30259650
Cell signaling and regulators of cell cycle as molecular targets for prostate cancer prevention by dietary agents.
Prostate cancer (PCA) is the most common invasive malignancy and leading cause (after lung) of cancer deaths in males. Since PCA is initially androgen-dependent, strategies are targeted toward androgen depletion for its control. However, tumor re-growth mostly occurs following this modality, and is androgen-independent. A loss of functional androgen receptor and an enhanced expression of growth factor receptors (e.g. erbB family members) and associated ligands have been shown to be the causal genetic events in PCA progression. These genetic alterations lead to an epigenetic mechanism where a feed-back autocrine loop between membrane receptor (e.g. epidermal growth factor receptor [erbB1] and associated ligand (e.g. transforming growth factor-alpha) results in an enhanced activation of extracellular signal-regulated protein kinase 1/2 (ERK1/2) as an essential component of the uncontrolled growth of PCA at an advanced and androgen-independent stage. Together, we rationalized that inhibiting these epigenetic events would be useful in controlling advanced PCA growth. Dietary polyphenolic flavonoids and isoflavones are being studied extensively as cancer-preventive and interventive agents. Therefore, we focused our attention on silymarin, genistein, and epigallocatechin 3-gallate (EGCG), present in milk thistle, soy beans, and green tea, respectively. The effect of these agents was assessed on the erbB1-Shc-ERK1/2 signal transduction pathway, cell cycle regulatory molecules, and cell growth and death. In androgen-independent human prostate carcinoma DU145 cells, silymarin, genistein, and EGCG resulted in a significant to complete inhibition of transforming growth factor-alpha-caused activation of membrane receptor erbB1 followed by inhibition of downstream cytoplasmic signaling target Shc activation and a decrease in its binding with erbB1, without an alteration in their protein expression. Silymarin and genistein also inhibited ERK1/2 activation, suggesting that these agents impair the activation of erbB1-Shc-ERK1/2 signaling in DU145 cells. In the case of EGCG, a further increase in ERK1/2 activation was observed that was related to its pro-oxidant and apoptotic activities. Silymarin, genistein, and EGCG also resulted in a significant induction of Cip1/p21 and Kip1/p27 and a decrease in cyclin-dependent kinase (CDK) 4, but a moderate inhibition of CDK2, cyclin D1, and cyclin E was observed. An enhanced level of Cip1/p21 and Kip1/27 also led to an increase in their binding to CDK4 and CDK2. Treatment of cells with silymarin, genistein, and EGCG also resulted in strong cell growth inhibition at lower doses, and complete inhibition at higher doses. In contrast to silymarin, higher doses of genistein also showed cell death. A more profound cytotoxic effect was observed in the case of EGCG, with strong cell death at lower doses and complete loss of viability at higher doses. Together, these results suggest that cell signaling and regulators of cell cycle are potential epigenetic molecular targets for prostate cancer prevention by dietary agents. More studies, therefore, are needed with these agents to explore their anticarcinogenic potential against human prostate cancer.
37464296
Introduction to Special Issue on Molecular Basis for Cancer Prevention with Bioactive Food Components in Nutrition and Cancer--an International Journal.
The advance of technology and understanding of the process of cancer development suggests that the reported lesser incidence and death due to cancer in countries other than the Western and European countries might also be due to under- diagnosed and under-represented cases. Further, increases in life span as well as ignorance about the disease puts populations in South and South East Asian countries at higher risk to develop cancer. With the increasing rate of cancer incidence every year in non -Western countries, cancer is estimated to become the deadliest disease in coming decades. Conventional chemo- and radio-therapies during the past three decades have not been able to contain the disease, and also have serious side effects. Many natural agents, especially small molecules from plants are non-toxic, easily available and may have anticancer potential. Thus, screening phytochemicals as anticancer agents could be a better approach in cancer prevention and treatment. This chemoprevention approach may have translational significance for prevention and treatment of cancer. 
 
Therefore to emphasize the potential role of phytochemicals in cancer prevention and therapy, it was our privilege to host the International Symposium on Recent Advances in Cancer Research: Therapeutics to Chemoprevention, at Central University of Gujarat (CUG), Gandhinagar. The conference was co-organized by the University of Colorado Denver, USA; University of Pittsburgh, USA; University of Oklahoma, USA, during 8–9 February, 2012. Modern biological strategies, specifically the latest developments for the targeted prevention and treatment of cancer via dietary, natural and synthetic agents were discussed in detail. The symposium also emphasized the translational aspect of cancer chemoprevention strategies for various cancers. 
