Angiogenic and Metastatic Determinants of Malignant Melanoma

Cutaneous melanoma or malignant melanoma of the skin is a highly metastatic disease, with an increasing rate of incidence, poor prognosis and high resistance to therapeutic intervention. Although early diagnosis and surgical resection of the primary lesion could significantly improve survival, the high propensity of melanomas to disseminate through intradermal, haematogenous and lymphatic routes to regional and visceral sites leads to poor prognosis and high mortality rates. While the clinical staging and progression of melanoma is well defined, the molecular etiology of the disease is less well characterized. The principal goal of this thesis was to obtain novel mechanistic insights into melanoma biology and identify molecular determinants of this disease. We identified the capacity of melanoma-derived small molecules to promote long-term survival of endothelial cells under severe hypoxic conditions. This observation excludes known proangiogenic molecules which have been the focus of anti-angiogenic therapies and sets the stage for the identification of novel regulators with therapeutic potential. Moreover, TIMP3 was identified as a dominant negative regulator of melanoma development. The inhibitory role of TIMP3 in melanoma angiogenesis was validated and further extended to clinical samples from melanoma patients. We showed that promoter methylation mediated TIMP3 silencing impacts clinical outcome in melanoma and also evaluated the implications of the tumor suppressor role of TIMP3 in melanoma metastasis, using matched samples from melanoma patients. A decrease in TIMP3 expression with observed with disease progression and further TIMP3 inhibited melanoma cell migration and invasion. To characterize core mediators of the metastatic cascade of melanomas, we determined the migratory profile of melanoma cell lines and performed correlation analysis to identify potential genetic modulators. WNT5A was identified as a dominant regulator of the metastatic cascade in melanoma and further we show that WNT5A inhibition decreases the migratory and metastatic potential of melanoma cells. Additionally, this thesis describes novel tools to quantitatively characterize several biological processes. The ring barrier-based migration assay enables the quantitative assessment of several parameters of cell migration. The eNOS-Tag-GFP mouse model provides a platform for the in vivo and ex vivo study of early angiogenic events in physiological and pathological conditions. Collectively, the results presented in this thesis identify crucial pathophysiological determinants of melanoma. These insights and tools may further guide the discovery of novel regulators of melanoma biology and result in the implementation of new treatment rationales for therapeutic benefit

NATURAL PERMEATION ENHANCER FOR TRANSDERMAL DRUG DELIVERY SYSTEM AND PERMEATION EVALUATION: A REVIEW

The transdermal drug delivery route is evolving as a potential route due to its advantages of bypassing the hepatic first pass metabolism, decreased side effects and gastrointestinal effects, improve patience compliance as it is a pain-free self-administration for patients, etc. The major setback appearing in this route is the difficulty of the drugs to penetrate through the skin as the stratum corneum (outermost layer of the skin) forms a protective barrier for the underlying tissues from the outer environment. A transdermally delivered drug can only show its action when it can cross the transdermal barrier to reach the systemic circulation and for helping on doing that the penetration enhancer are the agents which increase the permeability of the skin which on return maintains the drug level in the blood. Permeation enhancers can be of a chemical type, natural type, and physical type. The present review describes the natural permeation enhancers can be which be employed for transdermal permeation of drugs.Â

