Inonotus obliquus extract induces apoptosis in the human colorectal carcinoma’s HCT-116 cell line

Unveiling the regulatory mechanisms of nodules development and quality formation in Panax notoginseng using multi-omics and MALDI-MSI

INTRODUCTION

Renowned for its role in traditional Chinese medicine, Panax notoginseng exhibits healing properties including bidirectional regulatory effects on hematological system diseases. However, the presence of nodular structures near the top of the main root, known as nail heads, may impact the quality of the plant's valuable roots.

OBJECTIVES

In this paper, we aim to systematically analyze nail heads to identify their potential correlation with P. notoginseng quality. Additionally, we will investigate the molecular mechanisms behind nail head development.

METHODS

Morphological characteristics and anatomical features were analyzed to determine the biological properties of nail heads. Active component analysis and MALDI mass spectrometry imaging (MALDI-MSI) were performed to determine the correlation between nail heads and P. notoginseng quality. Phytohormone quantitation, MALDI-MSI, RNA-seq, and Arabidopsis transformation were conducted to elucidate the mechanisms of nail head formation. Finally, protein-nucleic acid and protein-protein interactions were investigated to construct a transcriptional regulatory network of nodule development and quality formation.

RESULTS

Our analyses have revealed that nail heads originate from an undeveloped lateral root. The content of ginsenosides was found to be positively associated with the amount of nail heads. Ginsenoside Rb1 specifically accumulated in the cortex of nail heads, while IAA, tZR and JAs also showed highest accumulation in the nodule. RNA-seq analysis identified PnIAA14 and PnCYP735A1 as inhibitors of lateral root development. PnMYB31 and PnMYB78 were found to form binary complexes with PnbHLH31 to synergistically regulate the expression of PnIAA14, PnCYP735A1, PnSS, and PnFPS.

CONCLUSION

Our study details the major biological properties of nodular structures in P. notoginseng and outlines their impact on the quality of the herb. It was also determined that PnMYB31- and PnMYB78-PnbHLH31 regulate phytohormones and ginsenosides accumulation, further affecting plant development and quality. This research provides insights for quality evaluation and clinical applications of P. notoginseng.

Inotodiol induces hepatocellular carcinoma apoptosis by activation of MAPK/ERK pathway

Hepatocellular carcinoma(HCC) has a high mortality and morbidity rate and seriously jeopardizes human life. Chemicals and chemotherapeutic agents have been experiencing problems such as side effects and drug resistance in the treatment of HCC, which cannot meet the needs of clinical treatment. Therefore, finding novel low-toxicity and high-efficiency anti-hepatocellular carcinoma drugs and exploring their mechanisms of action have become the current problems to be solved in the treatment of HCC. Several studies have reported anticancer effects of inotodiol. This study focuses on the anticancer effect of inotodiol in HCC cells and its molecular mechanism, aiming to explore its anticancer effect in depth. The CCK8 assay was utilized to assess cell viability, the scratch assay was utilized to detect migration ability, the clone formation assay was utilized to detect clonogenic ability, and flow cytometry was utilized to analyze apoptosis and cell cycle. Animal experiments was utilized to verify the inhibitory effect of inotodiol on HCC. Meanwhile, western blotting was utilized to detect proteins associated with apoptosis, cell cycle and MAPK/ERK pathway. These results showed that inotodiol has the ability to promote apoptosis, as well as inhibit the ability of cell proliferation, migration, and clonogenic ability. The cell cycle was arrested in G1 phase, when the expression of CDK2, CDK4, CDK6 and Cyclin D were inhibited. In addition, inotodiol showed to induce apoptosis, characterized by an increase in Bax expression, a decrease in Bcl-2, Bcl-XL and MCL1 expression, the initiation of cleaved PARP1 and cleaved caspase 3, and inhibition of the MAPK/ERK pathway. Animal studies demonstrated that inotodiol possessed the ability to suppress tumor growth in nude mice models, at the same time, there was no significant impact on the body weight and organs of the mice. In conclusion, the findings presented herein compellingly suggest that inotodiol may serve as a promising candidate for the treatment of hepatocellular carcinoma (HCC).

