Neem leaf glycoprotein prophylaxis transduces immune dependent stop signal for tumor angiogenic switch within tumor microenvironment

Effects of natural products on angiogenesis in melanoma

Melanoma is the most aggressive form of skin cancer and originates from genetic mutations in melanocytes. The disease is multifactorial, but its main cause is overexposure to UV radiation. Currently, available chemotherapy expresses little to no results, which may justify the extensive use of natural products to treat this cancer. In this study, we reviewed the inhibition of melanoma angiogenesis by natural products and its potential mechanisms using literature from PubMed, EMBASE, Web of Science, Ovid, ScienceDirect and China National Knowledge Infrastructure databases. According to summarizes 27 natural products including alkaloids, polyphenols, terpenoids, flavonoids, and steroids that effectively inhibit angiogenesis in melanoma. In addition to these there are 15 crude extracts that can be used as promising agents to inhibit angiogenesis, but their core components still deserve further investigation. There are current studies on melanoma angiogenesis involving oxidative stress, immune-inflammatory response, cell proliferation and migration and capillary formation. The above natural products can be involved in melanoma angiogenesis through core targets such as VE-cadherin, COX-2, iNOS, VEGF, bFGF, FGF2,MMP2,MMP9,IL-1β,IL-6 play a role in inhibiting melanoma angiogenesis. Effective excavation of natural products can not only clarify the mechanism of drug action and key targets, but also help to promote the preclinical research of natural products for melanoma treatment and further promote the development of new clinical drugs, which will bring the gospel to the vast number of patients who are deeply afflicted by melanoma.

Neem Leaf Glycoprotein Disrupts Exhausted CD8+ T-Cell-Mediated Cancer Stem Cell Aggression

Targeting exhausted CD8+ T-cell (TEX)-induced aggravated cancer stem cells (CSC) holds immense therapeutic potential. In this regard, immunomodulation via Neem Leaf Glycoprotein (NLGP), a plant-derived glycoprotein immunomodulator is explored. Since former reports have proven immune dependent-tumor restriction of NLGP across multiple tumor models, we hypothesized that NLGP might reprogram and rectify TEX to target CSCs successfully. In this study, we report that NLGP's therapeutic administration significantly reduced TEX-associated CSC virulence in in vivo B16-F10 melanoma tumor model. A similar trend was observed in in vitro generated TEX and B16-F10/MCF7 coculture setups. NLGP rewired CSCs by downregulating clonogenicity, multidrug resistance phenotypes and PDL1, OCT4, and SOX2 expression. Cell cycle analysis revealed that NLGP educated-TEX efficiently pushed CSCs out of quiescent phase (G0G1) into synthesis phase (S), supported by hyper-phosphorylation of G0G1-S transitory cyclins and Rb proteins. This rendered quiescent CSCs susceptible to S-phase-targeting chemotherapeutic drugs like 5-fluorouracil (5FU). Consequently, combinatorial treatment of NLGP and 5FU brought optimal CSC-targeting efficiency with an increase in apoptotic bodies and proapoptotic BID expression. Notably a strong nephron-protective effect of NLGP was also observed, which prevented 5FU-associated toxicity. Furthermore, Dectin-1-mediated NLGP uptake and subsequent alteration of Notch1 and mTOR axis were deciphered as the involved signaling network. This observation unveiled Dectin-1 as a potent immunotherapeutic drug target to counter T-cell exhaustion. Cumulatively, NLGP immunotherapy alleviated exhausted CD8+ T-cell-induced CSC aggravation. Implications: Our study recommends that NLGP immunotherapy can be utilized to counter ramifications of T-cell exhaustion and to target therapy elusive aggressive CSCs without evoking toxicity.

Pericytes: jack-of-all-trades in cancer-related inflammation

Pericytes, recognized as mural cells, have long been described as components involved in blood vessel formation, playing a mere supporting role for endothelial cells (ECs). Emerging evidence strongly suggests their multifaceted roles in tissues and organs. Indeed, pericytes exhibit a remarkable ability to anticipate endothelial cell behavior and adapt their functions based on the specific cells they interact with. Pericytes can be activated by pro-inflammatory stimuli and crosstalk with immune cells, actively participating in their transmigration into blood vessels. Moreover, they can influence the immune response, often sustaining an immunosuppressive phenotype in most of the cancer types studied. In this review, we concentrate on the intricate crosstalk between pericytes and immune cells in cancer, highlighting the primary evidence regarding pericyte involvement in primary tumor mass dynamics, their contributions to tumor reprogramming for invasion and migration of malignant cells, and their role in the formation of pre-metastatic niches. Finally, we explored recent and emerging pharmacological approaches aimed at vascular normalization, including novel strategies to enhance the efficacy of immunotherapy through combined use with anti-angiogenic drugs.