FORMULATION AND EVALUATION OF TRANSDERMAL PATCH OF INDOMETHACIN CONTAINING PATCHOULI OIL AS NATURAL PENETRATION ENHANCER

  Objective: To develop a transdermal patch of Indomethacin using patchouli oil as a natural enhancer to increase transdermal permeation of the drug from the matrix system across rat epidermis.Materials and Methods: The chemical characterization of patchouli oil was done by gas chromatography-mass spectrometry. Transdermal patches of indomethacin were formulated after studying the drug-excipient compatibility studies by differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR). The transdermal patches were evaluated for various physiochemical properties. In-vitro transdermal permeation was carried using modified Keshary-Chein diffusion cell across rat epidermis. FTIR studies of rat epidermis were done to understand the mechanism of the permeation enhancing effect of the oil from the matrix patch.Result: The results of physiochemical parameters of the transdermal patch were found satisfactory. The transdermal flux obtained of the different concentration of patchouli oil tend to increase with increasing concentration of the oil and the maximum transdermal flux of 61.92 ± 0.89 μg/cm2/hr was obtained with formulation F7 (containing 1% w/v of patchouli oil) which is similar to the flux of the formulation F2 containing standard enhancer dimethyl sulphoxide. The skin irritation test did not show any edema and the FTIR data of rat epidermis indicated that patchouli oil enhances transdermal permeation of indomethacin by partial extraction of lipids in the stratum corneum.Conclusion: Thus, the results showed a potential enhancing effect of patchouli oil on the transdermal permeation of the model drug indomethacin and may be used as natural permeation enhancer in transdermal drug delivery systems

An Efficient Light-weight LSB steganography with Deep learning Steganalysis

Active research is going on to securely transmit a secret message or so-called steganography by using data-hiding techniques in digital images. After assessing the state-of-the-art research work, we found, most of the existing solutions are not promising and are ineffective against machine learning-based steganalysis. In this paper, a lightweight steganography scheme is presented through graphical key embedding and obfuscation of data through encryption. By keeping a mindset of industrial applicability, to show the effectiveness of the proposed scheme, we emphasized mainly deep learning-based steganalysis. The proposed steganography algorithm containing two schemes withstands not only statistical pattern recognizers but also machine learning steganalysis through feature extraction using a well-known pre-trained deep learning network Xception. We provided a detailed protocol of the algorithm for different scenarios and implementation details. Furthermore, different performance metrics are also evaluated with statistical and machine learning performance analysis. The results were quite impressive with respect to the state of the arts. We received 2.55% accuracy through statistical steganalysis and machine learning steganalysis gave maximum of 49.93~50% correctly classified instances in good condition.Comment: Accepted pape

Formulation and Evaluation of Transdermal Topical Gel of Ibuprofen

The present research work is based on the formulation and evaluation of topical gel of Ibuprofen where Carbopol 940 is used as the polymer. Gels were prepared by dispersing the polymers  in a mixture of water and glycerol with methyl paraben as the preservative and the varying amount of ibuprofen, being kept under magnetic stirring until the homogeneous dispersion was formed. The dispersion was then neutralized and made viscous by the addition of triethanolamine. The Carbopol gels of Ibuprofen were found to be homogenous with good drug loading. The pH of all the gel formulations was found within the neutral pH range which is compatible with skin. And the viscosity of the formulations was found to be feasible for topical drug delivery. The drug content of the three formulations was found in the range of 87.56% to 90.45% which shows efficient drug loading. Results of In vitro drug release study showed that F5 formulation has better diffusion of drug through egg membrane and hence further permeation studies were carried out through rat epidermis. The compatibility study showed that the major peaks in FTIR spectra of the pure drug were found to be intact in their physical mixture. Hence there is no interaction between drug and Carbopol in their physical mixture. Carbopol can be effectively used as the polymer for topical gel preparation. And F5 formulation containing 0.5 % w/w Carbopol 940 may be effectively used as topical transdermal delivery for Ibuprofen. Keywords: Ibuprofen, Transdermal Gel, Drug release, Compatibility stud

