Cytotoxicity of alkaloids isolated from Peganum harmala seeds on HCT116 human colon cancer cells.

BACKGROUND: The present study aimed to elucidate the potential anticancer activity and mechanism of P. harmala's alkaloid extract, harmine (HAR), and harmaline (HAL) in HCT-116 colorectal cancer cells. METHODS AND RESULTS: P. harmala's alkaloid was extracted from harmala seeds. HCT-116 cells were treated with P. harmala's alkaloid extract, HAR and HAL. Cytotoxicity was determined by MTT assay, apoptotic activity detected via flow cytometry and acridine orange (AO)/ethidium bromide (EB) dual staining, and cell cycle distribution analyzed with flow cytometry. The mRNA expression of Bcl-2-associated X protein (Bax) and glycogen synthase kinase-3 beta (GSK3ß) was measured by real-time PCR. Furthermore, the expression of Bax, Bcl-2, GSK3ß and p53 proteins, were determined by western blotting. The findings indicated that, P. harmala's alkaloids extract, HAR and HAL were significantly cytotoxic toward HCT116 cells after 24 and 48 h of treatment. We showed that P. harmala's alkaloid extract induce apoptosis and cell cycle arrest at G2 phase in the HCT116 cell line. Downregulation of GSK3ß and Bcl-2 and upregulation of Bax and p53 were observed. CONCLUSION: The findings of this study indicate that the P. harmala's alkaloid extract has anticancer activity and may be further investigated to develop future anticancer chemotherapeutic agents.

Discovery of harmiprims, harmine-primaquine hybrids, as potent and selective anticancer and antimalarial compounds.

Although cancer and malaria are not etiologically nor pathophysiologically connected, due to their similarities successful repurposing of antimalarial drugs for cancer and vice-versa is known and used in clinical settings and drug research and discovery. With the growing resistance of cancer cells and Plasmodium to the known drugs, there is an urgent need to discover new chemotypes and enrich anticancer and antimalarial drug portfolios. In this paper, we present the design and synthesis of harmiprims, hybrids composed of harmine, an alkaloid of the ß-carboline type bearing anticancer and antiplasmodial activities, and primaquine, 8-aminoquinoline antimalarial drug with low antiproliferative activity, covalently bound via triazole or urea. Evaluation of their antiproliferative activities in vitro revealed that N-9 substituted triazole-type harmiprime was the most selective compound against MCF-7, whereas C1-substituted ureido-type hybrid was the most active compound against all cell lines tested. On the other hand, dimeric harmiprime was not toxic at all. Although spectrophotometric studies and thermal denaturation experiments indicated binding of harmiprims to the ds-DNA groove, cell localization showed that harmiprims do not enter cell nucleus nor mitochondria, thus no inhibition of DNA-related processes can be expected. Cell cycle analysis revealed that C1-substituted ureido-type hybrid induced a G1 arrest and reduced the number of cells in the S phase after 24 h, persisting at 48 h, albeit with a less significant increase in G1, possibly due to adaptive cellular responses. In contrast, N-9 substituted triazole-type harmiprime exhibited less pronounced effects on the cell cycle, particularly after 48 h, which is consistent with its moderate activity against the MCF-7 cell line. On the other hand, screening of their antiplasmodial activities against the erythrocytic, hepatic, and gametocytic stages of the Plasmodium life cycle showed that dimeric harmiprime exerts powerful triple-stage antiplasmodial activity, while computational analysis showed its binding within the ATP binding site of PfHsp90.

The roles of autophagy, ferroptosis and pyroptosis in the anti-ovarian cancer mechanism of harmine and their crosstalk.