Biofortification of Mushrooms: A Promising Approach

Mushrooms exhibit a broad spectrum of pharmacological activities and are widely used for medical purposes and in nutrition. Numerous bioactive metabolites are responsible for these activities. Their distribution and biological effects differ depending on the fungal species and their chemical composition. Biofortification is a sustainable process that aims to improve the nutritional profile of food crops, as most of them are low in key nutrients. This review aims to delve into the process of fungal biofortification and review the most commonly used elements and species. Through biofortification, it is possible to combat hidden hunger, which affects as many as 2 billion people worldwide. "Hidden hunger" is a phenomenon in which the organism lacks the minerals and vitamins needed for development, growth, and good overall health. Mushrooms are increasingly being considered for biofortification due to their ability to accumulate various elements (both micro- and macroelements).

Structural characterization of the polysaccharide from the black crystal region of Inonotus obliquus and its effect on AsPC-1 and SW1990 pancreatic cancer cell apoptosis

In this study, one water soluble polysaccharide (IOP1-1) with a weight average molecular weight of 6886 Da was obtained from the black crystal region of Inonotus obliquus by hot water extraction, DEAE-52 cellulose extraction and Sephadex-100 column chromatography purification. Structural analysis indicated that IOP1-1 was a glucan with a main chain composed of α-Glcp-(1 → 4)-α-Glcp-(1 → 4)-β-Glcp-(1 → 4)-β-Glcp-(1 → 4)-α-Glcp-(1 → 6)-β-Glcp-(1 → 4)-α-Glcp-(1 → 3)-β-Glcp-(1→. The CCK-8 assay results showed that IOP1-1 inhibited AsPC-1 and SW1990 pancreatic cancer cell proliferation in a concentration-dependent manner. Flow cytometric analysis revealed that IOP1-1 induced cell cycle arrest in AsPC-1 and SW1990 cells. Hoechst 33342 staining and Annexin V-FITC/PI double staining analysis showed that IOP1-1 could induce apoptosis in AsPC-1 and SW1990 cells. Furthermore, western blot analysis confirmed that IOP1-1 could induce apoptosis in AsPC-1 and SW1990 pancreatic cancer cells through three pathways: the mitochondrial pathway, the death receptor pathway, and endoplasmic reticulum stress. According to these research data, IOP1-1 may be utilized as an adjuvant treatment to anticancer medications, opening up new application prospects and opportunities.

GC/MS and 2D NMR-based approach to evaluate the chemical profile of hydroalcoholic extract from Agaricus blazei Murill and its anti-inflammatory effect on human neutrophils

ETHNOPHARMACOLOGICAL RELEVANCE

Agaricus blazei Murill (AbM) is one of the main mushrooms used for medicinal purposes. The use of AbM in the preparation of teas is widespread mainly in Asian countries, while in Brazil it is used as a functional food to combat inflammatory diseases and cancer.

AIM OF THE STUDY

The main focus of this study was the characterization of the chemical profile of the hydroalcoholic extract of Agaricus blazei Murill (AbE), as well as the evaluation of its cytotoxic and anti-inflammatory potential using human neutrophils.

MATERIALS AND METHODS

The extract was prepared by dynamic maceration using a mixture of ethanol and water (70/30, v v-1) as solvent. The chemical profile characterization was carried out by 2D NMR and GC-MS techniques. The cytotoxicity of AbE was evaluated through studies of hemolytic potential, cell viability and membrane integrity. The anti-inflammatory activity was analyzed by a PMA-induced neutrophil degranulation assay.

RESULTS

Chemical analysis of AbE revealed the presence of 28 metabolites in its composition, with mannitol as the major compound. AbE at 1-200 μg mL-1 and mannitol at 4-160 μg mL-1, showed low hemolytic and cytotoxic potential against human red blood cells and neutrophils. Furthermore, both were able to significantly reduce the release of myeloperoxidase.

CONCLUSIONS

These results indicate that AbE is a promising natural product to be incorporated into pharmaceutical dosage forms intended for the adjuvant treatment of inflammatory diseases.

Extracts from Four Species of Xylotrophic Basidiomycetes Growing in the Middle Urals (Russia) Revealed Cytotoxic Effects on Model Object Drosophila melanogaster