Anticoagulation activity of sulfated carboxymethyl cellulose/Azadirachta indica leaf powder-based bio-composite

Polymeric bio-composites synthesized via a green approach using natural herbs have fascinating anticoagulant activity due to their eco-friendly and non-toxic behavior towards various physical and chemical actions. Herein, we introduce a simple and eco-friendly approach for the fabrication of a new hybrid type of bio-composite based on sulfated carboxymethyl cellulose (S-CMC) and Azadirachta indica leaf powder (S-CMC/NLP). First, a non-toxic sulfating agent called N(SO3Na)3 was used to modify carboxymethyl cellulose into S-CMC. With an ion exchange capacity of 0.25 meq. g-1, the level of sulfation (%) of S-CMC (modified polysaccharide) was measured to be 12.01%. Three types of S-CMC/NLP bio-composites were developed by varying the concentration of NLP. FE-SEM, EDX, and XRD were used to characterize the structural features of S-CMC/NLP bio-composites. FTIR spectroscopy indicated that the S-CMC/NLP bio-composite possesses COO-, -OH and SO3- groups, suggesting the structural similarity to heparin. In addition, the anticoagulant effect of the S-CMC/NLP bio-composite was investigated using PT and APTT assays. The APTT investigation confirmed that following the intrinsic pathway of the coagulation system, 2-NLP/S-CMC bio-composite dose-dependently (0.045-0.28 mg mL-1) prolonged the time of blood coagulation compared to control (pure plasma). The S-CMC/NLP bio-composite showed its potential as a new, safe, and effective candidate for anticoagulant activity.

The immunomodulatory impact of naturally derived neem leaf glycoprotein on the initiation progression model of 4NQO induced murine oral carcinogenesis: a preclinical study

Introduction

Murine tumor growth restriction by neem leaf glycoprotein (NLGP) was established in various transplanted models of murine sarcoma, melanoma and carcinoma. However, the role of NLGP in the sequential carcinogenic steps has not been explored. Thus, tongue carcinogenesis in Swiss mice was induced by 4-nitroquinoline-1-oxide (4NQO), which has close resemblance to human carcinogenesis process. Interventional role of NLGP in initiation-promotion protocol established during 4NQO mediated tongue carcinogenesis in relation to systemic immune alteration and epithelial-mesenchymal transition (EMT) is investigated.

Methods

4NQO was painted on tongue of Swiss mice every third day at a dose of 25µl of 5mg/ml stock solution. After five consecutive treatment with 4NQO (starting Day7), one group of mice was treated with NLGP (s.c., 25µg/mice/week), keeping a group as PBS control. Mice were sacrificed in different time-intervals to harvest tongues and studied using histology, immunohistochemistry, flow-cytometry and RT-PCR on different immune cells and EMT markers (e-cadherin, vimentin) to elucidate their phenotypic and secretory status.

Results

Local administration of 4NQO for consecutive 300 days promotes significant alteration in tongue mucosa including erosion in papillae and migration of malignant epithelial cells to the underlying connective tissue stroma with the formation of cell nests (exophytic-hyperkeratosis with mild dysplasia). Therapeutic NLGP treatment delayed pre-neoplastic changes promoting normalization of mucosa by maintaining normal structure. Flow-cytometric evidences suggest that NLGP treatment upregulated CD8+, IFNγ+, granzyme B+, CD11c+ cells in comparison to 4NQO treated mice with a decrease in Ki67+ and CD4+FoxP3+ cells in NLGP treated cohort. RT-PCR demonstrated a marked reduction of MMP9, IL-6, IL-2, CD31 and an upregulation in CCR5 in tongues from 4NQO+NLGP treated mice in comparison to 4NQO treated group. Moreover, 4NQO mediated changes were associated with reduction of e-cadherin and simultaneous up-regulation of vimentin expression in epithelium that was partially reversed by NLGP.

Discussion

Efficacy of NLGP was tested first time in sequential carcinogenesis model and proved effective in delaying the initial progression. NLGP normalizes type 1 immunity including activation of the CD8+T effector functions, reduction of regulatory T cell functions, along with changes in EMT to make the host systemically alert to combat the carcinogenic threat.

