751-770 residue (O443). The O443 antibody was initially characterized by Western blot analysis and immunoprecipitation. In this study, we used this antibody for immunohistochemical analysis to determine the distribution of APP and its CTF species. In 10 brain regions showing different levels of plaques and tangles, antibody O443 stained the perinuclear region of the nucleus, plaques, and neurites. Tangle-bearing neurons also appeared to stain with the antibody, suggesting that these dysfunctional neurons continue to synthesize APP/CTF. Alternatively, the normally short-lived APP/CTF can be stabilized and persist in these neurons. Taken together, these results suggest that, in addition to the widely believed role of Abeta, CTFs may play a key role in the pathogenesis of AD. Studying their localization and biogenesis may reveal the biological activities of CTFs of APP. The present study may pave the way for possible antiamyloidogenic therapy in the treatment of AD.

Expression of ERRP in normal and neoplastic pancreata and its relationship to clinicopathologic parameters in pancreatic adenocarcinoma.

INTRODUCTION AND AIMS: Epidermal growth factor (EGF) and its receptor (EGFR) play crucial roles in cellular signaling in many malignancies, including pancreatic neoplasia. Attenuation of EGFR signaling has been considered novel strategy for the management of human malignancies in several ongoing clinical trials. We recently isolated a novel negative regulator of EGFR, termed EGF receptor related protein (ERRP), whose expression appears to attenuate EGFR activation. In the current study, the expression of ERRP in normal and neoplastic pancreas was investigated and correlated with the clinicopathologic parameters in pancreatic ductal adenocarcinoma (DA). METHODOLOGY: Using rabbit polyclonal antibody that specifically interacts with ERRP, immunohistochemical staining was performed on 45 benign pancreata and 106 cases of DA. The intensity and percentage of cells with cytoplasmic and membranous staining were scored as 0, 1, 2, or 3. A combined score was calculated as intensity x percent/3, and for comparative analysis, the data were arbitrarily divided into three groups: <20, 20-49, and > or =50. The expression of ERRP was correlated with patient age, gender, race, tumor size, stage, grade, and survival. RESULTS: ERRP was expressed in most benign ductal epithelium and islet cells, but not in normal acinar cells. In pancreatic ductal adenocarcinoma, ERRP expression frequency decreased progressively from well (WD) to moderate (MD) to poorly differentiated (PD) carcinoma (58%, 43%, and 15% respectively, < 0.001). ERRP expression was correlated with survival in DA showing decreased median survival with decreased ERRP score ( = 0.0035). Median survival of the lower intensity (0 or 1) group was less than that of the higher intensity (2 or 3) group (8 14 months, = 0.002). The higher expressing group (> or =50% of cells) had longer median survival (17 months) than the lower expressing (<50% of cells) group (10 months, = 0.003). Stepwise multiple regression analyses revealed that ERRP expression score and tumor grade are the significant predictors of survival in pancreatic ductal carcinomas ( < 0.03). CONCLUSION: ERRP is usually expressed in benign ductal epithelium, but not in ductal adenocarcinoma. Its expression decreases with decreasing tumor differentiation. Low levels of ERRP are associated with poor clinical outcome, suggesting that progressive loss of ERRP, a negative regulator of EGFR, may partly stimulate aggressive tumor cell growth in pancreatic adenocarcinoma.

Genistein elicits pleiotropic molecular effects on head and neck cancer cells.

Genistein (4,5,7-trihydroxyisoflavone) has been reported to induce cell cycle arrest and apoptosis in different cancer cell lines in vitro and to show antitumor activity against a variety of tumors in animal models. We have previously reported (S. A. Alhasan et al., Nutr. Cancer, 34:12-19, 1999; S. A. Alhasan et al., Int. J. Oncol., 16: 333-338, 2000) that genistein induces cell cycle arrest and apoptosis by up-regulating p21(WAF1) and Bax, and down-regulating cyclin B1 and Bcl-2 in a head and neck cancer cell line. However, the precise molecular mechanism(s) by which genistein elicits its effects on head and neck cancer cells still remains to be elucidated. In the present study, we report that genistein induces several specific molecular changes in head and neck cancer cells, such as down-regulation of c-erbB-2 expression, down-regulation of MMP-2 and MMP-9 secretion, inhibition of tumor cell invasion and down-regulation of nuclear factor-kappaB DNA binding activity. In addition, genistein inhibited the levels of phosphorylated Akt and the expression of 14-3-3 protein. Moreover, genistein induces telomere shortening in treated cells without affecting telomerase activity in vitro. We also observed that genistein inhibits the translocation of telomerase catalytic subunit [human telomerase reverse transcriptase (hTERT)] to the nucleus, which may result in telomere shortening, although the activity of telomerase is unaffected, along with the inhibition of metaphase spread of chromosomes. From these results, together with our previously published reports, (S. A. Alhasan et al., Nutr. Cancer, 34: 12-19, 1999; S. A. Alhasan et al., Int. J. Oncol., 16: 333-338, 2000) we conclude that genistein elicits pleiotropic molecular changes that resulting in the inhibition of cell growth and the induction of apoptotic cell death of head and neck cancer cells, which suggests that genistein may be useful as a chemotherapeutic and/or chemopreventive agent for head and neck cancer.