In our study, four species of wood-decaying fungi with perennial fruiting bodies were used as the source of biologically active compounds (BACs) - Inonotus obliquus (chaga), Fomitopsis pinicola, Fomes fomentarius, and Ganoderma applanatum. Fungi have a wide range of secondary metabolites but are used much less frequently than plants in both folk and official medicine. Fungotherapy could be considered a promising trend in the development of modern natural therapy. Therefore, qualitative and quantitative analyses of the extracts were carried out. The cytotoxic and genotoxic effects of aqueous-alcoholic extracts, obtained from fungal fruiting bodies were assessed after application on Drosophila melanogaster. The frequency of the larvae lethally, SMART mosaicism, the GstD1 gene expression and the DNA damage were studied. The addition of 0.5% of fungal extracts to the food substrate did not cause a significant change in the lethality level in D. melanogaster. All extracts caused an increase in the degree of DNA damage. The greatest effect was caused by extract from I. obliquus and G. applanatum. Chaga extract caused a significant increase in the expression level of the GstD1 gene. F. fomentarius extract exhibited the lowest level of DNA damage and reduced GstD1 gene expression. The F. fomentarius extract showed a pronounced antiproliferative effect. So, Drosophila melanogaster could be used as the preliminary test object for early studies of biological activities from natural raw materials as it is much cheaper compared with cell lines and vertebrate models.

A review for cancer treatment with mushroom metabolites through targeting mitochondrial signaling pathway: In vitro and in vivo evaluations, clinical studies and future prospects for mycomedicine

Resistance to apoptosis stands as a roadblock to the successful pharmacological execution of anticancer drug effect. A comprehensive insight into apoptotic signaling pathways and an understanding of the mechanisms of apoptosis resistance are crucial to unveil new drug targets. At this juncture, researchers are heading towards natural sources in particular, mushroom as their potential drugs leads to being the reliable source of potent bioactive compounds. Given the continuous increase in cancer cases, the potent anticancer efficacy of mushrooms has inevitably become a fascinating object to researchers due to their higher safety margin and multitarget. This review aimed to collect and summarize all the available scientific data on mushrooms from their extracts to bioactive molecules in order to suggest their anticancer attributes via a mitochondrion -mediated intrinsic signaling mechanism. Compiled data revealed that bioactive components of mushrooms including polysaccharides, sterols and terpenoids as well as extracts prepared using 15 different solvents from 53 species could be effective in the supportive treatment of 20 various cancers. The underlying therapeutic mechanisms of the studied mushrooms are explored in this review through diverse and complementary investigations: in vitro assays, pre-clinical studies and clinical randomized controlled trials. The processes mainly involved were ROS production, mitochondrial membrane dysfunction, and action of caspase 3, caspase 9, XIAP, cIAP, p53, Bax, and Bcl-2. In summary, the study provides facts pertaining to the potential beneficial effect of mushroom extracts and their active compounds against various types of cancer and is shedding light on the underlying targeted signaling pathways.

Chaga mushroom triterpenoids as adjuncts to minimally invasive cancer therapies: A review

Cancer has become the second leading cause of death in the world. Integrative cancer therapy management is continuously evolving to enhance treatment outcomes. Chaga mushroom (Inonotus obliquus) is a parasitic fungus acclaimed to contain pharmaceutical and nutraceutical value in the fight against cancer. In particular, triterpenoid constituents derived from Chaga mushrooms have been recognized for their anti-cancer activity after distinguished cytotoxicity was repeatedly observed in cancer cells treated in vitro with lipophilic fractions of extract compared to aqueous ones. Studies that investigate the anti-cancer activity of Chaga mushroom triterpenoids are reviewed in this article to determine which cancer cell lines demonstrate the greatest susceptibility to them while highlighting the structure-activity relationships that are involved. Triterpenoid supplementation as an adjunct to cancer treatment may be a viable option as inotodiol and 3-β-22 α-dihydroxylanosta-8, 25-diene-24-one have been shown to exhibit anti-cancer activity similar to that of conventional drugs. Advances in addressing bioavailability challenges are also included in this review as studies include in vivo components.

Therapeutic properties of Inonotus obliquus (Chaga mushroom): A review

Inonotus obliquus, also known as Chaga, is a medicinal mushroom that has been used for therapeutic purposes since the sixteenth century. Collections of folk medicine record the application of Chaga for the treatment of diseases such as gastrointestinal cancer, diabetes, bacterial infection, and liver diseases. Modern research provides scientific evidence of the therapeutic properties of I. obliquus extracts, including anti-inflammatory, antioxidant, anticancer, anti-diabetic, anti-obesity, hepatoprotective, renoprotective, anti-fatigue, antibacterial, and antiviral activities. Various bioactive compounds, including polysaccharides, triterpenoids, polyphenols, and lignin metabolites have been found to be responsible for the health-benefiting properties of I. obliquus. Furthermore, some studies have elucidated the underlying mechanisms of the mushroom's medicinal effects, revealing the compounds' interactions with enzymes or proteins of important pathways. Thus, this review aims to explore available information on the therapeutic potentials of Inonotus obliquus for the development of an effective naturally sourced treatment option.

