Identification of potential targets for differentiation in human leukemia cells induced by diallyl disulfide

Diallyl disulfide antagonizes DJ-1 mediated proliferation, epithelial-mesenchymal transition, and chemoresistance in gastric cancer cells

Diallyl disulfide (DADS), an organic component of allicin abstracted from garlic, possesses multi-target antitumor activity. DJ-1 performs a vital function in promoting AKT aberrant activation via down-regulating phosphatase and tensin homologue (PTEN) in tumors. It is unknown the involvement of DJ-1 in epithelial-mesenchymal transition (EMT) of gastric cancer (GC) cells. The purpose of this study is to investigate whether diallyl disulfide (DADS) intervenes in the role of DJ-1 in GC. Based on the identification that the correlation between high DJ-1 and low PTEN expression in GC was implicated in clinical progression, we illuminated that down-regulation of DJ-1 by DADS aided in an increase in PTEN expression and a decrease in phosphorylated AKT levels, which was in line with the results manifested in the DJ-1 knockdown and overexpressed cells, concurrently inhibiting proliferation, EMT, migration, and invasion. Furthermore, the antagonistic effects of DADS on DJ-1 were observed in in vivo experiments. Additionally, DADS mitigated the DJ-1-associated drug resistance. The current study revealed that DJ-1 is one of potential targets for DADS, which hopefully provides a promising strategy for prevention and adjuvant chemotherapy of GC.

Diallyl disulfide downregulating RhoGDI2 induces differentiation and inhibit invasion via the Rac1/Pak1/LIMK1 pathway in human leukemia HL-60 cells

Leukemia is a type of disease in which hematopoietic stem cells proliferate clonally at the genetic level. We discovered previously by high-resolution mass spectrometry that diallyl disulfide (DADS), which is one of the effective ingredients of garlic, reduces the performance of RhoGDI2 from APL HL-60 cells. Although RhoGDI2 is oversubscribed in several cancer categories, the effect of RhoGDI2 in HL-60 cells has remained unexplained. We aimed to investigate the influence of RhoGDI2 on DADS-induced differentiation of HL-60 cells to elucidate the association among the effect of inhibition or over-expression of RhoGDI2 with HL-60 cell polarization, migration and invasion, which is important for establishing a novel generation of inducers to elicit leukemia cell polarization. Co-transfection with RhoGDI2-targeted miRNAs apparently decreases the malignant biological behavior of cells and upregulates cytopenias in DADS-treated HL-60 cell lines, which increases CD11b and decreases CD33 and mRNA levels of Rac1, PAK1 and LIMK1. Meanwhile, we generated HL-60 cell lines with high-expressing RhoGDI2. The proliferation, migration and invasion capacity of such cells were significantly increased by the treated with DADS, while the reduction capacity of the cells was decreased. There was a reduction in CD11b and an increase in CD33 production, as well as an increase in the mRNA levels of Rac1, PAK1 and LIMK1. It also confirmed that inhibition of RhoGDI2 attenuates the EMT cascade via the Rac1/Pak1/LIMK1 pathway, thereby inhibiting the malignant biological behavior of HL-60 cells. Thus, we considered that inhibition of RhoGDI2 expression might be a new therapeutic direction for the treatment of human promyelocytic leukemia. The anti-cancer property of DADS against HL-60 leukemia cells might be regulated by RhoGDI2 through the Rac1-Pak1-LIMK1 pathway, which provides new evidence for DADS as a clinical anti-cancer medicine.

From Natural Sources to Synthetic Derivatives: The Allyl Motif as a Powerful Tool for Fragment-Based Design in Cancer Treatment

Since the beginning of history, natural products have been an abundant source of bioactive molecules for the treatment of different diseases, including cancer. Many allyl derivatives, which have shown anticancer activity both in vitro and in vivo in a large number of cancers, are bioactive molecules found in garlic, cinnamon, nutmeg, or mustard. In addition, synthetic products containing allyl fragments have been developed showing potent anticancer properties. Of particular note is the allyl derivative 17-AAG, which has been evaluated in Phase I and Phase II/III clinical trials for the treatment of multiple myeloma, metastatic melanoma, renal cancer, and breast cancer. In this Perspective, we compile extensive literature evidence with descriptions and discussions of the most recent advances in different natural and synthetic allyl derivatives that could generate cancer drug candidates in the near future.