Co-Targeting Tumor Angiogenesis and Immunosuppressive Tumor Microenvironment: A Perspective in Ethnopharmacology

Tumor angiogenesis is one of the most important processes of cancer deterioration via nurturing an immunosuppressive tumor environment (TME). Targeting tumor angiogenesis has been widely accepted as a cancer intervention approach, which is also synergistically associated with immune therapy. However, drug resistance is the biggest challenge of anti-angiogenesis therapy, which affects the outcomes of anti-angiogeneic agents, and even combined with immunotherapy. Here, emerging targets and representative candidate molecules from ethnopharmacology (including traditional Chinese medicine, TCM) have been focused, and they have been proved to regulate tumor angiogenesis. Further investigations on derivatives and delivery systems of these molecules will provide a comprehensive landscape in preclinical studies. More importantly, the molecule library of ethnopharmacology meets the viability for targeting angiogenesis and TME simultaneously, which is attributed to the pleiotropy of pro-angiogenic factors (such as VEGF) toward cancer cells, endothelial cells, and immune cells. We primarily shed light on the potentiality of ethnopharmacology against tumor angiogenesis, particularly TCM. More research studies concerning the crosstalk between angiogenesis and TME remodeling from the perspective of botanical medicine are awaited.

NLGP regulates RGS5-TGFβ axis to promote pericyte-dependent vascular normalization during restricted tumor growth

Altered RGS5-associated intracellular pericyte signaling and its abnormal crosstalk with endothelial cells (ECs) result chaotic tumor-vasculature, prevent effective drug delivery, promote immune-evasion and many more to ensure ultimate tumor progression. Moreover, the frequency of lethal-RGS5^high  pericytes within tumor was found to increase with disease progression, which signifies the presence of altered cell death pathway within tumor microenvironment (TME). In this study, we checked whether and how neem leaf glycoprotein (NLGP)-immunotherapy-mediated tumor growth restriction is associated with modification of pericytes' signaling, functions and its interaction with ECs. Analysis of pericytes isolated from tumors of NLGP treated mice suggested that NLGP treatment promotes apoptosis of NG2⁺ RGS5^high -fuctionally altered pericytes by downregulating intra-tumoral TGFβ, along with maintenance of more matured RGS5^neg  pericytes. NLGP-mediated inhibition of TGFβ within TME rescues binding of RGS5 with Gαi and thereby termination of PI3K-AKT mediated survival signaling by downregulating Bcl2 and initiating pJNK mediated apoptosis. Limited availability of TGFβ also prevents complex-formation between RGS5 and Smad2 and rapid RGS5 nuclear translocation to mitigate alternate immunoregulatory functions of RGS5^high  tumor-pericytes. We also observed binding of Ang1 from pericytes with Tie2 on ECs in NLGP-treated tumor, which support re-association of pericytes with endothelium and subsequent vessel stabilization. Furthermore, NLGP-therapy- associated RGS5 deficiency relieved CD4⁺  and CD8⁺ T cells from anergy by regulating 'alternate-APC-like' immunomodulatory characters of tumor-pericytes. Taken together, present study described the mechanisms of NLGP's effectiveness in normalizing tumor-vasculature by chiefly modulating pericyte-biology and EC-pericyte interactions in tumor-host to further strengthen its translational potential as single modality treatment.

Emerging role of natural products in cancer immunotherapy

Cancer immunotherapy has become a new generation of anti-tumor treatment, but its indications still focus on several types of tumors that are sensitive to the immune system. Therefore, effective strategies that can expand its indications and enhance its efficiency become the key element for the further development of cancer immunotherapy. Natural products are reported to have this effect on cancer immunotherapy, including cancer vaccines, immune-check points inhibitors, and adoptive immune-cells therapy. And the mechanism of that is mainly attributed to the remodeling of the tumor-immunosuppressive microenvironment, which is the key factor that assists tumor to avoid the recognition and attack from immune system and cancer immunotherapy. Therefore, this review summarizes and concludes the natural products that reportedly improve cancer immunotherapy and investigates the mechanism. And we found that saponins, polysaccharides, and flavonoids are mainly three categories of natural products, which reflected significant effects combined with cancer immunotherapy through reversing the tumor-immunosuppressive microenvironment. Besides, this review also collected the studies about nano-technology used to improve the disadvantages of natural products. All of these studies showed the great potential of natural products in cancer immunotherapy.