 
The symposium deliberations include the ideas for combinatorial chemoprevention by phytochemicals as a promising approach for cancer control and emerging trends for the use of herbal radio-modulators to sensitize the cancer cells for apoptotic cell death. Many bioactive phytochemicals such as silibinin, benzyl isothiocyanate, anthocyanidins, nexrutine, tocopherol, etc. were discussed for their in vivo efficacy in animal tumor models, associated mechanisms and translational potential. Targeting tumor microenvironment with small molecules was found promising and having translational potential for prostate and breast cancer chemoprevention. 
 
The novel work and ideas presented at the symposium were helpful in guiding the research orientation of scientists, especially the young researchers who will be benefitted at all levels of their career development. Since chemoprevention of cancer is becoming an attractive approach for controlling cancer, we felt that the deliberations of this symposium should reach to the wider section of the researchers. Therefore, it was planned to bring out a special issue on Molecular Basis for Cancer Prevention with Bioactive Food Components in Nutrition and Cancer – An International Journal. We appreciate the researchers for contributing their novel work and ideas to this special issue. We are grateful to the Editor of Nutrition and Cancer – An International Journal, for his initiative to bring out this special issue on this relevant topic. We believe that this volume will be enlightening for the researchers working in the area of cancer chemoprevention.
6837472
Apoptosis is an early event during phthalocyanine photodynamic therapy-induced ablation of chemically induced squamous papillomas in mouse skin.
Photodynamic therapy (PDT) is a promising new modality to treat malignant neoplasms including superficial skin cancers. In our search for an ideal photosensitizer for PDT, Pc 4, a silicon phthalocyanine, has shown promising results both in in vitro assays and in implanted tumors. In this study we assessed the efficacy of Pc 4 PDT in the ablation of murine skin tumors; and the evidence for apoptosis during tumor ablation was also obtained. The Pc 4 was administered through tail vein injection to SENCAR mice bearing chemically induced squamous papillomas, and 24 h later the lesions were illuminated with an argon ion-pumped dye laser tuned at 675 nm for a total light dose of 135 J/cm2. Within 72-96 h, almost complete tumor shrinkage occurred; no tumor regrowth was observed up to 90 days post-PDT. As evident by nucleosome-size DNA fragmentation, appearance of apoptotic bodies in hematoxylin and eosin staining and direct immunoperoxidase detection of digoxigenin-labeled genomic DNA in sections, apoptosis was clearly evident 6 h post-PDT at which time tumor shrinkage was less than 30%. The apoptotic bodies, as evident by the condensation of chromatin material around the periphery of the nucleus and increased vacuolization of the cytoplasm, were also observed in electron microscopic studies of the tumor tissues following Pc 4 PDT. The extent of apoptosis was greater at 15 h than at 6 and 10 h post-PDT. Taken together, our results clearly show that Pc 4 may be an effective photosensitizer for PDT of nonmelanoma skin cancer, and that apoptosis is an early event during this process.
46117096
ras protein p21 processing enzyme farnesyltransferase in chemical carcinogen-induced murine skin tumors.
Farnesylation of ras protein p21 is crucial for the protein's membrane localization, which is essential for its cell-transforming activity, which in turn is thought to be critical for the ultimate induction of cancer. The cytosolic enzyme farnesyltransferase plays a major role in posttranslational modification of p21, but the level of farnesyltransferase activity in mammalian tumors and its relationship to the processing of cytosolic p21 that leads to tumorigenesis are unknown. We report here that farnesyltransferase activity was significantly higher in chemical carcinogen-induced benign skin papillomas in SENCAR mice than in the epidermises of control animals. The enzyme is primarily epidermal in origin, and kinetic studies with cytosol from epidermis and papillomas showed that the reaction was linear with respect to time, substrate concentration, and protein content. Skin papillomas showed significantly elevated levels of both cytosolic and membrane-bound Ha-ras p21, whereas far lesser cytosolic and almost negligible amounts of membrane-bound p21 were present in the epidermis of control mice. There was a positive correlation between increased enzyme activity in papilloma cytosol and the processing of overexpressed cytosolic Ha-ras p21 for its localization to membrane.
35457752
Nordihydroguaiaretic acid, an inhibitor of lipoxygenase, also inhibits cytochrome P-450-mediated monooxygenase activity in rat epidermal and hepatic microsomes.