In Vitro Antitumor and Anti-Inflammatory Activities of Allium-Derived Compounds Propyl Propane Thiosulfonate (PTSO) and Propyl Propane Thiosulfinate (PTS)

Increasing rates of cancer incidence and the side-effects of current chemotherapeutic treatments have led to the research on novel anticancer products based on dietary compounds. The use of Allium metabolites and extracts has been proposed to reduce the proliferation of tumor cells by several mechanisms. In this study, we have shown the in vitro anti-proliferative and anti-inflammatory effect of two onion-derived metabolites propyl propane thiosulfinate (PTS) and propyl propane thiosulfonate (PTSO) on several human tumor lines (MCF-7, T-84, A-549, HT-29, Panc-1, Jurkat, PC-3, SW-837, and T1-73). We observed that this effect was related to their ability to induce apoptosis regulated by oxidative stress. In addition, both compounds were also able to reduce the levels of some pro-inflammatory cytokines, such as IL-8, IL-6, and IL-17. Therefore, PTS and PTSO may have a promising role in cancer prevention and/or treatment.

Diallyl Disulfide: A Bioactive Garlic Compound with Anticancer Potential

Cancer is a life-threatening disease caused by the uncontrolled division of cells, which culminates in a solid mass of cells known as a tumor or liquid cancer. It is the leading cause of mortality worldwide, and the number of cancer patients has been increasing at an alarming rate, with an estimated 20 million cases expected by 2030. Thus, the use of complementary or alternative therapeutic techniques that can help prevent cancer has been the subject of increased attention. Garlic, the most widely used plant medicinal product, exhibits a wide spectrum of biological activities, including antibacterial, hypo-lipidemic, antithrombotic, and anticancer effects. Diallyl disulfide (DADS) is a major organosulfur compound contained within garlic. Recently, several experimental studies have demonstrated that DADS exhibits anti-tumor activity against many types of tumor cells, including gynecological cancers (cervical cancer, ovarian cancer), hematological cancers (leukemia, lymphoma), lung cancer, neural cancer, skin cancer, prostate cancer, gastrointestinal tract and associated cancers (esophageal cancer, gastric cancer, colorectal cancer), hepatocellular cancer cell line, etc. The mechanisms behind the anticancer action of DADS include epithelial-mesenchymal transition (EMT), invasion, and migration. This article aims to review the available information regarding the anti-cancer potential of DADS, as well as summarize its mechanisms of action, bioavailability, and pharmacokinetics from published clinical and toxicity studies.

Antileukaemic Cell Proliferation and Cytotoxic Activity of Edible Golden Cordyceps (Cordyceps militaris) Extracts

Golden cordyceps (Cordyceps militaris) is a mushroom of the genus Cordyceps. It has been used as a food supplement for both healthy and ill people. In this study, the antileukaemic cell proliferation activities of golden cordyceps extracts were examined and compared with standard cordycepin (CDCP) in EoL-1, U937, and KG-1a cells. Wilms' tumour 1 (WT1) protein was used as a biomarker of leukaemic cell proliferation. The cytotoxicity of the extracts on leukaemic cells was determined using the MTT assay. Their inhibitory effects on WT1 protein expression and cell cycle progression of EoL-1 cells were investigated using Western blotting and flow cytometry, respectively. Induction of KG-1a cell differentiation (using CD11b as a marker) was determined using flow cytometry. The golden cordyceps extracts exhibited cytotoxic effects on leukaemic cells with the highest IC₅₀ value of 16.5 ± 3.9 µg/mL, while there was no effect on normal blood cells. The expression levels of WT1 protein in EoL-1 cells were decreased after treatment with the extracts. Moreover, cell cycle progression and cell proliferation were inhibited. The levels of CD11b increased slightly following the treatment. All these findings confirm the antileukaemic proliferation activity of golden cordyceps.

