Munendra Singh Tomar

Carboxylic group-induced synthesis and characterization of selenium nanoparticles and its anti-tumor potential on Dalton's lymphoma cells

Carboxylic group-induced synthesis of selenium nanoparticles (SeNPs) was achieved using sodium selenosulphate as a precursor. The particles were stabilized and capped with 0.01% polyvinyl alcohol under ambient conditions. This is a simple and easy method of producing SeNPs in a size range from 35 to 105 nm. The synthesized SeNPs were purified by centrifugation at 11,500 × g for 20 min and characterized by UV-visible spectroscopy, FTIR spectroscopy, XRD, DSC and TEM. It was observed that the synthesized SeNPs showed differences in their absorption spectra, phase composition and crystal structure, thermodynamic behaviour, size and shape. Further, to confirm anti-tumour potential of the synthesized SeNPs induced by the carboxylic group of acetic acid, pyruvic acid and benzoic acid, cell viability assay, nuclear morphology testing and DNA fragmentation assay were carried out using Daltons lymphoma (DL) cells. DL cells treated with the SeNPs showed reduced cell viability, altered nuclear morphology, typical apoptotic DNA ladder and apoptosis. Therefore, these SeNPs may have therapeutic relevance to treat this type of cancer.

HSF1-mediated regulation of tumor cell apoptosis: a novel target for cancer therapeutics

Programmed cell death/apoptosis is a genetically conserved phenomenon involved in many biological processes including reconstruction of multicellular organisms and elimination of old or damaged cells. It is regulated by the activation/deactivation of PKC in response to exogenous and endogenous stimuli. PKC is activated under stress by a series of downstream signaling cascades, which ultimately induce HSF1 activation, which results in overexpression of heat shock proteins. Overexpression of heat shock proteins interferes in the apoptotic pathway, while their blocking results in apoptosis. Therefore, HSF1 could be a novel therapeutic target against a variety of tumors. Several pharmacological inhibitors of PKC have been demonstrated to exert inhibitory effects on the activation of HSF1 and, therefore, induce apoptosis in tumor cells. However, studies regarding the role of pharmacological inhibitors in the regulation of apoptosis and possible anti-tumor therapeutic intervention are still unknown or in their infancy. Therefore, an attempt has been made to delineate the precise role of HSF1 in the regulation of apoptosis and its prospects in cancer therapeutics.

Activation of p53-dependent/-independent pathways of apoptotic cell death by chelerythrine in a murine T cell lymphoma

Abstract The p53 tumor suppressor protein has been implicated as an activator of apoptosis. In order to investigate the effect of chelerythrine and staurosporine on the activation of p53-dependent/-independent pathways of Dalton lymphoma (DL) cell death, cells were treated with chelerythrine and staurosporine for 1 h, 3 h and 6 h, respectively. It was found that treatment with chelerythrine and staurosporine increased the expression of total-p53/phospho-53 (ser-15) significantly at protein and mRNA levels, which resulted in activation of the p53-dependent apoptotic pathway in DL cells. In addition, increased activities of cyt-c, caspase-9 and caspase-3 and degradation of DNA into fragments confirmed activation of the p53-independent apoptotic pathway in p53 knockdown RNAi-DL cells. In brief, the present study demonstrated activation of p53-dependent/-independent apoptotic pathways in DL cells. Therefore, targeting of p53-dependent/-independent apoptotic pathways may lead to the possibility of designing and developing better therapeutic regimens to treat DL and other human cancers.

Progressive growth of a murine T cell lymphoma alters population kinetics and cell viability of macrophages in a tumor-bearing host

Tumor progression induces infiltration of immune cell populations at the site of tumor growth. Infiltrated leukocyte population including monocyte and macrophages interacts with tumor cells and tumor microenvironment and results in the suppression of macrophage functions. Impaired functions of macrophages result in the suppression/inhibition of cell-mediated immunity leading to inefficient antitumor immune responses. Impaired macrophage population invariably helps in immune selection of tumor leading to uninterrupted growth and progression in the host. Murine T cell lymphoma designated as Dalton’s lymphoma is highly immunosuppressive and invasive tumor of T cell origin, which completely paralyzes the host’s immune system resulting in a very short life span of the host. Progressive growth of Dalton’s lymphoma (DL) cells has been known to inhibit the release of inflammatory cytokines and effector mediator molecules. In this study, we demonstrate that intraperitoneal transplant of DL cells in normal healthy host induces a rapid increase in macrophage cell population during early stage of tumor progression and progressive decrease in tumor-associated macrophage population and reduced survival of macrophages in advance stage of tumor burden.