Nordihydroguaiaretic acid (NDGA), a plant lignan and phenolic antioxidant, is a known lipoxygenase inhibitor. In this study, we investigated the effect of NDGA on rat epidermal and hepatic monooxygenase activity and its interaction with rat hepatic microsomal cytochrome P-450. The addition of NDGA to epidermal microsomes prepared from control and 3-methylcholanthrene (3-MC)-pretreated rats and hepatic microsomal preparations from control, 3-MC-pretreated, and phenobarbital (PB)-pretreated rats resulted in a concentration-dependent inhibition of aryl hydrocarbon hydroxylase (AHH) and 7-ethoxyresorufin O-deethylase (ERD) activities. The 50% inhibitory dose for NDGA ranged from 4.1 x 10(-5) to 13.1 x 10(-5) M for AHH and ERD activities in these microsomal preparations. The addition of NDGA to hepatic microsomes prepared from PB-pretreated rats resulted in spectral changes characterized by absorbance maxima at 380 nm and minima at 414 nm, typical of type I binding difference spectra. It also showed time- and concentration-dependent inhibition of the binding of carbon monoxide to dithionite or NADPH-reduced cytochrome P-450. We speculate that perhaps hydroxyl groups present in NDGA play an important role in inhibiting the monooxygenase activity and suggest that NDGA may have potential as an antimutagen and/or anticarcinogen. Furthermore, caution must be exercised in elucidating the role of lipoxygenase in metabolic pathways based solely on the criterion of inhibition by NDGA.
5785486
Identification of the site of photocross-linking formed in the absence of magnesium nucleotide from SH2 (Cys-697) in myosin subfragment 1 labeled with 4'-maleimidylbenzophenone.
The site of photocross-linking between Cys-697 (SH2), prelabeled with 4'-[14C]maleimidylbenzophenone, and the 50-kDa segment of myosin S1 on irradiation in the absence of nucleotide has been determined by isolation of the 20-50-kDa adduct and subsequent tryptic proteolysis. Isolation and partial sequencing of the radioactively labeled peptide indicate that the site of cross-linking is Arg-239. This result indicates that, in the absence of nucleotide, Arg-239 resides at about 1.0 nm from SH2 and, on the basis of the recent work of Sutoh and Hiratsuka (Sutoh, K. and Hiratsuka T. (1988) Biochemistry 27, 2964-2969) places Arg-239 at no more than 1.45 nm from either Lys-184 or Lys-189 of the nucleotide-binding "glycine-rich" loop prior to the binding of nucleotide.
6343189
Mechanisms of angiotensin converting enzyme inhibitor-induced IOP reduction in normotensive rats.
Angiotensin converting enzyme inhibitors (ACEIs) have been shown to lower intraocular pressure (IOP). Since, the ACEIs cause increased tissue prostaglandin levels, we hypothesized that the mechanisms of ACEI-induced IOP reduction have similarity with those of prostaglandin analogs. The present study investigated the involvement of matrix metalloproteinases (MMPs) and cytokine activity modulation as the underlying mechanisms of ACEI-induced ocular hypotension. The IOP lowering effect of single drop of enalaprilat dehydrate 1% was evaluated in rats pretreated with a broad spectrum MMP inhibitor or a cytokine inhibitor. Effect of angiotensin receptor blocker, losartan potassium 2%, was also studied to evaluate involvement of angiotensin II receptor type 1 (AT1) in IOP lowering effect of ACEI. Topical treatment with single drop of enalaprilat resulted in significant IOP reduction in treated eye with mean peak reduction 20.3% at 3h post-instillation. Treatment with losartan resulted in a peak IOP reduction of 13.3%, which was significantly lower than enalaprilat, indicating involvement of mechanisms in addition to AT1 blockade. Pretreatment with a broad spectrum MMP inhibitor or a cytokine inhibitor significantly attenuated the enalprilat-induced IOP reduction with mean peak IOP reduction of 11.2% and 13.6% respectively. The IOP-lowering effect of enalaprilat seems to be attributed to reduced angiotensin II type 1 receptor stimulation and modulation of MMP and cytokines activities.
8134220
Prognostic factors in ovarian cancer: how close are we to a complete picture?
Prognostic factors in ovarian cancer: how close are we to a complete picture? Ovarian cancer is the fourth most common cause of cancer-related death in women, but is the most lethal of the gynaeco-logical malignancies with 30–40% overall survival at 5 years [1]. This is in part because the majority of patients with ova-rian cancer present with advanced disease, and treatment options at presentation are confined to a combination of debulking surgery and platinum based chemotherapy, which are only partially effective [2]. Consequently, almost all patients with advanced disease ultimately relapse and die of their disease. Advances in the management of these patients are therefore urgently required. Prognostic factors are defined as phenotypes which correlate with overall survival. In general prognostic factors reflect the intrinsic biology of a tumour (e.g. histological subtype, grade), disease extent (e.g. stage) and/or the capacity of a patient to cope with the morbidity associated with the tumour and treatment (e.g. performance status). As well as these pretreatment factors, others which may impact on outcome include the treatment received by a patient (e.g. optimal surgical cytore-duction, platinum-based chemotherapy), and the effect of treatment on the tumour (e.g. complete response) or the patient (e.g. myelosuppression). As clinical tools, prognostic factors can potentially help in individualising treatment for patients. In properly staged early disease (stage Ia/b), patients have a better prognosis and the benefits of adjuvant chemotherapy may be confined to those with adverse features (e.g. histological subtype or grade) [3]. In this context a prognostic factor with a good positive or negative predictive value for individual patients, would be useful in deciding which patients should receive chemotherapy and those for whom the toxicity was not justified. In contrast, in advanced disease, the majority of patients benefit from paclitaxel –carboplatin chemotherapy and debulking surgery. As there are no established alternatives for patients with either good or poor prognosis, pretreatment prognostic stratification has little influence on clinical management [2]. Instead, pre-treatment markers predictive of response or resistance to individual cytotoxic drugs would be more useful in this context for treatment selection. As research tools, prognostic factors can help identify subgroups of patients with especially poor prognosis and alert us to the need to develop alternative treatment strategies for these patients, while in clinical trials prognostic factors are used to balance patients between treatment arms to minimise the risk of confounding. Prognostic factor studies can also provide useful insights into …
207650194
Role of home blood pressure monitoring in overcoming therapeutic inertia and improving hypertension control: a systematic review and meta-analysis.
