Apoptosis induction by Epican Forte in HTLV-1 positive and negative malignant T-cells

Montivipera bornmuelleri venom selectively exhibits high cytotoxic effects on keratinocytes cancer cell lines

CONTEXT

The Viperidae family venom is a rich source of bioactive compounds such as many proteases, which cause tissue necrosis and affect mostly the vascular system. However, the venom exhibits therapeutic potentials and has contributed to the development of some medical drugs. Specifically, the Montivipera bornmuelleri venom has shown to exhibit antibacterial, pro-inflammatory and antifungal activities.

OBJECTIVE

This work evaluates the cytotoxic effect of the M. bornmuelleri venom on human-derived keratinocytes including the non-tumorigenic HaCaT, the benign A5 and the low-grade malignant II4 cells.

MATERIALS AND METHODS

The toxicity of different venom concentrations (0.9, 1.87, 3.75, 7.5, 15, 30 and 60μg/mL) and their effect on the viability of the cells lines were assessed using the Lactate Dehydrogenase (LDH) activity and the Trypan blue tests after 24h of incubation.

RESULTS

The venom was able to reduce the viability of all cell lines in a dose dependent manner with the HaCat cells being the least affected. For example, the 60μg/mL dose induced a more significant decrease the viability of A5 (44%) and II4 (21.33%) keratinocytes as compared to HaCaT cells (70.63%). Also, this venom showed a higher cytotoxic activity on the A5 (52.45%) and II4 (98.67%) cells as compared to HaCaT cells (30.14%) with an IC₅₀ estimated at 10μg/mL on II4 and at 60μg/mL on benign A5.

DISCUSSION AND CONCLUSION

Those differential cytotoxic effects of the M. bornmuelleri venom pave the road for more advanced studies which might unravel the potential anticancer effects of this venom.

pecific nutrient combination effects on tax, NF- κB and MMP-9 in human T-cell lymphotropic virus -1 positive malignant T-lymphocytes

BACKGROUND

Adult T-cell Leukemia (ATL) is a disease with no known cure. The disease manifests itself as an aggressive proliferation of CD4+ cells with the human T-cell Lymphotropic virus type 1 (HTLV-1). The leukemogenesis of the virus is mainly attributed to the viral oncoprotein. Tax activates the Nuclear Factor kappa B (NF-κB) which stimulates the activity and expression of the matrix metalloproteinase-9 (MMP-9). The objective of this study was to investigate the efficacy of a specific nutrient synergy (SNS) on proliferation, Tax expression, NF-κB levels as well as on MMP-9 activity and expression both at the transcriptional and translational levels in two HTLV-1 positive cell lines, HuT-102 and C91-PL at 48h and 96h of incubation. Cytotoxicity of Epigallocatechin-3-gallate (EGCG) was assayed using CytoTox 96 Non-radioactive and proliferation was measured using Cell Titer96TM Nonradioactive Cell Proliferation kit (MTT- based assay). Enzyme linked immunosorbant assay (ELISA) and electrophoretic mobility shift assay (EMSA) were used to assess the effect of SNS on NF-κB mobility. Zymography was used to determine the effects of SNS on the activity and secretion of MMP-9. The expression of MMP-9 was done using RT-PCR at the translational level and Immunoblotting at the transcriptional level.

RESULTS

A significant inhibition of proliferation was seen in both cell lines starting at a concentration of 200μg/ml and in a dose dependent manner. SNS induced a dose dependent decrease in Tax expression, which was paralleled by a down-regulation of the nuclearization of NF-κB. This culminated in the inhibition of the activity of MMP-9 and their expression both at the transcriptional and translational levels.

CONCLUSIONS

The results of this study indicate that a specific nutrient synergy targeted multiple levels pertinent to the progression of ATL. Its activity was mediated through the NF-κB pathway, and hence has the potential to be integrated in the treatment of this disease as a natural potent anticancer agent.