Selenium nanoparticles induce suppressed function of tumor associated macrophages and inhibit Dalton's lymphoma proliferation

Selenium Nanoparticle (SeNPs) is reported that it enhances and maintains optimal immune during infection and malignancies. To this end, we examined the role of selenium on TAMS whose anti-tumor function suppressed which favor tumor progression. BALB/c (H2d) strain of mice non-Hodgkin type of Daltons cell line was used to check the role of carboxlic group induced, synthesized SeNPs on TAMs. Screening of IC50 value was done primarily trypen blue exclusion assay and 50% proliferation of DL cells inhibited 40 ng/ml to 50 ng/. Treatment also decreases ΔΨm, fragmentation of DNA of DL cells and arrest cells cycle in G1/G0 phage. Untreated TAMs cells showing suppressed expression of ROS, adhesion, phagocytosis, fusion and receptor profiling such as ICAM-1, CD47, CD172α. Which was induced more as compare to untreated group. SeNPs have potential to induce the anti-tumor function of TAMs whose anti-tumor function down-regulated pliable shifted towards tumor progression. It decreased the proliferation of DL cell by inducing apoptosis. Therefore, the synthesized SeNPs could be used for imaging diagnosis and cancer therapy which must be cost effective with negligible side effects shifted towards tumor progression. It decreased the proliferation of DL cell by inducing apoptosis.

Chelerythrine delayed tumor growth and increased survival duration of Dalton's lymphoma bearing BALB/c H(2d) mice by activation of NK cells in vivo.

AIM The aims of the present investigation were to evaluate the antitumor effect of chelerythrine (CHE) on in vivo growth and survival duration of BALB/c (H2d) mice bearing Daltons lymphoma (DL) and enhanced function of tumor associated NK cells (TANK cells). MATERIALS AND METHODS BALB/c (H2d) mice at 8-10 weeks of age of either sex were used. Increasing concentration of CHE (1.25, 2.5, and 5.0 mg/kg), staurosporine (0.625, 1.0, 1.5, and 2.0 mg/kg) and cyclophosphamide (25, 50, 100, and 200 mg/kg) were administered intraperitoneally and tumor regression and survival duration of tumor bearing host were determined, and thereafter expression of NKG2D and NKG2A on TANK cells were detected. RESULTS Our results show that treatment with 2.5 mg/kg of CHE results in a significant reduction in mean tumor volume and increased survival duration of DL bearing BALB/c (H2d) mice when compared to control. Activating receptor NKG2D on TANK cells were observed upregulated in contrast to inhibitory receptor NKG2A. CONCLUSIONS CHE reduced mean tumor volume and increased survival duration of DL bearing BALB/c (H2d) mice. Increased expression of activating receptor NKG2D on TANK cells results in recovery of immunosuppression during tumor progression. Therefore, CHE could be a potential anticancer therapeutic agent that may be used to replace chemo-radio-therapy in future.

NK Cell Effector Functions Regulation by Modulating nTreg Cell Population During Progressive Growth of Dalton’s Lymphoma in Mice

ABSTRACT Natural killer (NK) cells are large granular lymphocytes of the innate immune system and play a pivotal role against virus-infected cells, microbial pathogens, and tumor cells. NK cells secrete several cytokine,s but IFN-γ secreted by NK cells play a vital role in the activation of the innate and adaptive immune systems. But during any infection or tumor burden, functional activity of NK cells is downregulated significantly by nTreg cells. It is also found that during tumor progression, the number of nTreg cells increases as a result; it effectively suppresses the antitumor activity of NK cells. Therefore, in the present investigation, we intend to examine the mechanism of downregulation of antitumor immune response mediated by NK cells. We observed increased NK cell population at an early stage of Dalton’s lymphoma (DL) growth, while at late stage, NK cell numbers were decreased. The NK cell functional activity was govern by high level of IFN-γ measurement during tumor progression. The FoxP3+ CD25+ CD4+ T regulatory cell population was found to be continuously increased with high-level expression of FoxP3 during DL growth. The rapid increase in the number of Treg cells during DL progression may be due to high level of the FoxP3 transcription factor. The tumor microenvironment of DL cell progression has highly deleterious effect on NK cells after massive growth of tumor burden in BALB/c mice. This result also indicates that NK cell proliferation, activation, and accumulation are under the control of regulatory T cells.