Hypertension remains the most common modifiable cardiovascular risk factor, yet hypertension control rates remain dismal. Home blood pressure (BP) monitoring has the potential to improve hypertension control. The purpose of this review was to quantify both the magnitude and mechanisms of benefit of home BP monitoring on BP reduction. Using a structured review, studies were selected if they reported either changes in BP or percentage of participants achieving a pre-established BP goal between randomized groups using home-based and office-based BP measurements. A random-effects model was used to estimate the magnitude of benefit and relative risk. The search yielded 37 randomized controlled trials with 9446 participants that contributed data for this meta-analysis. Compared with clinic-based measurements (control group), systolic BP improved with home-based BP monitoring (-2.63 mm Hg; 95% CI, -4.24, -1.02); diastolic BP also showed improvement (-1.68 mm Hg; 95% CI, -2.58, -0.79). Reductions in home BP monitoring-based therapy were greater when telemonitoring was used. Home BP monitoring led to more frequent antihypertensive medication reductions (relative risk, 2.02 [95% CI, 1.32 to 3.11]) and was associated with less therapeutic inertia defined as unchanged medication despite elevated BP (relative risk for unchanged medication, 0.82 [95% CI, 0.68 to 0.99]). Compared with clinic BP monitoring alone, home BP monitoring has the potential to overcome therapeutic inertia and lead to a small but significant reduction in systolic and diastolic BP. Hypertension control with home BP monitoring can be enhanced further when accompanied by plans to monitor and treat elevated BP such as through telemonitoring.
45728668
Pulmonary mucormycosis: two of a kind.
Mucormycosis is an uncommon infection caused by fungi of the class Zygomycetes, suborder Mucorales. It occurs predominantly in the immunodeficient host, the most common risk factor being diabetes mellitus. Pulmonary mucormycosis is a disease that is localized in the lungs or mediastinum. It usually presents in a fulminant manner, although a chronic presentation can also occur. We describe two cases of pulmonary mucormycosis in patients with diabetes mellitus, one with an acute and the other with a chronic presentation. A high level of clinical suspicion, combined surgical and medical therapy, and control of patient's underlying immunosuppression are the key to a successful outcome.
34975041
Treatment of hypertension in patients with diabetes: lessons from recent trials.
Hypertension plays a critical role in causing a high rate of cardiovascular events in patients with diabetes mellitus. Large trials show that lowering blood pressure in the patient with diabetes who has hypertension has profoundly favorable effects. This review discusses recent trials to answer the question of how low patients' blood pressure should go and which agents should be used to achieve this goal. The National Institutes of Health's guidelines, published in the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, call for a blood pressure goal of <130/85 mmHg in patients with diabetes. Based on data from the recent trials, an even lower blood pressure of <130/80 mmHg in patients with diabetes and hypertension appears to be appropriate. Observational studies show that the lowest cardiovascular event rate is observed in patients with diabetes whose systolic blood pressure is <120 mmHg. Thus, goal blood pressure in patients with diabetes who have hypertension may need to be revised lower, to <120/80 mmHg. In patients with overt proteinuria of 1 g/d or more, mean arterial pressure of <92 mmHg is recommended. Available evidence justifies the use of angiotensin-converting enzyme (ACE) inhibitors as first-line agents and angiotensin receptor blockers in those patients who are intolerant to ACE inhibitors. Because the blood pressure goal is lower in patients with diabetes who are hypertensive, these patients require the use of multiple agents. Diuretics or long-acting calcium channel blockers are logical second choices because of their synergistic blood pressure reduction effect observed with ACE inhibitors. Alpha-blockers should be used with caution, however. In patients with renal disease, loop diuretics may be required to reduce sodium and volume overload and to improve blood pressure control.