This study aimed to investigate the role of autophagy, ferroptosis, and pyroptosis in the antitumour mechanism of harmine (Har) and its crosstalk in ovarian cancer. By transmission electron microscopy, we found that compared with those in the control group, the cytoplasm of human ovarian cancer cells (SKOV3) treated with Har showed increased numbers of autophagic vesicles, decreased intracellular mitochondrial volume, increased bilayer membrane density, and decreased cristae. Western blot, immunofluorescence, and monodasylcadaverine (MDC) staining all suggested that Har promoted autophagy in SKOV3 cells. LY294002 and siFOXO3 rescued the inhibition of the PI3K/AKT/mTOR/FOXO3 signalling pathway and the promotion of autophagy by Har. Additionally, the levels of ferroptosis- and pyroptosis-related proteins and the levels of Fe2+ , glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) suggested that Har promoted ferroptosis and pyroptosis in SKOV3 cells. Interestingly, pretreatment with chloroquine (CQ), erastin, rapamycin (Rap), or ferrostatin-1 (Fer-1) increased or reversed the ferroptosis and pyroptosis promoted by Har, respectively. In vivo, the volume of tumours in the Har group was decreased, and immunohistochemistry revealed decreased levels of Ki-67 and GPX4 and increased levels of ATG5 and NARL3. In conclusion, Har exerts its anti-ovarian cancer effect not only by promoting autophagy by regulating the PI3K/AKT/mTOR/FOXO3 signalling pathway but also by promoting ferroptosis and pyroptosis. Additionally, there is complex crosstalk between autophagy, ferroptosis, and pyroptosis in ovarian cancer.

Harmine ameliorates CCl4-induced acute liver injury through suppression of autophagy and inflammation.

CCl4-induced acute liver injury (ALI) is characterized by heightened autophagy, inflammation, and oxidative damage. Accumulating evidence suggests that harmine exerts beneficial effects in countering CCl4-induced ALI by mitigating inflammation and oxidative stress. However, the impact of autophagy on CCl4-induced ALI and the protective role of harmine remain unclear. This study aimed to investigate the potential protective effects of harmine against CCl4-induced ALI in mice by suppressing autophagy and inflammation. Male Kunming mice were orally administered harmine or bifendate for seven days. Subsequently, one hour after the final administration, the model group and treatment groups were intraperitoneally injected with CCl4 to induce ALI. The findings revealed that harmine significantly reduced the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum, and ameliorated the liver histopathological changes induced by CCl4. Furthermore, harmine diminished the levels of TNF-α and IL-6, restored the levels of glutathione (GSH) and superoxide dismutase (SOD), and suppressed the production of nitric oxide (NO) and malondialdehyde (MDA) in the liver. Mechanistically, harmine down-regulated LC3B II/I, p38 MAPK, TLR4, and NF-κB levels, while upregulating p62, Bcl-2, Beclin1, ULK1, and p-mTOR expression. In conclusion, harmine mitigated CCl4-induced ALI by inhibiting autophagy and inflammation through the p38 MAPK/mTOR autophagy pathway, the Bcl-2/Beclin1 pathway, and the TLR4/NF-κB pathway.

Evaluation of the Therapeutic Effects of Harmine on Anaplastic Thyroid Cancer Cells.

Anaplastic thyroid carcinoma (ATC) is an extremely difficult disease to tackle, with an overall patient survival of only a few months. The currently used therapeutic drugs, such as kinase inhibitors or immune checkpoint inhibitors, can prolong patient survival but fail to eradicate the tumor. In addition, the onset of drug resistance and adverse side-effects over time drastically reduce the chances of treatment. We recently showed that Twist1, a transcription factor involved in the epithelial mesenchymal transition (EMT), was strongly upregulated in ATC, and we wondered whether it might represent a therapeutic target in ATC patients. To investigate this hypothesis, the effects of harmine, a ß-carboline alkaloid shown to induce degradation of the Twist1 protein and to possess antitumoral activity in different cancer types, were evaluated on two ATC-derived cell lines, BHT-101 and CAL-62. The results obtained demonstrated that, in both cell lines, harmine reduced the level of Twist1 protein and reverted the EMT, as suggested by the augmentation of E-cadherin and decrease in fibronectin expression. The drug also inhibited cell proliferation and migration in a dose-dependent manner and significantly reduced the anchorage-independent growth of both ATC cell lines. Harmine was also capable of inducing apoptosis in BHT-101 cells, but not in CAL-62 ones. Finally, the activation of PI3K/Akt signaling, but not that of the MAPK, was drastically reduced in treated cells. Overall, these in vitro data suggest that harmine could represent a new therapeutic option for ATC treatment.

Discovery of novel harmine derivatives as GSK-3ß/DYRK1A dual inhibitors for Alzheimer's disease treatment.