Biological Functions of Diallyl Disulfide, a Garlic-Derived Natural Organic Sulfur Compound

Garlic is widely accepted as a functional food and an excellent source of pharmacologically active ingredients. Diallyl disulfide (DADS), a major bioactive component of garlic, has several beneficial biological functions, including anti-inflammatory, antioxidant, antimicrobial, cardiovascular protective, neuroprotective, and anticancer activities. This review systematically evaluated the biological functions of DADS and discussed the underlying molecular mechanisms of these functions. We hope that this review provides guidance and insight into the current literature and enables future research and the development of DADS for intervention and treatment of multiple diseases.

Improving the bioavailability and bioactivity of garlic bioactive compounds via nanotechnology

This review highlights main bioactive compounds and important biological functions especially anticancer effects of the garlic. In addition, we review current literature on the stability and bioavailability of garlic components. Finally, this review aims to provide a potential strategy for using nanotechnology to increase the stability and solubility of garlic components, providing guidelines for the qualities of garlic products to improve their absorption and prevent their early degradation, and extend their circulation time in the body. The application of nanotechnology to improve the bioavailability and targeting of garlic compounds are expected to provide a theoretical basis for the functional components of garlic to treat human health. We review the improvement of bioavailability and bioactivity of garlic bioactive compounds via nanotechnology, which could promisingly overcome the limitations of conventional garlic products, and would be used to prevent and treat cancer and other diseases in the near future.

Hypoxia-induced up-regulation of miR-27a promotes paclitaxel resistance in ovarian cancer

Ovarian cancer (OC) is a malignant tumor with high mortality in women. Although cancer patients initially respond to paclitaxel chemotherapy following surgery, most patients will relapse after 12-24 months and gradually die from chemotherapy resistance. In OC, cancer cells become resistant to paclitaxel chemotherapy under hypoxic environment. The miR-27a has been identified as an oncogenic molecular in ovarian cancer, prostate cancer, liver cancer etc. In addition, the miR-27a is involved in hypoxia-induced chemoresistance in various cancers. However, the role of miR-27a in hypoxia-induced OC resistance remains unclear. The aim of the present study was to investigate the regulatory mechanism of miR-27a in hypoxia-induced OC resistance. The expression of HIF-1α induced Hypoxia overtly up-regulated. At the same time, hypoxia increased viability of Skov3 cells and decreased cell apoptosis when treated with paclitaxel. The expression of the miR-27a was obviously up-regulated under hypoxia and involved in hypoxia-induced paclitaxel resistance. Follow-up experiments portray that miR-27a improved paclitaxel resistance by restraining the expression of APAF1 in OC. Finally, we further elucidated the important regulatory role of the miR-27a-APAF1 axis in OC through in vivo experiments. According to our knowledge, we first reported the regulation of miR-27a in hypoxia-induced chemoresistance in OC, providing a possible target for chemoresistance treatment of OC.

Anticancer potential of garlic and its bioactive constituents: A systematic and comprehensive review