Effects of nutrients on matrix metalloproteinases in human T-lymphotropic virus type 1 positive and negative malignant T-lymphocytes

Experimental and clinical studies have revealed the effectiveness of a specific nutrient synergy (SNS) mixture composed of ascorbic acid (AA), lysine, proline, arginine, epigallocatechin gallate (EGCG) and other micronutrients in targeting crucial physiological mechanisms involved in cancer progression and metastasis. HTLV-1 causes adult T-cell leukemia (ATL). The spread and metastases of ATL as well as other tumors has been associated with matrix metalloproteinases, especially the gelatinases MMP-2 and MMP-9. The objective of this study was to investigate whether SNS, AA and EGCG affects the gelatinolytic activity of MMP-2 and its transcriptional and translational levels in HTLV-1-positive and -negative malignant T-cells. The results indicated that SNS and EGCG caused a dose-dependent decline in the activity, transcription and translation of MMP-2 after treatment with SNS and EGCG, while AA was only able to inhibit the activity at maximum doses tested and to some extent, the protein expression levels of MMP-2, without affecting their transcriptional levels. The highest activity was noted in the case of SNS which is likely to be due to a synergistic effect of the different constituents in the formulation. These results point towards the potential integration of SNS in the anti-invasive treatment of ATL and related diseases.

Cancer chemoprevention by polyphenols and their potential application as nanomedicine

Today cancer is a leading cause of death among the developed countries. Its highly complex nature makes it difficult to understand as it entails multiple cellular physiological systems such as cell signaling and apoptosis. The biggest challenges faced by cancer chemoprevention/chemotherapy is maintaining drug circulation and avoiding multidrug resistance. Overall there is modest evidence regarding the protective effects of nutrients from supplements against a number of cancers. Numerous scientific literatures available advocate the use of polyphenols for chemoprevention. Some groups have also suggested use of combination of nutrients in cancer prevention. However, we have yet to obtain the desired results in the line of cancer chemotherapy research. Nanotechnology can play a pivotal role in cancer treatment and prevention. Moreover, nanoparticles can be modified in various ways to prolong circulation, enhance drug localization, increase drug efficacy, and potentially decrease the chances of multidrug resistance. In this communication, we will cover the use of various polyphenols and nutrients in cancer chemoprevention. The application of nanotechnology in this regard will also be included. In view of available reports on the potential of nanoparticles, we suggest their usage along with different combination of nutrients as cancer chemotherapeutic agents.

A monoclonal antibody directed against a conformational epitope of the HIV-1 trans-activator (Tat) protein neutralizes cross-clade

The identification of a neutralizing mAb against extracellular HIV-1 transactivator of transcription (Tat) is important for the development of an efficient HIV-1 treatment. Tat plays an essential role in HIV-1 pathogenesis, not only for HIV-1 replication but also as an extracellular toxin able to disrupt the immune system. We showed previously that immunization of rabbits with Tat Oyi, a variant cloned from an African woman who did not develop AIDS following HIV-1 infection, raised antibodies able to recognize different Tat variants. We carried out mice immunization with Tat Oyi and selected a mAb named 7G12, which had the capacity to cross-recognize heterologous Tat variants by a common three-dimensional epitope. These results highlighted that Tat variants were able to acquire a structure, in contrast to a number of studies showing Tat as an unfolded protein. mAb 7G12 also had the capacity to neutralize the biological activities of these Tat variants by blocking the cellular uptake of extracellular Tat. This is the first study using Tat Oyi to produce a mAb able to neutralize effectively activities of extracellular Tats from different HIV-1 subtypes. This mAb has an important potential in therapeutic passive immunization and could help HIV-1 infected patients to restore their immunity.

Evaluation of the effects of Quercetin and Kaempherol on the surface of MT-2 cells visualized by atomic force microscopy

This study investigated the anti-viral effects of the polyphenolic compounds Quercetin and Kaempherol on the release of HTLV-1 from the surface of MT-2 cells. Atomic force microscopy (AFM) was used to scan the surface of the MT-2 cells. MT-2 cells were fixed with 100% methanol on round glass lamina or cleaved mica and dried under UV light and laminar flow. The images were captured on a Multimode equipment monitored by a NanoScope IIId controller from Veeco Instruments Inc operated in tapping mode and equipped with phase-imaging hardware. The images demonstrated viral budding structures 131 ± 57 nm in size, indicating profuse viral budding. Interestingly, cell-free viruses and budding structures visualized on the surface of cells were less common when MT-2 was incubated with Quercetin, and no particles were seen on the surface of cells incubated with Kaempherol. In summary, these data indicate that HTLV-1 is budding constantly from the MT-2 cell surface and that polyphenolic compounds were able to reduce this viral release. Biological samples were analyzed with crude cell preparations just after cultivation in the presence of Quercetin and Kaempherol, showing that the AFM technique is a rapid and powerful tool for analysis of antiviral activity of new biological compounds.