RGS5-TGFβ-Smad2/3 axis switches pro- to anti-apoptotic signaling in tumor-residing pericytes, assisting tumor growth

Regulator-of-G-protein-signaling-5 (RGS5), a pro-apoptotic/anti-proliferative protein, is a signature molecule of tumor-associated pericytes, highly expressed in several cancers, and is associated with tumor growth and poor prognosis. Surprisingly, despite the negative influence of intrinsic RGS5 expression on pericyte survival, RGS5^highpericytes accumulate in progressively growing tumors. However, responsible factor(s) and altered-pathway(s) are yet to report. RGS5 binds with Gαi/q and promotes pericyte apoptosis in vitro, subsequently blocking GPCR-downstream PI3K-AKT signaling leading to Bcl2 downregulation and promotion of PUMA-p53-Bax-mediated mitochondrial damage. However, within tumor microenvironment (TME), TGFβ appeared to limit the cytocidal action of RGS5 in tumor-residing RGS5^highpericytes. We observed that in the presence of high RGS5 concentrations, TGFβ-TGFβR interactions in the tumor-associated pericytes lead to the promotion of pSmad2-RGS5 binding and nuclear trafficking of RGS5, which coordinately suppressed RGS5-Gαi/q and pSmad2/3-Smad4 pairing. The RGS5-TGFβ-pSmad2 axis thus mitigates both RGS5- and TGFβ-dependent cellular apoptosis, resulting in sustained pericyte survival/expansion within the TME by rescuing PI3K-AKT signaling and preventing mitochondrial damage and caspase activation. This study reports a novel mechanism by which TGFβ fortifies and promotes survival of tumor pericytes by switching pro- to anti-apoptotic RGS5 signaling in TME. Understanding this altered RGS5 signaling might prove beneficial in designing future cancer therapy.

The value of the tumour-stroma ratio for predicting neoadjuvant chemoradiotherapy response in locally advanced rectal cancer: a case control study

BACKGROUND

The tumour-stroma ratio (TSR) is recognized as a practical prognostic factor in colorectal cancer. However, TSR assessment generally utilizes surgical specimens. This study aims to investigate whether the TSR evaluated from preoperative biopsy specimens by a semi-automatic quantification method can predict the response after neoadjuvant chemoradiotherapy (nCRT) of patients with locally advanced rectal cancer (LARC).

METHODS

A total of 248 consecutive patients diagnosed with LARC and treated with nCRT followed by resection were included. Haematoxylin and eosin (HE)-stained sections of biopsy specimens were collected, and the TSR was evaluated by a semi-automatic quantification method and was divided into three categories, using the cut-offs determined in the whole cohort to balance the proportion of patients in each category. The response to nCRT was evaluated on the primary tumour resection specimen by an expert pathologist using the four-tier tumour regression grade (TRG) system.

RESULTS

The TSR can discriminate patients that are major-responders (TRG 0-1) from patients that are non-responders (TRG 2-3). Patients were divided into stroma-low (33.5%), stroma-intermediate (33.9%), and stroma-high (32.7%) groups using 56.3 and 72.8% as the cutoffs. In the stroma-low group, 58 (69.9%) patients were major-responders, and only 39 (48.1%) patients were considered major-responders in the stroma-high group (P = 0.018). Multivariate analysis showed that the TSR was the only pre-treatment predictor of response to nCRT (adjusted odds ratio 0.40, 95% confidence interval 0.21-0.76, P = 0.002).

CONCLUSION

An elevated TSR in preoperative biopsy specimens is an independent predictor of nCRT response in LARC. This semi-automatic quantified TSR could be easily translated into routine pathologic assessment due to its reproducibility and reliability.

Exploring the role of Azadirachta indica (neem) and its active compounds in the regulation of biological pathways: an update on molecular approach

In ethnomedicine, plant parts and compounds are used traditionally to treat different diseases. Neem (Azadirachta indica A. Juss) is the most versatile and useful medicinal plant ever found. Its every part is rich in bioactive compounds, which have traditionally been used to treat different ailments including infectious diseases. Bioactive compounds such as nimbolide, azarirachtin, and gedunin of neem are reported to have a tremendous ability to regulate numerous biological processes in vitro and in vivo. The present review article aims to explore the importance of neem extracts and bioactive compounds in the regulation of different biological pathways. We have reviewed research articles up to March 2020 on the role of neem in antioxidant, anti-inflammatory, antiangiogenic, immunomodulatory, and apoptotic activities. Studies on the concerned fields demonstrate that the bioactive compounds and extracts of neem have a regulatory effect on several biological mechanisms. It has been unveiled that extensive research is carried out on limonoids such as nimbolide and azarirachtin. It is evidenced by different studies that neem extracts are the potential to scavenge free radicals and reduce ROS-mediated damage to cells. Neem can be used to normalize lipid peroxidation and minimize ROS-mediated cell death. Besides, neem extracts can significantly reduce the release of proinflammatory cytokines and elevate the count of CD4 + and CD8 + T-cells. This review indicates the pivotal roles of A. indica in the regulation of different biological pathways. However, future investigations on other bioactive compounds of neem may reveal different therapeutic potentials.

