Fangchinoline derivatives induce cell cycle arrest and apoptosis in human leukemia cell lines via suppression of the PI3K/AKT and MAPK signaling pathway

Fabrication of bimetallic Ag@ZnO nanocomposite and its anti-cancer activity on cervical cancer via impeding PI3K/AKT/mTOR pathway

INTRODUCTION

Bimetallic nanoparticles, specifically Zinc oxide (ZnO) and Silver (Ag), continue to much outperform other nanoparticles investigated for a variety of biological uses in the field of cancer therapy. This study introduces biosynthesis of bimetallic silver/zinc oxide nanocomposites (Ag@ZnO NCs) using the Crocus sativus extract and evaluates their anti-cancer properties against cervical cancer.

METHODS

The process of generating bimetallic nanoparticles (NPs), namely Ag@ZnO NCs, through the utilization of Crocus sativus extract proved to be uncomplicated and eco-friendly. Various methods, such as UV-vis, DLS, FTIR, EDX, and SEM analyses, were utilized to characterize the generated Ag@ZnO NCs. The MTT assay was employed to assess the cytotoxic properties of biosynthesized bimetallic Ag@ZnO NCs against the HeLa cervical cancer cell line. Moreover, the impact of Ag@ZnO NCs on HeLa cells was assessed by examining cell survival, ROS production, MMP levels, and induced apoptosis. Through western blot analysis, the expression levels of the PI3K, AKT, mTOR, Cyclin D, and CDK proteins seemed to be ascertained. Using flow cytometry, the cancer cells' progression through necrosis and apoptosis, in addition to the cell cycle analysis, were investigated.

RESULTS

Bimetallic Ag@ZnO NCs that were biosynthesized showed a high degree of stability, as demonstrated by the physicochemical assessments. The median size of the particles in these NCs was approximately 80-90 nm, and their zeta potential was -14.70 mV. AgNPs and ZnO were found, according to EDX data. Further, Ag@ZnO NCs hold promise as a potential treatment for cervical cancer. After 24 hours of treatment, a dosage of 5 µg/mL or higher resulted in a maximum inhibitory effect of 58 ± 2.9. The concurrent application of Ag/ZnO NPs to HeLa cells resulted in elevated apoptotic signals and a significant generation of reactive oxygen species (ROS). As a result, the bimettalic Ag@ZnO NCs treatment has been recognized as a chemotherapeutic intervention by inhibiting the production of PI3K, AKT, and mTOR-mediated regulation of propagation and cell cycle-regulating proteins.

CONCLUSIONS

The research yielded important insights into the cytotoxic etiology of biosynthesized bimetallic Ag@ZnO NCs against HeLa cells. The biosynthesized bimetallic Ag@ZnO NCs have a significant antitumor potential, which appears to be associated with the development of oxidative stress, which inhibits the development of the cell cycle and the proliferation of cells. Therefore, in the future, biosynthesized bimetallic Ag@ZnO NCs may be used as a powerful anticancer drug to treat cervical cancer.

Fangji Fuling Decoction Alleviates Sepsis by Blocking MAPK14/FOXO3A Signaling Pathway

OBJECTIVE

To examine the therapeutic effect of Fangji Fuling Decoction (FFD) on sepsis through network pharmacological analysis combined with in vitro and in vivo experiments.

METHODS

A sepsis mouse model was constructed through intraperitoneal injection of 20 mg/kg lipopolysaccharide (LPS). RAW264.7 cells were stimulated by 250 ng/mL LPS to establish an in vitro cell model. Network pharmacology analysis identified the key molecular pathway associated with FFD in sepsis. Through ectopic expression and depletion experiments, the effect of FFD on multiple organ damage in septic mice, as well as on cell proliferation and apoptosis in relation to the mitogen-activated protein kinase 14/Forkhead Box O 3A (MAPK14/FOXO3A) signaling pathway, was analyzed.

RESULTS

FFD reduced organ damage and inflammation in LPS-induced septic mice and suppressed LPS-induced macrophage apoptosis and inflammation in vitro (P<0.05). Network pharmacology analysis showed that FFD could regulate the MAPK14/FOXO signaling pathway during sepsis. As confirmed by in vitro cell experiments, FFD inhibited the MAPK14 signaling pathway or FOXO3A expression to relieve LPS-induced macrophage apoptosis and inflammation (P<0.05). Furthermore, FFD inhibited the MAPK14/FOXO3A signaling pathway to inhibit LPS-induced macrophage apoptosis in the lung tissue of septic mice (P<0.05).

CONCLUSION

FFD could ameliorate the LPS-induced inflammatory response in septic mice by inhibiting the MAPK14/FOXO3A signaling pathway.