Structural alteration of p53 protein in patients with muscle invasive bladder transitional cell carcinoma.

PURPOSE: Recent data imply that 3-dimensional (D) p53 protein modeling provides more specific information on its function in patients with pancreatic adenocarcinoma. In addition to immunohistochemical and single strand conformational polymorphism analysis, we performed 3-D p53 protein modeling and correlated our results with the disease-free survival of patients with muscle invasive transitional cell carcinoma of the bladder who underwent surgery. MATERIALS AND METHODS: We identified 43 patients and analyzed p53 status in each by immunohistochemical testing, single strand conformational polymorphism and DNA sequencing with 3-D protein modeling. Median followup was 38 months (range 4 to 92). The results of each analysis were compared and correlated with cancer specific survival. Statistical analysis was performed using the log rank test on Kaplan-Meier survival curves. RESULTS: The population included 30 men and 13 women 35 to 84 years old (median age 65). Nuclear over expression of p53 protein was observed in 26 of the 43 cases (60%). Lymph node involvement did not correlate with p53 over expression. Significantly more patients with lymph node metastasis died of cancer. Median survival in the 26 patients with p53 over expression was 28 months versus 57 in those with negative staining (p = 0.25). Mutation analysis by single strand conformational polymorphism revealed no abnormality in 24 patients (56%) with a median survival of 28 months, whereas we noted abnormal mutational analysis in 19 (44%) with a median survival of 38 months (p = 0.33). Of 19 single strand conformational polymorphism positive cases DNA sequencing showed mutation near the DNA binding site in 10 (53%), mutation away from the site in 6 (32%) and no mutation in 3 (17%). No survival difference was detected in cases with mutation away and near the DNA binding site, respectively (p = 0.69). CONCLUSIONS: In this group of patients treated with radical cystectomy for muscle invasive bladder transitional cell carcinoma, analysis of p53 protein and the p53 gene by immunohistochemical testing, single strand conformational polymorphism and mutational analysis did not correlate with cancer specific survival.

Bryostatin 1 induces differentiation and potentiates the antitumor effect of Auristatin PE in a human pancreatic tumor (PANC-1) xenograft model.

Pancreatic cancer has the worst prognosis of all cancers with a dismal 5-year survival rate. Hence, there is a tremendous need for development of new and effective therapy for this tumor. In an earlier study we reported a potent antitumor activity of Auristatin PE (AuriPE) against pancreatic tumor. In addition, we have also reported that bryostatin 1 (bryo1) induces differentiation of leukemia cells, but the effect of bryo1 has not been investigated in pancreatic tumors. This is the first report where we demonstrate that bryo1 induces differentiation and potentiates the antitumor effect of AuriPE in a human pancreatic tumor (PANC-1) xenograft model. A xenograft model was established by injecting the PANC-1 cells s.c. in severe combined immune deficient (SCID) mice. After development of the s.c. tumors, tumors were dissected and small fragments were transplanted in vivo to new SCID mice, with a success rate of 100% and a doubling time of 4.8 days. The SCID mouse xenograft model was used to test the in vivo differentiation effect of bryo1 and its efficacy when given alone or in combination with AuriPE. Sections from paraffin-embedded tumors excised from untreated (control) SCID mice revealed typical poorly differentiated adenocarcinoma of the pancreas. Interestingly, sections of s.c. tumors taken from bryo1-treated mice revealed carcinomas that were much lower grade and less aggressive, and displayed prominent squamous and glandular differentiation. In this study, the tumor growth inhibition (T/C), activity score and cure rate for bryo1, AuriPE and bryo1+AuriPE were 80%, (+) and 0/4; 0.0%, (++++) and 3/5; and 0.0%, (++++) and 3/4, respectively. Mice treated with either AuriPE or bryo1+AuriPE were free of tumors for more than 150 days and were considered cured. The use of bryo1 as a novel differentiating agent and its combination with AuriPE should be further explored for the treatment of adenocarcinoma of the pancreas.

Expression of inflammatory modulator COX-2 in pancreatic ductal adenocarcinoma and its relationship to pathologic and clinical parameters.