Neem leaf glycoprotein salvages T cell functions from Myeloid-derived suppressor cells-suppression by altering IL-10/STAT3 axis in melanoma tumor microenvironment

Myeloid-derived suppressor cells (MDSCs) suppress antitumor immune functions. We have observed that an immunomodulator, neem leaf glycoprotein (NLGP), inhibits tumor-resident MDSCs and enhances antitumor CD8+ T cell immunity. NLGP inhibits the number as well as functions of tumor-resident MDSCs (Gr1±CD11b±) and enhances antitumor CD8± T cell immunity by downregulating arginase 1 and inducible nitric oxide synthase production in MDSCs. Accordingly, decreased T cell anergy and helper to regulatory T cell conversion have been observed in the presence of NLGP, which ultimately augments T cell functions. Mechanistically, NLGP-mediated rectification of T cell suppressive functions of MDSCs was primarily associated with downregulation of the interleukin (IL)-10/signal transducer and activator of transcription 3 (STAT3) signaling axis within the tumor microenvironment, as confirmed by knockdown of STAT3 (by STAT3-siRNA) and using IL-10-/- mice. Thus, NLGP-mediated suppression of MDSC functions in tumor hosts is appeared to be another associated effective mechanism for the eradication of murine melanoma by NLGP.

Neem leaf glycoprotein reverses tumor-induced and age-associated thymic involution to maintain peripheral CD8+ T cell pool

Aim: As tumor causes atrophy in the thymus to target effector-T cells, this study is aimed to decipher the efficacy of neem leaf glycoprotein (NLGP) in tumor- and age-associated thymic atrophy. Materials & methods: Different thymus parameters were studied using flow cytometry, reverse transcriptase PCR and immunocyto-/histochemistry in murine melanoma and sarcoma models. Results: Longitudinal NLGP therapy in tumor hosts show tumor-reduction along with significant normalization of thymic alterations. NLGP downregulates intrathymic IL-10, which eventually promotes Notch1 to rescue blockade in CD25⁺CD44⁺c-Kit⁺DN2 to CD25⁺CD44^-c-Kit^-DN3 transition in T cell maturation and suppress Ikaros/IRF8/Pu.1 to prevent DN2-T to DC differentiation in tumor hosts. The CD5^intTCRαβ^high DP3 population was also increased to endorse CD8⁺ T cell generation. Conclusion: NLGP rescues tumor-induced altered thymic events to generate more effector T cells to restrain tumor.

NLGP Attenuates Murine Melanoma and Carcinoma Metastasis by Modulating Cytotoxic CD8+ T Cells

Neem leaf glycoprotein (NLGP), a natural immunomodulator, attenuates murine carcinoma and melanoma metastasis, independent of primary tumor growth and alterations in basic cellular properties (cell proliferation, cytokine secretion, etc.). Colonization event of invasion–metastasis cascade was primarily inhibited by NLGP, with no effect on metastasis-related invasion, migration, and extravasation. High infiltration of interferon γ (IFN-γ)–secreting cytotoxic CD8⁺ T cells [CD44⁺, CD69⁺, GranB⁺, IFN-γ⁺, and interleukin 2⁺] was documented in the metastatic site of NLGP-treated mice. Systemic CD8⁺ T cell depletion abolished NLGP-mediated metastasis inhibition and reappeared upon adoptive transfer of NLGP-activated CD8⁺ T cells. Interferon γ-secreting from CD8⁺ T cells inhibit the expression of angiogenesis regulatory vascular endothelial growth factor and transforming growth factor β and have an impact on the prevention of colonization. Neem leaf glycoprotein modulates dendritic cells (DCs) for proper antigen presentation by its DC surface binding and upregulation of MHC-I/II, CD86, and CCR7. Neem leaf glycoprotein–treated DCs specifically imprint CXCR3 and CCR4 homing receptors on activated CD8⁺ T cells, which helps to infiltrate into metastatic sites to restrain colonization. Such NLGP's effect on DCs is translation dependent and transcription independent. Studies using ovalbumin, OVA_257−264, and crude B16F10 antigen indicate MHC-I upregulation depends on the quantity of proteasome degradable peptide and only stimulates CD8⁺ T cells in the presence of antigen. Overall data suggest NLGP inhibits metastasis, in conjunction with tumor growth restriction, and thus might appear as a promising next-generation cancer immunotherapeutic.