Multitarget-directed ligands (MTDLs) have recently attracted significant interest due to their superior effectiveness in multifactorial Alzheimer's disease (AD). Combined inhibition of two important AD targets, glycogen synthase kinase-3ß (GSK-3ß) and dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A), may be a breakthrough in the treatment of AD. Based on our previous work, we have designed and synthesized a series of novel harmine derivatives, investigated their inhibition of GSK-3ß and DYRK1A, and evaluated a variety of biological activities. The results of the experiments showed that most of these compounds exhibited good activity against GSK-3ß and DYRK1A in vitro. ZLQH-5 was selected as the best compound due to the most potent inhibitory effect against GSK-3ß and DYRK1A. Molecular docking studies demonstrated that ZLQH-5 could form stable interactions with the ATP binding pocket of GSK-3ß and DYRK1A. In addition, ZLQH-5 showed low cytotoxicity against SH-SY5Y and HL-7702, good blood-brain barrier permeability, and favorable pharmacokinetic properties. More importantly, ZLQH-5 also attenuated the tau hyperphosphorylation in the okadaic acid SH-SY5Y cell model. These results indicated that ZLQH-5 could be a promising dual-target drug candidate for the treatment of AD.

The ß-Carboline Harmine Has a Protective Immunomodulatory Role in Nonhealing Cutaneous Leishmaniasis.

Cutaneous leishmaniasis affects 1 million people worldwide annually. Although conventional treatments primarily target the parasite, there is growing interest in host immune modulation. In this study, we investigated the impact of synthetic ß-carboline harmine (ACB1801), previously shown to be immunoregulatory in cancer, on the pathology caused by a drug-resistant Leishmania major strain causing persistent cutaneous lesions. Exposure to ACB1801 in vitro had a modest impact on parasite burden within host macrophages. Moreover, it significantly increased major histocompatibility complex II and costimulatory molecule expression on infected dendritic cells, suggesting an enhanced immune response. In vivo, ACB1801 monotherapy led to a substantial reduction in lesion development and parasite burden in infected C57BL/6 mice, comparable with efficacy of amphotericin B. Transcriptomics analysis further supported ACB1801 immunomodulatory effects, revealing an enrichment of TNF-α, IFN-γ, and major histocompatibility complex II antigen presentation signatures in the draining lymph nodes of treated mice. Flow cytometry analysis confirmed an increased frequency (1.5×) of protective CD4+IFN-γ+TNF-α+ T cells and a decreased frequency (2×) in suppressive IL-10+FoxP3- T cells at the site of infection and in draining lymph nodes. In addition, ACB1801 downregulated the aryl hydrocarbon receptor signaling, known to enhance immunosuppressive cytokines. Thus, these results suggest a potential use for ACB1801 alone or in combination therapy for cutaneous leishmaniasis.

Design, synthesis, and biological evaluation of harmine derivatives as topoisomerase I inhibitors for cancer treatment.

A series of ß-carboline derivatives were designed and synthesized by introducing the chalcone moiety into the harmine. The synthesized derivatives were evaluated their anti-proliferative activities against six human cancer cell lines (MCF-7, MDA-MB-231, HepG2, HT29, A549, and PC-3) and one normal cell line (L02). Among them, compound G11 exhibited the potent anti-proliferative activity against MCF-7 cell line, with an IC50 value of 0.34 µM. Further biological studies revealed that compound G11 inhibited colony formation of MCF-7 cells, suppressed MCF-7 cell migration by downregulating migration-associated protein MMP-2. In addition, it could induce apoptosis of MCF-7 cells by downregulating Bcl-2 and upregulating Cleaved-PARP, Bax, and phosphorylated Bim proteins. Furthermore, compound G11 can act as a Topo I inhibitor, affecting DNA synthesis and transcription, thereby inhibiting cancer cell proliferation. Moreover, compound G11 inhibited tumor growth in 4T1 syngeneic transplant mice with an inhibition rate of 43.19 % at a dose of 10 mg/kg, and 63.87 % at 20 mg/kg, without causing significant toxicity to the mice or their organs, achieving the goal of reduced toxicity and increased efficacy. All these results indicate of G11 has enormous potential as an anti-tumor agent and merits further investigation.