Redox regulation in cancer: A double-edged sword with therapeutic potential

Oxidative stress, implicated in the etiology of cancer, results from an imbalance in the production of reactive oxygen species (ROS) and cell’s own antioxidant defenses. ROS deregulate the redox homeostasis and promote tumor formation by initiating an aberrant induction of signaling networks that cause tumorigenesis. Ultraviolet (UV) exposures, γ-radiation and other environmental carcinogens generate ROS in the cells, which can exert apoptosis in the tumors, thereby killing the malignant cells or induce the progression of the cancer growth by blocking cellular defense system. Cancer stem cells take the advantage of the aberrant redox system and spontaneously proliferate. Oxidative stress and gene-environment interactions play a significant role in the development of breast, prostate, pancreatic and colon cancer. Prolonged lifetime exposure to estrogen is associated with several kinds of DNA damage. Oxidative stress and estrogen receptor-associated proliferative changes are suggested to play important roles in estrogen-induced breast carcinogenesis. BRCA1, a tumor suppressor against hormone responsive cancers such as breast and prostate cancer, plays a significant role in inhibiting ROS and estrogen mediated DNA damage; thereby regulate the redox homeostasis of the cells. Several transcription factors and tumor suppressors are involved during stress response such as Nrf2, NFκB and BRCA1. A promising strategy for targeting redox status of the cells is to use readily available natural substances from vegetables, fruits, herbs and spices. Many of the phytochemicals have already been identified to have chemopreventive potential, capable of intervening in carcinogenesis

Nonlinear optical properties of molecular twins

Three different series of twin nonlinear optic (NLO) molecules were studied, in which the two NLO chromophores are linked by a central flexible polymethylene spacer. The first series, which had two azobenzene chromophores (Azo-twins), was designed to also exhibit liquid crystallinity. Most of the members of this series exhibited a nematic mesophase. The second series had two 4-nitrophenol units as chromphores (PNP-twins), while the third one was based on 4-alkylsulfonyl-4'-alkoxy azobenzene chromophores (Sulfazo-twins). These twin NLO systems exhibited interesting odd-even oscillations in their second harmonic generation (SHG) efficiencies in the powder form. When the spacer had an odd number of methylene groups, they exhibited significantly higher powder SHG efficiency than their even counterparts, with the even ones most often exhibiting no detectable SH signal. Preliminary single crystal X-ray diffraction studies performed on the PNP-twin series showed that while the even members possess a molecular center of symmetry and pack centro-symmetrically, the odd ones do not, leading to the observed alternation. The orientational-disordering dynamics of two of the twin series - the PNP and the Sulfazo-twin series, doped in a poly(methyl methacrylate) matrix, was also studied by monitoring the SH-signal decay in electric field poled samples. Interestingly, the maximum attainable SH signal, χ(2), in the poled samples also showed an odd-even oscillation with the odd ones again exhibiting a higher value of χ(2). The temporal stability of the SHG intensity at 70°C, after the removal of the applied corona, was also studied and the relaxation of the chromophores was found to follow a biexponential decay. The slower relaxation component exhibits a spacer length dependence, which suggests the interplay of two factors in governing the temporal stability in such polymer doped twin systems, one is the conformational discomfort experienced by the spacer in adopting a U-shaped geometry, and the other the electrostatic repulsion when two aligned dipoles lie very close to each other

PROTECTIVE ACTIVITY OF ASPARAGUS RACEMOSUS IN METHOTREXATE-INDUCED LIVER TOXICITY IN WISTAR RATS

Objectives: Various clinically available drugs along with the beneficial action also have drastic side effects due to chronic exposure. In liver, these resulting side effects can be over production of reactive oxygen species, which will further lead to oxidative stress and hepatotoxicity. Therefore, as a preventive measure, the protective role of herbal extracts is being evaluated because of its high success rate and low toxic effects. The primary aim of this study was to evaluate the efficiency of the protective role of Asparagus racemosus is evaluated and studied against methotrexate (MTX)-induced hepatic damage in male Wistar albino rats.Methods: The course of the study was for 14 days. During this experimental study, the animals were categorized into four groups with six rats per group. Group I (positive control) which was treated with normal saline, Group II (negative control) with MTX 20 mg/kg of body weight on 12th day, Group III with A. racemosus 300 mg/kg of body weight + MTX 20 mg/kg on 12th day, and Group IV with A. racemosus 100 mg/kg of body weight + MTX 20 mg/kg on 12th day. On 14th day, the animals were sacrificed, and histopathological as well as antioxidant assays were performed.Results and Conclusion: Assays revealed high lipid peroxidation level and low antioxidant levels in Group II. Meanwhile, in Group III and IV, the levels were restored near to control, which supported the protective role of A. racemosus against MTX-induced hepatic damage. Histopathology evaluation also supported the above-mentioned findings