Classical Protein Kinase C: a novel kinase target in breast cancer

Classical protein kinase C (cPKC) enzymes are ser/thr protein kinases that have been an important factor in regulating a variety of cellular functions required for both in terms of health and disease. Therefore, precise control of cPKC-mediated signal is necessary for cellular homeostasis; however, their dysregulation leads to the development of several pathophysiological conditions including cancer. In cellular microenvironment, cPKC-mediated signaling is accompanied by multiple molecular mechanisms including phosphorylation, second messenger binding, and scaffold proteins. Functional cPKC interacts with a number of cellular proteins involved in the regulation of multiple biological functions such as cell growth, survival, migration, and adhesion. Further, the role of cPKC varies from cell to cell, substrate to substrate and, therefore, it is plausible to assume that the dysregulation of cPKC activity causes cellular transformation. Currently, there is no sufficient literature available to provide better understating to develop an effective therapeutic regimen to reverse pathophysiological condition caused by functionally dysregulated cPKC. Therefore, in the present review, we have focused on to provide a better and detail information on the various aspects of cPKC such as structure, mode of activation, regulation, and distinct cellular functions useful for the development of an effective therapeutic regimen against the breast cancer.

Biologically Synthesized Gold Nanoparticles using Ocimum sanctum (Tulsi Leaf Extract) Induced Anti-Tumor Response in a T Cell Daltons Lymphoma

The characterizations of green synthesized gold nanoparticles (AuNPs) prepared using Ocimum sanctum leaf extract were done by UV-Spectrophotometer at 500-540 nm. The XRD data obtained were found similar to gold JCPDS File No- 04-0784. SEM and TEM analysis of AuNPs revealed spherical shape and size of 200 nm. Further FT-IR data indicated the various biomolecules present in Ocimum sanctum leaf extract provides stability to gold nanoparticles synthesis. The AuNPs were studied for their anti-cancer activity on Dalton’s lymphoma (DL) cells and the results obtained with IC50 value of < 50 ng/ml performed by MTT assay. Further, to confirm anti-tumor potential and the mode of action of the synthesized AuNPs, cell viability assay, nuclear morphology, DNA fragmentation assay, mitochondrial membrane potential (ΔΨm) analysis, and cell cycle analysis were done using DL cells. DL cells treated with the AuNPs showed reduced cell viability, altered nuclear morphology, typical apoptotic DNA ladder formation and apoptosis. From the above finding it can be concluded that the AuNPs have potential to decrease the proliferation of tumor cells and enhanced the production of ROS. Gold nanoparticles used in cancer detection and diagnosis/treatment are mainly in preclinical stages of cancer development.

Protein kinase C-α and the regulation of diverse cell responses

Abstract Protein kinase C (PKC) comprises a family of lipid-sensitive enzymes that have been involved in a broad range of cellular functions. PKC-α is a member of classical PKC with ubiquitous expression and different cellular localization. This unique PKC isoform is activated by various signals which evoke lipid hydrolysis, after activation it interacts with various adapter proteins and is localized to specific cellular compartments where it is devised to work. The universal expression and activation by various stimuli make it a perfect player in uncountable cellular functions including differentiation, proliferation, apoptosis, cellular transformation, motility, adhesion and so on. However, these functions are not intrinsic properties of PKC-α, but depend on cell types and conditions. The activities of PKC-α are managed by the various pharmacological activators/inhibitors and antisense oligonucleotides. The aim of this review is to elaborate the structural feature, and provide an insight into the mechanism of PKC-α activation and regulation of its key biological functions in different cellular compartments to develop an effective pharmacological approach to regulate the PKC-α signal array.