Anticancer Potential of ß-Carboline Alkaloids: An Updated Mechanistic Overview.

his comprehensive review is designed to evaluate the anticancer properties of ß-carbolines derived from medicinal plants, with the ultimate goal of assessing their suitability and potential in cancer treatment, management, and prevention. An exhaustive literature survey was conducted on a wide array of ß-carbolines including, but not limited to, harmaline, harmine, harmicine, harman, harmol, harmalol, pinoline, tetrahydroharmine, tryptoline, cordysinin C, cordysinin D, norharmane, and perlolyrine. Various analytical techniques were employed to identify and screen these compounds, followed by a detailed analysis of their anticancer mechanisms. Natural ß-carbolines such as harmaline and harmine have shown promising inhibitory effects on the growth of cancer cells, as evidenced by multiple in vitro and in vivo studies. Synthetically derived ß-carbolines also displayed noteworthy anticancer, neuroprotective, and cognitive-enhancing effects. The current body of research emphasizes the potential of ß-carbolines as a unique source of bioactive compounds for cancer treatment. The diverse range of ß-carbolines derived from medicinal plants can offer valuable insights into the development of new therapeutic strategies for cancer management and prevention.

1,3-Substituted ß-Carboline Derivatives as Potent Chemotherapy for the Treatment of Cystic Echinococcosis.

Echinococcosis is a global public health issue that generally occurs in areas with developed animal husbandry. In search of safe and effective therapeutic agents against echinococcosis, we designed and synthesized new 1,3-substituted ß-carboline derivatives based on harmine. Among them, compounds 1a, 1c, and 1e displayed potent inhibitory activity against Echinococcus granulosus in vitro, significantly better than albendazole and harmine. The morphological detection revealed that 1a, 1c, and 1e significantly changed the ultrastructure of Echinococcus granulosus protoscolices (PSCs). Furthermore, pharmacokinetic studies suggested that 1a possessed a better metabolic property. Encouragingly, 1a exhibited a highest cyst inhibition rate as 76.8% in vivo and did not display neurotoxicity in mice. Further mechanistic research illustrated that 1a has the potential to induce autophagy in PSCs, which may be responsible for the therapeutic effect of the drugs. Together, 1a could be a promising therapeutic agent against echinococcosis, warranting further study.

Harmine and Kaempferol treatment enhances NFATC1 and FOXP3 mediated regulatory T-cells' suppressive capacity in generalized vitiligo.

BACKGROUND: Generalized vitiligo (GV) is an autoimmune disease characterized by the progressive loss of melanocytes. OBJECTIVES: Current study was undertaken to assess in-vitro therapeutic potential of Harmine and Kaempferol for GV. METHODS: Calcium, calcineurin, NFATC1 levels, cell proliferation were assessed by various kits and ORAI1, PEIZO1, Calcineurin, GSK3B, DYRK1A transcripts and IFN-γ,IL-10,TGF-ß protein levels were assessed by qPCR and ELISA in blood and skin biopsy samples from Tregs of 52 patients and 50 controls. RESULTS: Harmine and Kaempferol treatment enhances Treg suppressive capacity, NFATs and FOXP3 expression in blood and skin Tregs of GV patients (p < 0.05). Furthermore, Harmine and Kaempferol treatment in Tregs increased calcineurin and NFATC1 activity and decreased DYRK1A transcripts in blood and skin Tregs of GV patients(p < 0.05). In-silico analysis revealed that Harmine and Kaempferol might boost Treg suppressive capacity by increasing calcineurin dephosphorylation activity leading to increase NFATs activation and also increase nuclear retention of NFATs by inhibiting DYRK1a phosphorylation activity. Moreover, calcineurin and NFATC1 activity in Tregs were positively correlated with Treg suppressive capacity, NFATC1 and FOXP3 expression (p < 0.05), whereas, DYRK1A transcripts were negatively correlated with Treg suppressive capacity, NFATC1 and FOXP3 expression (p < 0.05). These compounds significantly increased melanocytes' survival and proliferation in Treg:CD4+/CD8+:SK-Mel-28 cell line co-culture system from GV patients (p < 0.0001). CONCLUSIONS: For the first time the study suggests that Harmine and Kaempferol treated Tregs could control the CD8+ and CD4+T-cells' proliferation and IFN-γ production, leading to melanocytes' survival and proliferation. These compounds may serve as novel Treg-based therapeutics for GV; however, in vivo studies are warranted to assess the safety and efficacy of these compounds.

In vitro and in vivo Efficacies of Novel Harmine Derivatives in the Treatment of Cystic Echinococcosis.