Despite the exceedingly poor prognosis of pancreatic cancer, it is often histologically well to moderately differentiated. The apparent resistance to conventional therapeutic modalities is poorly understood and may be related to the molecules involved in its progression or its propensity for perineurial invasion. Cyclooxygenase-2 (COX-2) is an inducible enzyme homologous to COX-1 that is responsible for production of prostaglandins at sites of inflammation. It is activated by a variety of growth factors and tumor promoters, and it has been implicated in cancer progression. It may also have a role in the resistance to therapy. Anti-COX-2 agents have been documented to have antitumor activity, and some are now being tested in the therapy for various cancers, including those of the pancreas. Experience regarding the rate of COX-2 expression in pancreatic cancer and its relationship to the clinical and biologic parameters is very limited. In this study, immunohistochemical stains for COX-2 have been performed on 120 cases of pancreatic ductal adenocarcinoma. The stains were scored according to the percentage (0: no staining, 1: < 10%, 2: 10-50%, and 3: >50% of the cells staining) and intensity (0 for no staining, 1 for mild staining, and 2 for dark staining) of staining. Based on the combined score for each case, they were divided into low expressors (percentage and intensity < or =1) and high expressors (percentage or intensity >1). In addition to global scoring for each case, the glandular and solid (poorly differentiated) components, when present, were scored separately. The global scores were correlated with clinical and biologic parameters. Seventy-four percent of the cases exhibited expression of COX-2 and 53% were high expressors. No significant association was observed when comparing the global COX-2 expression to survival, tumor size, stage, and vascular invasion. Increased perineural invasion was found to be significantly associated with COX-2 expression (p < 0.05). Increased expression was also more common in the glandular component as compared with the solid component of the tumors (68% versus 35%, p < 0.05). Of the 34 patients who received radiotherapy, 9 were low expressor (median survival 19.5 months) and 25 were high expressors (median survival 14 months). The difference in survival was not statistically significant.

Zinc activates NF-kappaB in HUT-78 cells.

Zinc is essential for human health, and its deficiency in human beings results in growth failure, immune disorders affecting Th1 functions, decreased interleukin-2 (IL-2) production, and cognitive impairment. Nearly 2000 transcription factors require zinc for their structural integrity; however, it is not known whether cellular zinc deficiency results in any change in activation of any of the transcription factors. Inasmuch as NF-kappaB binds to the promoter enhancer area of IL-2 and IL-2Ralpha genes, we investigated the effect of zinc deficiency on activation of NF-kappaB and its binding to DNA in HUT-78, a Th0 malignant human lymphoblastoid cell line. We show here for the first time that in zinc-deficient HUT-78 cells, phosphorylated IkappaB, and IKK, ubiquitinated IkappaB and binding of NF-kappaB to DNA were all significantly decreased. Zinc increased the translocation of NF-kappaB from cytosol to nucleus. We also demonstrate that the binding of recombinant NF-kappaB (p50)(2) to DNA in HUT-78 cells was zinc specific. We conclude that zinc plays an important role in the activation of NF-kappaB in HUT-78 cells.

Molecular analysis of p53 and K-ras in lung carcinomas of coal miners.

Thirty-three cases of non-small cell lung cancers (NSCLC) from the archives of National Coal Workers' Autopsy Study were studied for mutational alterations in p53 and K-ras using PCR-SSCP, DNA sequencing and PCR-oligonucleotide probe hybridization techniques. Mutations of the p53 were observed in 4 smokers (19%) and one in a never smoker (8%). Two polymorphisms in smokers were detected at codon 213, a common site for sequence variation. Among the smokers the p53 mutations were in the heavy smokers. In never smokers there was only a single p53 mutation and two K-ras mutations. In never smokers the frequency of K-ras mutations was similar (17%) in smokers, but one never smoker had two K-ras mutations. Mutations of p53 were more frequent in adenocarcinomas (27%) and they were AT-->GC transitions. Four of 11 (36%) adenocarcinomas were found to have K-ras codon 12 mutations, and one adenocarcinoma had two K-ras mutations. There were two large cell undifferentiated carcinomas with p53 mutation and one with a K-ras mutation. Two of the 16 squamous cell carcinomas were positive for p53 mutation, while no K-ras mutations were found in this group. The results of these preliminary studies indicate a moderately different mutational spectrum of p53 and K-ras in coal miners independent of cigarette smoking. The mutational spectrum observed in this study of coal miners with heavy cigarette smoking history suggest a protective effect of coal mine dust in preventing abnormal mutations induced by chemical carcinogens in cigarette smoke or reactive oxygen species. These limited preliminary studies provide insight into the possibility of accurately measuring changes in etiologic markers to unravel the uncertainties of cancer in coal miners.