Beneficial Proapoptotic Effect of Heterobasidion Annosum Extract in Colorectal Cancer Xenograft Mouse Model

Fungal extracts possess potential anticancer activity against many malignant neoplastic diseases. In this research, we focused on the evaluation of Heterobasidion annosum (HA) extract in colorectal cancer in an in vivo model. The mice with implanted DLD-1 human cancer cells were given HA extract, the referential drug-5-fluorouracil (5FU), or were treated with its combination. Thereafter, tumor volume was measured and apoptotic proteins such as caspase-8, caspase-3, p53, Bcl-2, and survivin were analyzed in mice serum with an ELISA assay. The Ki-67 protein was assessed in tumor cells by immunohistochemical examination. The biggest volumes of tumors were confirmed in the DLD-1 group, while the lowest were observed in the population treated with 5FU and/or HA extract. The assessment of apoptosis showed increased concentrations of caspase 8 and p53 protein after the combined administration of 5FU and HA extract. The levels of survivin and Bcl-2 were decreased in all tested groups compared to the DLD-1 group. Moreover, we observed a positive reaction for Ki-67 protein in all tested groups. Our findings confirm the apoptotic effect of extract given alone or with 5FU. The obtained results are innovative and provide a basis for further research concerning the antitumor activity of the HA extract, especially in the range of its interaction with an anticancer chemotherapeutic agent.

Nutraceutical potential of mushroom bioactive metabolites and their food functionality

Numerous mushroom bioactive metabolites, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been studied in life-threatening conditions and diseases such as diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity attempting to identify natural therapies. These bioactive metabolites have shown potential as antiviral and immune system strengthener natural agents through diverse cellular and physiological pathways modulation with no toxicity evidence, widely available, and inexpensive. In light of the emerging literature, this paper compiles the most recent information describing the molecular mechanisms that underlie the nutraceutical potentials of these mushroom metabolites suggesting their effectiveness if combined with existing drug therapies while discussing the food functionality of mushrooms. The findings raise hope that these mushroom bioactive metabolites may be utilized as natural therapies considering their therapeutic potential while anticipating further research designing clinical trials and developing new drug therapies while encouraging their consumption as a natural adjuvant in preventing and controlling life-threatening conditions and diseases. PRACTICAL APPLICATIONS: Diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity are among the world's largest life-threatening conditions and diseases. Several mushroom bioactive compounds, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been found potential in tackling these diseases through diverse cellular and physiological pathways modulation with no toxicity evidence, suggesting their use as nutraceutical foods in preventing and controlling these life-threatening conditions and diseases.

Treasures from the forest: Evaluation of mushroom extracts as anti-cancer agents

Mushrooms provide a reliable source of bioactive compounds and have numerous nutritional values, which is one of the reasons why they are widely used for culinary purposes. They may also be a remedy for several medical conditions, including cancer diseases. Given the constantly increasing number of cancer incidents, the great anticancer potential of mushrooms has unsurprisingly become an object of interest to researchers. Therefore, this review aimed to collect and summarize all the available scientific data on the anti-cancer activity of mushroom extracts. Our research showed that mushroom extracts from 92 species, prepared using 12 different solvents, could reduce the viability of 38 various cancers. Additionally, we evaluated different experimental models: in vitro (cell model), in vivo (mice and rat model, case studies and randomized controlled trials), and in silico. Breast cancer proved to be sensitive to the highest number of mushroom extracts. The curative mechanisms of the studied mushrooms consisted in: inhibition of cancer cell proliferation, unregulated proportion of cells in cell cycle phases, induction of autophagy and phagocytosis, improved response of the immune system, and induction of apoptotic death of cells via upregulation of pro-apoptotic factors and downregulation of anti-apoptotic genes. The processes mainly involved the expression of caspases -3, -8, -9, AKT, p27, p53, BAX, and BCL2. The quoted results could lead to the classification of mushrooms as nutraceuticals used to prevent a variety of disorders or to support treatment of cancer diseases.