Neem Leaf Glycoprotein Restrains VEGF Production by Direct Modulation of HIF1α-Linked Upstream and Downstream Cascades

Neem Leaf Glycoprotein (NLGP) is a natural immunomodulator, have shown sustained tumor growth restriction as well as angiogenic normalization chiefly by activating CD8⁺ T cells. Here, we have investigated the direct role of NLGP as a regulator of tumor microenvironmental hypoxia and associated vascular endothelial growth factor (VEGF) production. We observed a significant reduction in VEGF level in both in vivo murine tumor and in vitro cancer cells (B16Mel, LLC) and macrophages after NLGP treatment. Interestingly, NLGP mediated VEGF downregulation in tumor cells or macrophages within hypoxic chamber was found at an early 4 h and again at late 24 h in mRNA level. Our data suggested that NLGP prevented hypoxia-induced strong binding of HIF1α with its co-factors, CBP/p300 and Sp3, but not with Sp1, which eventually limit the binding of HIF1α-transcriptional complex to hypoxia responsive element of VEGF promoter and results in restricted early VEGF transcription. On the otherhand, suppressed phosphorylation of Stat3 by NLGP results reduction of HIF1α at 24 h of hypoxia that further support sustained VEGF down-regulation. However, NLGP fails to regulate VHL activity as observed by both in vivo and in vitro studies. Therefore, this study for the first time reveals a mechanistic insight of NLGP mediated inhibition of angiogenesis by suppressing VEGF, which might help in vascular normalization to influence better drug delivery.

An Overview on the Anticancer Activity of Azadirachta indica (Neem) in Gynecological Cancers

In recent years, a wide range of studies have pointed out the importance of nutraceuticals as reservoirs of therapeutic compounds for several diseases, including cancer. This study is centered on the role of some nutraceuticals as anticancer agents and on their efficiency in the oncological gynecological field. Gynecological cancers include cervical, ovarian, and breast neoplasia and these are the major causes of morbidity and mortality in the female population. Cervical neoplasia affects sexually active women aged between 30 and 40 years and is considered the second leading cause of death for women worldwide. Epidemiological studies have shown a strong association of this cancer with human papilloma virus (HPV) infection, independent of any others risk factors. Ovarian cancer represents about 4% of all women’s cancers and breast neoplasia registers 52.8 new cases per 100,000 women annually. Since ancient times, herbal therapies have shown a wide range of beneficial effects and a high potential for safeguarding human health. Azadirachta indica (Neem) is a medicinal plant of Indian origin, a tree with more of 140 isolated compounds and at least 35 biologically active principles that have shown an important influence as tumor suppressors by interfering with the carcinogenesis process. Used for centuries in Asia as a natural remedy for cancer, neem compounds present in bark, leaves, flowers, and seed oil have been shown to possess properties such as chemopreventive capacity, apoptotic activities, immunomodulatory effects, and induction of p53-independent apoptosis. The current study is a systematic literature review based on the anticarcinogenic potential of neem compounds in gynecological cancers.

Use of Nutraceuticals in Angiogenesis-Dependent Disorders

The term of angiogenesis refers to the growth of new vessels from pre-existing capillaries. The phenomenon is necessary for physiological growth, repair and functioning of our organs. When occurring in a not regulated manner, it concurs to pathological conditions as tumors, eye diseases, chronic degenerative disorders. On the contrary insufficient neovascularization or endothelial disfunction accompanies ischemic and metabolic disorders. In both the cases an inflammatory and oxidative condition exists in supporting angiogenesis deregulation and endothelial dysfunction. The use of nutraceuticals with antioxidant and anti-inflammatory activities can be a therapeutic option to maintain an adequate vascularization and endothelial cell proper functioning or to blunt aberrant angiogenesis. A revision of the updated literature reports on nutraceuticals to guide endothelial cell wellness and to restore physiological tissue vascularization is the objective of this paper. The critical aspects as well as lacking data for human use will be explored from a pharmacological perspective.

Neem leaf glycoprotein prevents post-surgical sarcoma recurrence in Swiss mice by differentially regulating cytotoxic T and myeloid-derived suppressor cells

Post-surgical tumor recurrence is a common problem in cancer treatment. In the present study, the role of neem leaf glycoprotein (NLGP), a novel immunomodulator, in prevention of post-surgical recurrence of solid sarcoma was examined. Data suggest that NLGP prevents tumor recurrence after surgical removal of sarcoma in Swiss mice and increases their tumor-free survival time. In NLGP-treated tumor-free mice, increased cytotoxic CD8⁺ T cells and a decreased population of suppressor cells, especially myeloid-derived suppressor cells (MDSCs) was observed. NLGP-treated CD8⁺ T cells showed greater cytotoxicity towards tumor-derived MDSCs and supernatants from the same CD8⁺ T cell culture caused upregulation of FasR and downregulation of cFLIP in MDSCs. To elucidate the role of CD8⁺ T cells, specifically in association with the downregulation in MDSCs, CD8⁺ T cells were depleted in vivo before NLGP immunization in surgically tumor removed mice and tumor recurrence was noted. These mice also exhibited increased MDSCs along with decreased levels of Caspase 3, Caspase 8 and increased cFLIP expression. In conclusion, it can be stated that NLGP, by activating CD8⁺ T cells, down regulates the proportion of MDSCs. Accordingly, suppressive effects of MDSCs on CD8⁺ T cells are minimized and optimum immune surveillance in tumor hosts is maintained to eliminate the residual tumor mass appearing during recurrence.