Introduction: Cystic echinococcosis (CE) is a chronic zoonotic parasitic disease caused by the larvae of the Echinococcus granulosus sensu lato (s.l.) cluster. The current existing drugs have limited therapeutic efficacy against cystic echinococcosis, and thus, there is an urgent need to develop new drugs. Methods: In this study, 7 harmine (HM) derivatives were screened and the effects of HM derivatives on E. granulosus sensu stricto (s.s.) were evaluated by in vitro and mouse experiments. The safety of the HM derivatives was assessed by cytotoxicity assays, acute toxicity study in animals and subacute toxicity study. Results: These results show that the HM derivatives H-2-168 and DH-004 exhibited more significant antiparasitic effects at an initial concentration of 40 µM. The results of further studies showed that H-2-168 and DH-004 had dose-dependent effects against protoscoleces and had satisfactory therapeutic outcomes in vivo. Electron microscopy observations demonstrated that H-2-168 and DH-004 caused severe disruption of the parasite ultrastructure. Notably, the results of the acute toxicity and subchronic toxicity studies showed that H-2-168 and DH-004 had significantly improved safety. In addition, we found that H-2-168 and DH-004 induced DNA damage in E. granulosus s.s., which may be the mechanism by which these drugs produce their therapeutic effects. Discussion: Overall, the data from this work demonstrate that H-2-168 and DH-004 are highly effective candidate compounds with low toxicity for the treatment of CE and will provide a new therapeutic strategy for CE pharmacological treatment.

Mechanistic Insights into Harmine-Mediated Inhibition of Human DNA Methyltransferases and Prostate Cancer Cell Growth.

Mammalian DNA methyltransferases (DNMTs), including DNMT1, DNMT3A, and DNMT3B, are key DNA methylation enzymes and play important roles in gene expression regulation. Dysregulation of DNMTs is linked to various diseases and carcinogenesis, and therefore except for the two approved anticancer azanucleoside drugs, various non-nucleoside DNMT inhibitors have been identified and reported. However, the underlying mechanisms for the inhibitory activity of these non-nucleoside inhibitors still remain largely unknown. Here, we systematically tested and compared the inhibition activities of five non-nucleoside inhibitors toward the three human DNMTs. We found that harmine and nanaomycin A blocked the methyltransferase activity of DNMT3A and DNMT3B more efficiently than resveratrol, EGCG, and RG108. We further determined the crystal structure of harmine in complex with the catalytic domain of the DNMT3B-DNMT3L tetramer revealing that harmine binds at the adenine cavity of the SAM-binding pocket in DNMT3B. Our kinetics assays confirm that harmine competes with SAM to competitively inhibit DNMT3B-3L activity with a Ki of 6.6 µM. Cell-based studies further show that harmine treatment inhibits castration-resistant prostate cancer cell (CRPC) proliferation with an IC50 of ∼14 µM. The CPRC cells treated with harmine resulted in reactivating silenced hypermethylated genes compared to the untreated cells, and harmine cooperated with an androgen antagonist, bicalutamide, to effectively inhibit the proliferation of CRPC cells. Our study thus reveals, for the first time, the inhibitory mechanism of harmine on DNMTs and highlights new strategies for developing novel DNMT inhibitors for cancer treatment.

Discovery of YH677 as a cancer stemness inhibitor that suppresses triple-negative breast cancer growth and metastasis by regulating the TGFß signaling pathway.

Triple-negative breast cancer (TNBC) has a poor prognosis due to the lack of specific and highly effective therapeutic agents. Cancer stem cells (CSCs) are one of the main factors contributing to TNBC relapse and metastasis. Therefore, targeting CSCs selectively with small molecules is a novel strategy for drug development. In this study, the natural product harmine (HM) was identified as a hit compound from 2632 natural product monomers based on phenotypic screening of a 2D assay and patient-derived organoid (PDO) model that was established from a patient who had multiple drug resistance and various visceral and contralateral breast metastases. Next, harmine was further modified and optimized to obtain a lead compound (YH677) with a tetrahydro-ß-carboline scaffold. YH677 showed potent antiproliferative and antimigratory activities against several TNBC cell lines in vitro. In addition, YH677 inhibited epithelial mesenchymal transition (EMT) and stem cell marker expression in a dose-dependent manner. More importantly, YH677 suppressed breast cancer growth and metastasis in orthotopic, metastatic xenograft and patient-derived xenograft (PDX) models in vivo. Mechanistic studies showed that YH677 inhibits the expansion of CSCs by regulating the TGFß/Smad signaling pathway. These preclinical data provide a basis for the development of YH677 as a lead compound for TNBC treatment.