Vegetables of the Allium genus, such as garlic (Allium sativum L.), onions, shallots, leaks, and chives, have been used for many years for food consumption and for medicinal purposes. Historical medical texts have indicated the therapeutic applications of garlic as an antitumor, laxative, diuretic, antibacterial and antifungal agent. Specifically, garlic's antitumor abilities have been traced back 3500 years as a chemotherapeutic agent used in Egypt. Other beneficial effects of garlic consumption include lowering blood pressure, blood cholesterol, sugar and lipids. The processing and aging of garlic result in the production of non-toxic organosulfur by-products. These sulfur-containing compounds, such as allicin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, alliin, S-allylcysteine, and S-allylmercaptocysteine, impact various stages of carcinogenesis. The anticancer mechanisms of action of these garlic-derived phytochemicals include altering mitochondrial permeability, inhibiting angiogenesis, enhancing antioxidative and proapoptotic properties, and regulating cell proliferation. All these effects of garlic's sulfur-compounds have been demonstrated in various human cancers. The intent of this literature research is to explore the potential of garlic-derived products and bioactive organosulfur compounds as cancer chemopreventive and chemotherapeutic agents. This investigation employs criteria for systematic review and critically analyzes published in vitro, in vivo and clinical studies. Concerns and limitations that have arisen in past studies regarding standards of measurement, bioavailability, and method of delivery are addressed. Overall, it is hoped that through this systematic and comprehensive review, future researchers can be acquainted with the updated data assembled on anticancer properties of garlic and its phytoconstituents.

Knockdown of RhoGDI2 represses human gastric cancer cell proliferation, invasion and drug resistance via the Rac1/Pak1/LIMK1 pathway

Gastric cancer (GC) is the fifth most common primary malignancy in humans. Rho GDP dissociation inhibitor 2 (RhoGDI2) is overexpressed in multiple cancer types, but the role of RhoGDI2 in GC has not been elucidated. This study aims to determine the level of RhoGDI2 in GC and to confirm the effect of its inhibition or overexpression on GC cell migration, invasion and chemosensitivity. RhoGDI2 level is significantly enhanced in human GC tissue samples in comparison with normal gastric epithelium and corresponding para-cancerous samples. The expression of RhoGDI2 is correlated with clinicopathological parameters and prognosis. Transfection in combination with miRNA targeting of RhoGDI2 in GC cell lines remarkably downregulates GC cell migration and invasion and reduces the mRNA levels of Rac1, Pak1 and LIMK1. The inhibition of RhoGDI2 downregulates GC cell migration and invasion by attenuating the EMT cascade via the Rac1/Pak1/LIMK1 pathway. Knockdown of RhoGDI2 is a potential therapeutic strategy for GC.

Novel Insights into PARK7 (DJ-1), a Potential Anti-Cancer Therapeutic Target, and Implications for Cancer Progression

The expression of PARK7 is upregulated in various types of cancer, suggesting its potential role as a critical regulator of the pathogenesis of cancer and in the treatment of cancer and neurodegenerative diseases, including Parkinson’s disease, Alzheimer’s disease, and Huntington disease. PARK7 activates various intracellular signaling pathways that have been implicated in the induction of tumor progression, which subsequently enhances tumor initiation, continued proliferation, metastasis, recurrence, and resistance to chemotherapy. Additionally, secreted PARK7 has been identified as a high-risk factor for the pathogenesis and survival of various cancers. This review summarizes the current understanding of the correlation between the expression of PARK7 and tumor progression.

Diallyl disulfide induces downregulation and inactivation of cofilin 1 differentiation via the Rac1/ROCK1/LIMK1 pathway in leukemia cells

Cofilin is associated with cell differentiation; however, to the best of our knowledge, no data have indicated an association between the cofilin 1 pathway and leukemia cell differentiation. The present study investigated the involvement of the cofilin 1 signaling pathway in diallyl disulfide (DADS)-induced differentiation and the inhibitory effects on the proliferation, migration, and invasion of human leukemia HL-60 cells. First, it was identified that 8 µM DADS suppressed cell proliferation, migration and invasion, and induced differentiation based on the reduced nitroblue tetrazolium ability and increased CD11b and CD33 expression. DADS significantly downregulated the expression of cofilin 1 and phosphorylated cofilin 1 in HL-60 leukemia cells. Second, it was verified that silencing cofilin 1 markedly promoted 8 µM DADS-induced differentiation and the inhibitory effect on cell proliferation and invasion. Overexpression of cofilin 1 obviously suppressed 8 µM DADS-induced differentiation and the inhibitory effect on cell proliferation and invasion. Third, the present study examined the mechanisms by which 8 µM DADS decreases cofilin 1 expression and activation. The results revealed that 8 µM DADS inhibited the mRNA and protein expression of Rac1, Rho-associated protein kinase 1 (ROCK1) and LIM domain kinase 1 (LIMK1) as well as the phosphorylation of LIMK1 in HL-60 cells, while 8 µM DADS enhanced the effects of the Rac1-ROCK1-LIMK1 pathway in cells overexpressing cofilin 1 compared with that in control HL-60 cells. These results suggest that the anticancer function of DADS on HL-60 leukemia cells is regulated by the Rac1-ROCK1-LIMK1-cofilin 1 pathway, indicating that DADS could be a promising anti-leukemia therapeutic compound.