Tumor promoting role of anti-tumor macrophages in tumor microenvironment

Recent advances in tumor biology demand detailed analysis of the complex interaction of tumor cells with their adjacent microenvironment (tumor stroma) to understand the various mechanisms involved in tumor growth and metastasis. Mononuclear phagocytes or macrophages, a type of innate immune cells, defend the organism against infection and injury. On the otherhand, tumor associated macrophages (TAMs) constitute a significant part of the tumor-infiltrating immune cells, have been linked to the growth, angiogenesis, and metastasis of a variety of cancers, most likely through polarization of TAMs to the M2 (alternative) phenotype. Clinical and experimental evidences have shown that cancer tissues with high infiltration of TAMs are associated with poor patient prognosis and resistance to therapies, thus, targeting of TAMs in tumors is considered as a promising immunotherapeutic strategy. Depletion of M2 TAMs or 're-education' of them as anti-tumor effectors might contribute significantly to the search of new modalities in anti-cancer treatments. Basic questions on the factors responsible for homing of macrophages in tumors, mechanism of conversion of M1 to M2 TAMs, their functionality and, finally, the possible ways to target M2 TAMs are discussed.

Dexamethasone provoked mitochondrial perturbations in thymus: Possible role of N-acetylglucosamine in restoration of mitochondrial function

Thymus mitochondria play a crucial role in immune function. This study identifies the novel protective role of N-Acetylglucosamine (NAG) in dexamethasone (DEX) induced mitochondrial perturbations in mice thymus. Mice were induced with DEX (5mg/kg) and treated with NAG i.p. (266μg/kg, 400μg/kg and 800μg/kg) for 14 days, Withanolide A (800μg/kg) has been used as positive control. Dose dependent treatment of NAG against DEX significantly restored the mitochondrial enzyme levels (ICDH, KDH, SDH and MDH) and elevated the mitochondrial glutathione antioxidants defense (GSH, SOD, GPX and GST) thus improving the ATP status which was confirmed by ultrastructural alterations in mitochondria and nucleus using TEM studies. Further histopathological studies also revealed that NAG attenuate DEX induced thymotoxicity. Finally, the study concludes that dose dependent treatment of NAG supports a potential role in preventing DEX induced thymotoxicity and NAG acts as a beneficial pharmacological intervention in the DEX induced thymic repercussions.

An overlooked tumor promoting immunoregulation by non-hematopoietic stromal cells

Multidirectional complex communication between tumor-residing hematopoietic and non-hematopoietic stromal cells (NHSCs) decisively regulates cancer development, progression and therapeutic responses. HSCs predominantly participate in the immune regulations, while, NHSCs, provide parenchymal support or serve as a conduit for other cells or support angiogenesis. However, recent reports suggest NHSCs can additionally participate in ongoing tumor promoting immune reactions within tumor-microenvironment (TME). In this review, based on the state-of-art knowledge and accumulated evidence by us, we discuss the role of quite a few NHSCs in tumor from immunological perspectives. Understanding such consequence of NHSCs will surely pave the way in crafting effective cancer management.

Absence of CD4(+) T cell help generates corrupt CD8(+) effector T cells in sarcoma-bearing Swiss mice treated with NLGP vaccine

One of the prime objectives of cancer immunology and immunotherapy is to study the issues related to rescue and/or maintenance of the optimum effector CD8(+) T cell functions by minimizing tumor-induced negative factors. In this regard the influence of host intrinsic CD4(+) helper T cells towards generation and maintenance of CD8(+) effector T cells appears controversial in different experimental settings. Therefore, the present study was aimed to re-analyze the influence of CD4(+) helper T cells towards effector T cells during neem leaf glycoprotein (NLGP)-vaccine-mediated tumor growth restriction. CD4 depletion (mAb; Clone GK1.5) surprisingly resulted in significant increase in CD8(+) T cells in different immune organs from NLGP-treated sarcoma-bearing mice. However, such CD8 surge could not restrict the sarcoma growth in NLGP-treated CD4-depleted mice. Furthermore, CD4 depletion in early phase hinders CD8(+) T cell activation and terminal differentiation by targeting crucial transcription factor Runx3. CD4 depletion decreases accumulation of CD8α(+) dendritic cells within tumor draining lymph node, hampers antigen cross priming and CD86-CD28 interactions for optimum CD8(+) T cell functions. In order to search the mechanism of CD4(+) T cell help on NLGP-mediated CD8 effector functions, the role of CD4(+) helper T cell-derived IL-2 on optimization of CD8 functions was found using STAT5 signaling, but complete response requires physical contact of CD4(+) helper T cells with its CD8 counterpart. In conclusion, it was found that CD4(+) T cell help is not required to generate CD8(+) T cells but was found to be an integral phenomenon in maintenance of its anti-tumor functions even in NLGP-vaccine-mediated sarcoma growth restriction.