The antioxidant and anti-proliferative activity of the Lebanese Olea europaea extract

It is becoming increasingly evident that certain phytochemicals possess cancer chemopreventive properties. In this study, the anti-proliferative activity of plant extracts from olive (Olea europaea L.) leaves was tested on human leukemic cell line (Jurkat). Cytotoxicity of various concentrations of plant extracts was examined and the IC(50) was determined. Olive leaf extracts showed concentration-dependent anti-proliferative effect as determined by the WST-1 proliferation kit and [(3)H]-thymidine incorporation method. To study whether cell death was due to apoptosis, cells were stained with Annexin V-FITC and PI and the expression of important regulatory proteins (Bcl-2, Bax, and p53) involved in apoptosis were examined by Western blot. The antioxidant activity of olive leaves (SC(50) = 0.1 mg dry weight) was studied using the DPPH scavenging method. Present findings suggest that olive leaves extracts exhibit anti-proliferative effect on leukemic cells by inducing apoptosis.

Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

BACKGROUND

Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer.

PURPOSE

The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1)-negative malignant T-lymphocytes.

METHODS

Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α), transforming growth factor- beta1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA) and flow cytometry.

RESULTS

The maximum cytotoxicity recorded after 48-hours treatment with 80 μg/μL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF-β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG(1) phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines.

CONCLUSION

In conclusion, kefir is effective in inhibiting proliferation and inducing apoptosis of HTLV-1-negative malignant T-lymphocytes. Therefore, further in vivo investigation is highly recommended.

Micronutrient synergy--a new tool in effective control of metastasis and other key mechanisms of cancer

Consumption of a plant-based diet has been associated with prevention of the development and progression of cancer. We have developed strategies to inhibit cancer development and its spread by targeting common mechanisms used by all types of cancer cells that decrease stability and integrity of connective tissue. Strengthening of collagen and connective tissue can be achieved naturally through the synergistic effects of selected nutrients, such as lysine, proline, ascorbic acid and green tea extract (NM). This micronutrient mixture has exhibited a potent anticancer activity in vivo and in vitro in a few dozen cancer cell lines. Its anti-cancer effects include inhibition of metastasis, tumor growth, matrix metalloproteinase (MMP) secretion, invasion, angiogenesis, and cell growth as well as induction of apoptosis. Many cancers are often diagnosed at later stages, when metastasis has occurred, which standard treatment has been unable to control. Our studies on NM effects on hepatic and pulmonary metastasis demonstrated profound, significant suppression of metastasis in a murine model. Evaluation of effects of NM on xenografts in murine models demonstrated significant reduction in tumor size and tumor burden in all human cancer cell lines tested. In vitro studies demonstrated that NM was very effective in inhibition of cell proliferation (by MTT assay), MMP secretion (by gelatinase zymography), cell invasion (through Matrigel), cell migration (by scratch test), induction of apoptosis (by live green caspase) and induction of pro-apoptotic genes in many diverse cancer cell lines. Furthermore, in vivo and in vitro studies of effects of individual micronutrients compared to their specific combination demonstrated synergistic effects resulting in improved anticancer potency.

HTLV-1 and apoptosis: role in cellular transformation and recent advances in therapeutic approaches

A universal cellular defense mechanism against viral invasion is the elimination of infected cells through apoptotic cell death. To counteract host defenses many viruses have evolved complex apoptosis evasion strategies. The oncogenic human retrovirus HTLV-1 is the etiological agent of adult-T-cell leukemia/lymphoma (ATLL) and the neurodegenerative disease known as HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The poor prognosis in HTLV-1-induced ATLL is linked to the resistance of neoplastic T cells against conventional therapies and the immuno-compromised state of patients. Nevertheless, several studies have shown that the apoptotic pathway is largely intact and can be reactivated in ATLL tumor cells to induce specific killing. A better understanding of the molecular mechanisms employed by HTLV-1 to counteract cellular death pathways remains an important challenge for future therapies and the treatment of HTLV-1-associated diseases.