Inhibitory effect of triterpenoids from the mushroom Inonotus obliquus against α-glucosidase and their interaction: Inhibition kinetics and molecular stimulations

Bioassay-guided fractionation led to the isolation of a series of triterpenoids (1-46) including 12 new ones (1-12) from the mushroom Inonotus obliquus. The structures of all the compounds were elucidated by spectroscopic analysis as well as by comparison with literature data. Triterpenoids 1-3, 6, 7, 16, 24, 25, 27, 38, 43, 44 and 46 showed strong α-glucosidase inhibition, with IC₅₀ values from 11.5 to 81.8 μM. Their structure-activity relationships were discussed. Inonotusol F (24) showed the strongest inhibitory activity and it presented noncompetitive inhibition against α-glucosidase. Molecular docking and molecular dynamics stimulation further demonstrated that GLU302 and PHE298 were key amino acids for the inhibition of inonotusol F (24) towards α-glucosidase. This study indicates the vital role of triterpenoids in explaining hypoglycemic effect of Inonotus obliquus and provides important evidence for further development and utilization of this mushroom.

Lappaconitine hydrochloride inhibits proliferation and induces apoptosis in human colon cancer HCT-116 cells via mitochondrial and MAPK pathway

Lappaconitine hydrochloride (LH), as a new synthetic alkaloid, exhibits antitumor activity, whereas its antitumor effect on colorectal cancer (CRC) has not been investigated. In this study, the effect of LH on HCT-116 cell proliferation and apoptosis in vivo and in vitro and underlying molecular mechanism were explored. The Cell Counting Kit-8 (CCK-8) was used to assess cell viability. Morphological change was observed by Hoechst 33342 staining. Cell cycle and apoptosis were performed using a flow cytometer. The western blot method was used to screen for related protein expression. The mitochondrial membrane potential (MMP) was confirmed using the 5, 5, 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethylbenzimi-dazolyl carbo cyanine iodide (JC-1) staining assay. Reactive oxygen species (ROS) was evaluated by a 20-70-dichlorofluorescein diacetate (DCFH-DA) staining assay. The antitumor effect was evaluated in vivo by the xenograft HCT-116 model. The results showed that LH significantly inhibited cell viability in a time- and concentration-dependent manner. LH induced apoptosis and S phase cell cycle arrest. LH promoted the reduction of MMP and ROS accumulation. Moreover, LH activated the mitochondrial and MAPK pathway. The experiments in vivo showed that LH had significant antitumor effect in tumor-bearing mice, and had virtually no effect on the weight and internal organs of the mice. In conclusion, LH could induce apoptosis in HCT-116 cells through mitochondrial and MAPK signaling pathways. LH may be a promising treatment for CRC.

Inonotus obliquus - from folk medicine to clinical use

The Inonotus obliquus (I. obliquus) mushroom was traditionally used to treat various gastrointestinal diseases. For many years, mounting evidence has indicated the potential of I. obliquus extracts for treatment of viral and parasitic infections. Furthermore, substances from I. obiquus have been shown to stimulate the immune system. The most promising finding was the demonstration that I. obliquus has hypoglycemic and insulin sensitivity potential. This review summarizes the therapeutic potential of I. obliquus extracts in counteracting the progression of cancers and diabetes mellitus as well as their antiviral and antiparasitic activities and antioxidant role. As shown by literature data, various authors have tried to determine the molecular mechanism of action of I. obliquus extracts. Two mechanisms of action of I. obliquus extracts are currently emerging. The first is associated with the broad-sense impact on antioxidant enzymes and the level of reactive oxygen species (ROS). The other is related to peroxisome proliferator-activated receptor gamma (PPARγ) effects. This receptor may be a key factor in the anti-inflammatory, antioxidant, and anti-cancer activity of I. obliquus extracts. It can be concluded that I. obliquus fits the definition of functional food and has a potentially positive effect on health beyond basic nutrition; however, studies that meet the evidence-based medicine (EBM) criteria are needed.

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Extracts or polysaccharides from I. obliquus exhibit an anti-cancer potential in vitro.

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Extracts or polysaccharides from I. obliquus exhibit anti-inflammation potential.

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Extracts or polysaccharides from I. obliquus exhibit hypoglycemic and insulin sensitivity potential.

Inotodiol inhibits cells migration and invasion and induces apoptosis via p53-dependent pathway in HeLa cells

BACKGROUND

Inonotus obliquus, namely as Chaga mushroom, is a medicinal and edible fungus, which is widely used in food and medical fields. Inotodiol, a natural lanostane-type triterpenoid with remarkable pharmacological activities, was isolated from Inonotus obliquus, which its potential anti-tumor molecular mechanism was elaborated poorly.