A novel combination of isovanillin, curcumin, and harmine (GZ17-6.02) enhances cell death and alters signaling in actinic keratoses cells when compared to individual components and two-component combinations.

Actinic keratosis is a pre-malignant skin disease caused by excessive exposure to ultraviolet light. The present studies further defined the biology of a novel combination of isovanillin, curcumin, and harmine in actinic keratosis cells in vitro . An oral formulation (GZ17-6.02) and topical preparation (GZ21T) comprised of the same fixed, stoichiometric ratio have been developed. Together, the three active ingredients killed actinic keratosis cells more effectively than any of its component parts as either individual agents or when combined in pairs. The three active ingredients caused greater levels of DNA damage than any of its component parts as either individual agents or when combined in pairs. As a single agent, compared to isolated components, GZ17-6.02/GZ21T caused significantly greater activation of PKR-like endoplasmic reticulum kinase, the AMP-dependent protein kinase, and ULK1 and significantly reduced the activities of mTORC1, AKT, and YAP. Knockdown of the autophagy-regulatory proteins ULK1, Beclin1, or ATG5 significantly reduced the lethality of GZ17-6.02/GZ21T alone. Expression of an activated mammalian target of rapamycin mutant suppressed autophagosome formation and autophagic flux and reduced tumor cell killing. Blockade of both autophagy and death receptor signaling abolished drug-induced actinic keratosis cell death. Our data demonstrate that the unique combination of isovanillin, curcumin, and harmine represents a novel therapeutic with the potential to treat actinic keratosis in a manner different from the individual components or pairs of the components.

Harmine suppresses the malignant phenotypes and PI3K activity in breast cancer.

Breast cancer remains a serious threaten to the women's health, discovery of potent treatment would help to improve the outcomes of breast cancer patients. Harmine extracted from Peganum harmala L , has been reported to exert tumor suppressive activity in several malignancies. Our objective was to demonstrate the effects of harmine on the malignant phenotypes of breast cancer cells. Breast cancer cell lines (MDA-MB-231, SKBR3, and MCF-7) and human normal breast cell line MCF-10A were employed in the present study. The MTT and colony formation assays were applied to the detection of cell viability and proliferation. Wound healing and transwell assays were performed to evaluate the alterations of cell migration and invasion after harmine treatment. Flow cytometry was applied to assess the effect of harmine in inducing cell apoptosis. Furthermore, western blotting assay was used to detect the biomarkers of epithelial-mesenchymal transition and phosphatidylinositol 3 kinase (PI3K) signaling pathway. The tumorigenesis ability was detected by subcutaneous implantation. Harmine dose-dependently suppressed the viability and proliferative capacity of breast cancer cells. Flow cytometry showed that harmine induced apoptosis in MCF-7 and MDA-MB-231 cells. In addition, harmine effectively inhibited the migration and invasion abilities of breast cancer cells. Western blotting indicated harmine significantly promoted E-cadherin and PTEN expression, while suppressed N-cadherin, vimentin, PI3K, p-mTOR, and AKT levels. Interfering the PTEN expression by siRNA partly rescued the activity of PI3K signaling pathway. Moreover, harmine injection also suppressed the tumorigenesis of breast cancer cells. Our results suggested that Hermine could suppress multiple malignant phenotypes and inhibit PI3K signaling, which supports that harmine might be a potential tumor-suppressive natural compound against breast cancer.

The ß-carboline Harmine improves the therapeutic benefit of anti-PD1 in melanoma by increasing the MHC-I-dependent antigen presentation.

Harmine is a dual-specificity tyrosine-regulated kinase 1A (DYRK1A) inhibitor that displays a number of biological and pharmacological properties. Also referred to as ACB1801 molecule, we have previously reported that harmine increases the presentation of major histocompatibility complex (MHC)-I-dependent antigen on melanoma cells. Here, we show that ACB1801 upregulates the mRNA expression of several proteins of the MHC-I such as Transporter Associated with antigen Processing TAP1 and 2, Tapasin and Lmp2 (hereafter referred to as MHC-I signature) in melanoma cells. Treatment of mice bearing melanoma B16-F10 with ACB1801 inhibits the growth and weight of tumors and induces a profound modification of the tumor immune landscape. Strikingly, combining ACB1801 with anti-PD1 significantly improves its therapeutic benefit in B16-F10 melanoma-bearing mice. These results suggest that, by increasing the MHC-I, ACB1801 can be combined with anti-PD1/PD-L1 therapy to improve the survival benefit in cancer patients displaying a defect in MHC-I expression. This is further supported by data showing that i) high expression levels of TAP1, Tapasin and Lmp2 was observed in melanoma patients that respond to anti-PD1; ii) the survival is significantly improved in melanoma patients who express high MHC-I signature relative to those expressing low MHC-I signature; and iii) high expression of MHC-I signature in melanoma patients was correlated with increased expression of CD8 and NK cell markers and overexpression of proinflammatory chemokines involved in the recruitment of CD8+ T cells.