Neem leaf glycoprotein promotes dual generation of central and effector memory CD8(+) T cells against sarcoma antigen vaccine to induce protective anti-tumor immunity

We have previously shown that Neem Leaf Glycoprotein (NLGP) mediates sustained tumor protection by activating host immune response. Now we report that adjuvant help from NLGP predominantly generates CD44(+)CD62L(high)CCR7(high) central memory (TCM; in lymph node) and CD44(+)CD62L(low)CCR7(low) effector memory (TEM; in spleen) CD8(+) T cells of Swiss mice after vaccination with sarcoma antigen (SarAg). Generated TCM and TEM participated either to replenish memory cell pool for sustained disease free states or in rapid tumor eradication respectively. TCM generated after SarAg+NLGP vaccination underwent significant proliferation and IL-2 secretion following SarAg re-stimulation. Furthermore, SarAg+NLGP vaccination helps in greater survival of the memory precursor effector cells at the peak of the effector response and their maintenance as mature memory cells, in comparison to single modality treatment. Such response is corroborated with the reduced phosphorylation of FOXO in the cytosol and increased KLF2 in the nucleus associated with enhanced CD62L, CCR7 expression of lymph node-resident CD8(+) T cells. However, spleen-resident CD8(+) T memory cells show superior efficacy for immediate memory-to-effector cell conversion. The data support in all aspects that SarAg+NLGP demonstrate superiority than SarAg vaccination alone that benefits the host by rapid effector functions whenever required, whereas, central-memory cells are thought to replenish the memory cell pool for ultimate sustained disease free survival till 60 days following post-vaccination tumor inoculation.

Therapeutic anti-NLGP monoclonal antibody for carcinoembryonic antigen expressing tumors is nontoxic to Swiss and BALB/c mice

A murine monoclonal antibody (mAb), 1C8 was developed against a novel glycoprotein NLGP and its unique property to recognize carcinoembryonic antigen (CEA) was reported. Utilizing this CEA recognizing property, 1C8 is successful to restrict the growth of CEA(+) murine and human cancers both in vitro and in vivo. Here, we have thoroughly evaluated the toxicity profile of this mAb 1C8 on different physiological systems of both tumor-free and tumor-bearing Swiss and BALB/c mice. Effective concentration (25 μg/mice) of 1C8 caused no behavioral changes in animals and no death was recorded. Moreover, little increase in the body and organ weights in all mice groups was noted. MAb 1C8 showed no adverse effect on the hematological system, but little hematostimulation was noticed, as evidenced by increased hemoglobin content, leukocyte count and lymphocyte numbers. Liver enzymes like alkaline phosphatase, SGOT, SGPT and nephrological products like urea and creatinine assessment confirmed no abnormalities in both hepatic and renal functions. Number of T cells, B cells, NK cells, macrophages and dendritic cells was upregulated in vivo by mAb treatment with significant downregulation of regulatory T cells. During this treatment serum levels of type 1 cytokines were upregulated over type 2 cytokines. This mAb 1C8 also did not induce any significant increase in antibody titer following treatment. Accumulated evidences from Swiss and BALB/c mice strongly suggest that this mAb 1C8 is completely safe, thus, can be recommended for further clinical trial for the therapy of CEA(+) tumors.

Exogenous natural glycoprotein multiple mechanisms of anti-tumor activity

Natural glycoproteins can induce apoptosis of tumor cells and exert anti-tumor activity by immunomodulatory functions, cytotoxic and anti-inflammation effects, and inhibition of endothelial growth factor. Given their prospects as novel agents, sources of natural antitumor glycoproteins have attracted attention and new research directions in glycoprotein biology are gradually shifting to the direction of cancer treatment and prevention of neoplastic disease. In this review, we summarize the latest findings with regard to the tumor suppressor signature of glycoproteins and underlying regulatory mechanisms.