Diallyl disulfide inhibits colon cancer metastasis by suppressing Rac1-mediated epithelial-mesenchymal transition

Background

Prevention of epithelial-mesenchymal transition (EMT) provides a novel treatment strategy for tumor metastasis. Our previous studies have shown that diallyl disulfide (DADS) inhibits Ras related C3 botulinum toxin substrate1 (Rac1) expression, being a potential agent that suppresses migration and invasion of colon cancer cells. The study provides information on the underlying mechanisms.

Methods

The expression of Rac1 and EMT markers (vimentin, N-cadherin and E-cadherin) in colon cancer samples was detected. Colon cancer cell lines treated with or without DADS were used to examine EMT markers, Rac1 and its related molecules. Various cell functions related to metastasis were performed in vitro, and further confirmed in vivo.

Results

Rac1 was highly expressed in colon cancer, and associated with aberrant expression of EMT markers and poor prognosis. Rac1 overexpression induced cell migration and invasion in vitro and metastasis in vivo with down-regulation of E-cadherin and up-regulation of N-cadherin, vimentin, and snail1, whereas inhibition of Rac1 impaired the oncogenic function. DADS suppressed Rac1 expression and activity via inhibition of PI3K/Akt pathway, thus suppressing EMT and invasion and migration of colon cancer cells. The tumor inhibition of DADS was enhanced by knockdown of Rac1, but antagonized by overexpression of Rac1. We further found that DADS blocked EMT via targeting the Rac1-mediated PAK1-LIMK1-Cofilins signaling.

Conclusion

Rac1 is a potential target molecule for the inhibitory effect of DADS on EMT and invasion and metastasis of colon cancer cells.

The garlic allelochemical DADS influences cucumber root growth involved in regulating hormone levels and modulating cell cycling

Most allelochemicals are phytotoxic to the receiver plants and may influence the cell micro- and ultrastructure, cell division, phytohormone levels, and ultimately growth. In order to understand the allelopathic potential of garlic, the effects of its main bioactive allelochemical diallyl disulfide (DADS), experiments were carried out to observe the seed germination, root growth, and developmental responses in cucumber seedlings treated with various concentrations of DADS. The obtained data suggested active influence of DADS on cucumber root growth and development. Significant responses were observed in early root growth and elongation, mitotic cell division and elongation, and root architecture modulation. The effect, however, was dose dependent, and lower concentrations of DADS proved to be promotional whereas higher concentrations of DADS inhibited cucumber root growth and development. Relative root elongation (RRE) revealed that DADS could increase growth of cucumber roots in the early developmental days. Moreover, DADS application significantly influenced mitosis-related gene expression. Observed genes CYCA and CDKB were initially downregulated in the first 24 h but significantly upregulated after 48 h, while gene CDKA was upregulated in the first 24 h. Similarly, DADS application significantly altered primary plant hormones, such as IAA, ABA, GA₃, and ZR, in the cucumber roots. Taken together, low concentrations of DADS treatment could promote cucumber root growth and induce main root elongation by upregulating CDKA and CDKB gene expression and regulating hormone balance in root. The current findings offer insight into the allelopathic potential of garlic allelochemical DADS and can be considered vital for establishing plant allelopathic studies.