Inhibition of cellular invasive parameters in influenza A virus-infected MDCK and Vero cells by a nutrient mixture

Influenza, a long-standing common infection, poses a serious health problem causing significant morbidity and mortality, and imposing substantial economic costs. To date there are no effective antiviral therapies. A unique nutrient mixture (NM), containing lysine, proline, ascorbic acid, green tea extract, N-acetyl cysteine and selenium among other micro nutrients, has been shown to exert a wide range of biochemical and pharmacological effects, among them anti-carcinogenic and anti-atherogenic activity both in vitro and in vivo. In a previous study, NM was found to significantly inhibit influenza virus A associated neuraminidase enzyme as well as production of NP antigen in a dose-dependent manner. Influenza virus A not only infects pulmonary areas, but also manifests in extrapulmonary areas, which require basement membrane disruption by matrix metalloproteinases capable of degrading collagen type IV. This prompted us to study the effect of NM on cellular invasive parameters of virus-infected and non-infected MDCK and Vero cells. NM inhibited extracellular invasive parameters such as MMP-2 and MMP-9 secretion and Matrigel invasion. Results indicated that the relatively non-toxic nutrient mixture tested in this investigation has potential in influenza treatment by not only decreasing viral multiplication in infected cells but also by blocking the enzymatic degradation of the extracellular matrix.

Inhibition of pulmonary metastasis of melanoma b16fo cells in C57BL/6 mice by a nutrient mixture consisting of ascorbic Acid, lysine, proline, arginine, and green tea extract

The authors investigated the effect of a nutrient mixture (NM) on lung metastasis by B16F0 melanoma cells in C57BL/6 female mice. Mice were divided into equal groups (1 to 6) and injected via tail vein with B16F0 cells (groups 1 to 4), B16FO cells pretreated with NM (group 5), or saline (group 6). Groups 1, 3, 4, 5, and 6 were fed the control diet and group 2 the 0.5% NM supplemented diet. Groups 3 and 4 received NM intraperitoneally (IP) and intravenously (IV), respectively. Two weeks later, pulmonary metastatic colonies were counted. Pulmonary colonization was reduced by 63% in mice supplemented with NM diet, by 86% in mice receiving NM by IP and IV injections, and completely inhibited in mice injected with melanoma cells pretreated with NM. These results show that NM is effective in inhibiting the metastasis of B16FO melanoma cells.

In vivo and in vitro antitumor effect of a unique nutrient mixture on lung cancer cell line A-549

The high incidence of lung cancer and ineffective toxic action of current mono and doublet chemotherapy approaches result in poor patient survival. Further, matrix metalloproteinases (MMPs) are implicated in neoplastic invasion and metastasis. Based on this, the authors investigated the effect of a dietary micronutrient mixture (NM) containing lysine, proline, arginine, ascorbic acid, and green tea extract on the tumor growth of human lung carcinoma cell A-549 xenografts in athymic nude mice. Additionally, the authors tested the in vitro antitumor effect of NM on lung carcinoma A-549 cells by measuring cell proliferation by MTT assay, MMP-2 and -9 secretion by gelatinase zymography, and cell invasion through Matrigel. Nutrient supplementation strongly suppressed the growth of tumors without adverse effects in nude mice; tumor weight was reduced by 44% (P = .0001) and tumor burden was reduced by 47% (P < .0001) with supplementation. Zymography demonstrated in vitro secretion of MMP-2 by uninduced human lung carcinoma cells and both MMP-2 and -9 by phorbol 12-mysristate 13-acetate (PMA) (200 ng/mL)-treated cells. NM inhibited the secretion of both MMPs in a dose-dependent fashion, with virtual total inhibition at 500 microg/mL concentration. The invasion of human lung carcinoma cells through Matrigel was significantly reduced at 100 microg/mL (64%) and totally inhibited at 500 microg/mL concentration of NM (P = .01). Suppression of lung tumor growth in nude mice and inhibition of MMP secretion and Matrigel invasion suggest NM may act as an anticancer agent and as such warrants further investigation.