PURPOSE

The aim of the present study was to investigate the effect of Inotodiol on HeLa cell migration, invasion and apoptosis through p53-dependent pathway.

STUDY DESIGN AND METHODS

The potential mechanisms of Inotodiol on HeLa cell anti-metastatic and pro-apoptosis via wound healing assay, trans-well invasion assay, flow cytometry, caspase-3 activity assay and western blot analysis were studied, as well as the involvement of p53 signaling pathway in anti-metastatic and pro-apoptosis of Inotodiol. Besides, the function of tumor suppressor p53 was further verified by small interfering RNA.

RESULTS

Firstly, the cell viability assay showed that low-concentration of Inotodiol had no cytotoxicity to HeLa cells and whereas the concentration above 25 μM significantly inhibited HeLa cell growth and even induced apoptosis. This result was further demonstrated by cell proliferation and morphology assay. Secondly, in vitro wound healing and trans-well invasion assays reported that low-concentration treatment of Inotodiol significantly inhibited cells migration and invasion in a dose-dependent manner, the western blot analysis of matrix mettalloprotinase-2 (MMP2) and matrix mettalloprotinase-9 (MMP9) levels were also decreased. Moreover, Inotodiol notably induced tumor cell apoptosis by Annexin-V-FITC apoptosis assay, which is associated with activation pro-apoptotic proteins of PARP, cleaved caspase-3 and Bax expression, inhibition anti-apoptotic protein Bcl-2 expression. Finally, the anti-tumor activity of Inotodiol was attenuated by silencing p53 tumor suppressor, the result revealed that pre-treatment with p53-specific small interfering RNA (si-p53) markedly inhibited Intodiol-indeuced HeLa cell apoptosis and decreased the caspase-3 activity. What is more, the inhibitory effect of Inotodiol on tumor migration and invasion was blocked under p53 knockdown.

CONCLUSION

To sum up, the present study indicated that Inotodiol possessed the potential to prevent malignant tumor migration and invasion, and it might be a natural active compound candidate for clinical treatment of human cervical cancer.

Medicinal mushrooms as an attractive new source of natural compounds for future cancer therapy

Medicinal mushrooms have been used throughout the history of mankind for treatment of various diseases including cancer. Nowadays they have been intensively studied in order to reveal the chemical nature and mechanisms of action of their biomedical capacity. Targeted treatment of cancer, non-harmful for healthy tissues, has become a desired goal in recent decades and compounds of fungal origin provide a vast reservoir of potential innovational drugs. Here, on example of four mushrooms common for use in Asian and Far Eastern folk medicine we demonstrate the complex and multilevel nature of their anticancer potential, basing upon different groups of compounds that can simultaneously target diverse biological processes relevant for cancer treatment, focusing on targeted approaches specific to malignant tissues. We show that some aspects of fungotherapy of tumors are studied relatively well, while others are still waiting to be fully unraveled. We also pay attention to the cancer types that are especially susceptible to the fungal treatments.

A mechanism for semaphorin-induced apoptosis: DNA damage of endothelial and myogenic cells in primary cultures from skeletal muscle

One hallmark of cancer is its ability to recruit a vascular supply to support rapid growth. Suppression of angiogenesis holds potential as a second-line or adjuvant therapy to stunt cancer growth, progression, metastasis, and post-resection regeneration. To begin to test the hypothesis that semaphorin 3A and 3F together, will induce endothelial cell apoptosis by inducing DNA damage, mixed primary cultures isolated from normal adult mouse skeletal muscle were treated for 48 hr with Sema3A ± Sema3F (100ng/mL). Changes in surviving-cell density, DNA synthesis, DNA repair (gamma-Histone 2AX, γH2AX, an indirect measure for DNA damage), and apoptotic DNA fragmentation (TUNEL staining) were assayed in cultures of CD31+ endothelial and desmin+ muscle cells. Sema3F increased DNA damage-associated DNA repair in both cell types. Co-treatment with Sema3A+3F increased γH2AX staining ~25-fold over control levels, and further increased apoptosis compared to control and Sema3A alone. Results were negated by treatment with neutralizing anti-semaphorin antibodies and are interpreted as suggesting that Sema3A may sensitize endothelial but not muscle cells to Sema3F-induced DNA damage. These preliminary findings on a complex system of interacting cells may contribute to developing applications that could target angiogenic regulatory mechanisms for their therapeutic potential against cancer progression and metastasis.