Synthesis, biological evaluation and preliminary mechanisms of 6-amino substituted harmine derivatives as potential antitumor agents.

To explore the effect of the introduction of the amino and substituted amino groups on the antitumor activity of harmine, twenty-five novel 6-amino substituted harmine derivatives (3a-3j and 5a-5o) were synthesized and evaluated for anti-proliferative activity on a panel of cancer cell lines. Compounds 3i and 5n exhibited the most potent antiproliferative activity with IC50 values lower than 2.2 µM. Especially, compound 5n possessed extremely potent antitumor activity with IC50 values of 0.34 µM and 0.65 µM against HL-60 and A549 cell lines, respectively. Further, the preliminary studies of mechanisms showed that compound 5n could significantly induce cell apoptosis in a dose-dependent manner, cause cell cycle arrest at the G2/M phase and intercalate into ct-DNA via the competition with EB, while displaying very weak topoisomerase I (Topo I) inhibition activity. More importantly, 5n showed mild cytotoxicity against human normal lung epithelial cells BEAS-2B. Based on these considerations, 5n may be a good antitumor candidate compound for further exploration.

Enhanced Glioblastoma Selectivity of Harmine via the Albumin Carrier.

Glioblastoma, the most common tumor in the brain, has witnessed very little clinical progress over the last decades. Exploring and discovering new therapeutic strategies for glioblastoma has become a critical problem. Harmine (HM), belonging to the beta-carboline alkaloid, is a natural product and isolated from the seeds of Peganum harmala L., which own notable antitumor activity in vitro. However, the poor water solubility and less selectivity of HM severely limit its clinical use. For enhancing its selective ability to tumor cells, we fabricated a kind of protein nanoparticles (BSA-HM NPs), composed of the modified bovine serum albumin (BSA) and HM. It was substantiated through in vitro and in vivo experiment that BSA-HM NPs could predominantly accumulate in tumor tissues and exhibited remarkably enhanced antitumor efficacy. This study provides a promising strategy to improve the bioavailability and avoid side effects of HM as antitumor agents by choosing BSA as carriers.

[Preparation and effect against cervical cancer invasion in vitro of harmine-loaded photosensitive liposomes].

Despite the development of HPV vaccines and screening programs, cervical cancer is still a serious threat to women's health. Early-stage cervical cancer is mainly treated by surgery. However, considering the serious complications after surgery, hyperthermia is recommended to enhance the effect of chemotherapy, retain the integrity of cervix, improve the treatment effect, which provides a therapeutic basis for the early treatment of cervical cancer. The photosensitive liposomes containing harmine and dye IR-780 were prepared by thin-film dispersion method and separated by Sephadex G-50 dextran gel column. The preparation conditions were optimized as the mass ratio of phospholipid to cholesterol membrane material being 8∶1 and that of drug to lipid being 1∶20. The results of HPLC showed that the encapsulation efficiency of harmine was 55.6%±0.18%. The prepared photosensitive liposomes were round and evenly distributed under transmission electron microscope, with the particle size of(125.2±0.62) nm determined by Marvin particle size analyzer and the Zeta potential of(-2.55±0.76) mV. Additionally, the photosensitive liposomes had the photothermal conversion efficiency, an important property of photothermal agent, of 27.1%±0.86%. The photosensitive liposomes stored at 4 ℃ showed stable encapsulation efficiency in the first 14 days without flocculation. The sulforhodamine B(SRB) assay was employed to determine the inhibitory effect of the liposomes on the proliferation of HeLa cells under near-infrared(NIR) irradiation or not, which showcased stronger inhibitory effect under NIR irradiation. The results of Transwell assay indicated that the prepared liposomes significantly inhibited the invasion and migration of HeLa cells in vitro. The findings of this study provide a basis for the treatment of cervical cancer with harmine.