Calothrixin B derivatives induce apoptosis and cell cycle arrest on HEL cells through the ERK/Ras/Raf/MEK pathway

BACKGROUND

Acute erythroleukemia (AEL) is acute myeloid leukemia characterized by malignant erythroid proliferation. AEL has a low survival rate, which has seriously threatened the health of older adults. Calothrixin B is a carbazole alkaloid isolated from the cyanobacteria Calothrix and exhibits anti-cancer activity. To discover more potential anti-erythroleukemia compounds, we used calothrixin B as the structural skeleton to synthesize a series of new compounds.

METHODS

In the cell culture model, we evaluated apoptosis and cell cycle arrest using MTT assay, flow cytometry analysis, JC-1 staining, Hoechst 33258 staining, and Western blot. Additionally, assessing the curative effect in the animal model included observation of the spleen, HE staining, flow cytometry analysis, and detection of serum biochemical indexes.

RESULTS

Among the Calothrixin B derivatives, H-107 had the best activity against leukemic cell lines. H-107 significantly inhibited the proliferation of HEL cells with an IC50 value of 3.63 ± 0.33 μM. H-107 induced apoptosis of HEL cells by damaging mitochondria and activating the caspase cascade and arrested HEL cells in the G0/G1 phase. Furthermore, H-107 downregulated the protein levels Ras, p-Raf, p-MEK, p-ERK and c-Myc. Pretreatment with ERK inhibitor (U0126) increased H-107-induced apoptosis. Thus, H-107 inhibited the proliferation of HEL cells by the ERK /Ras/Raf/MEK signal pathways. Interestingly, H-107 promoted erythroid differentiation into the maturation of erythrocytes and effectively activated the immune cells in erythroleukemia mice.

CONCLUSION

Overall, our findings suggest that H-107 can potentially be a novel chemotherapy for erythroleukemia.

Angelicin inhibits cell growth and promotes apoptosis in oral squamous cell carcinoma by negatively regulating DUSP6/cMYC signaling pathway

Angelicin has been reported to have antitumor effects on many types of cancer. However, few studies on angelicin in oral squamous cell carcinoma (OSCC) have been performed. We performed cell cycle and apoptosis analyses to assess the effect of angelicin on OSCC cells. We conducted RNA-seq studies to reveal differentially expressed genes (DEGs). Dual-specificity phosphatase 6 (DUSP6) and c-MYC were strongly down-regulated differential genes. Silencing RNA (siRNA) was used to knockdown DUSP6. The mouse xenograft model was used to mimic OSCC. Angelicin inhibited OSCC in vitro. We found that DUSP6 interacted with c-MYC. DUSP6 knockdown group and DUSP6 knockdown + angelicin group had similar effects of OSCC cells. Angelicin could reduce tumor formation, DUSP6, and c-MYC expression in vivo. Compared with paclitaxel, the tumor inhibition effect of the two drugs was similar. However, angelicin did not cause weight loss and had lower toxicity. In sum, Angelicin has antitumor effects on OSCC in vitro and vivo by negatively regulating the DUSP6 mediated c-MYC signaling pathway.

Fangchinoline derivatives inhibits PI3K signaling in vitro and in vivo in non-small cell lung cancer

Fangchinoline (Fan) are extracted from the traditional Chinese medicine Stephania tetrandra S., which is a bis-benzyl isoquinoline alkaloids with anti-tumor activity. Therefore, 25 novel Fan derivatives have been synthesized and evaluated for their anti-cancer activity. In CCK-8 assay, these fangchinoline derivatives displayed higher proliferation inhibitory activity on six tumor cell lines than the parental compound. Compared to the parent Fan, compound 2h presented the anticancer activity against most cancer cells, especially A549 cells, with an IC50 value of 0.26 μM, which was 36.38-fold, and 10.61-fold more active than Fan and HCPT, respectively. Encouragingly, compound 2h showed low biotoxicity to the human normal epithelial cell BEAS-2b with an IC50 value of 27.05 μM. The results indicated compound 2h remarkably inhibited the cell migration by decreasing MMP-2 and MMP-9 expression and inhibited the proliferation of A549 cells by arresting the G2/M cell cycle. Meanwhile, compound 2h could also induce A549 cell apoptosis by promoting endogenous pathways of mitochondrial regulation. In nude mice presented that the growth of tumor tissues was markedly inhibited by the consumption of compound 2h in a dose-dependent manner, and it was found that compound 2h could inhibit the mTOR/PI3K/AKT pathway in vivo. In docking analysis, high affinity interaction between 2h and PI3K was responsible for drastic kinase inhibition by the compound. To conclude, this derivative compound may be useful as a potent anti-cancer agent for treatment of NSCLC.

Tribulus terrestris L. extract ameliorates atherosclerosis by inhibition of vascular smooth muscle cell proliferation in ApoE-/- mice and A7r5 cells via suppression of Akt/MEK/ERK signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS) is one of major threatens of death worldwide, and vascular smooth muscle cell (VSMC) proliferation is an important characteristic in the progression of AS. Tribulus terrestris L. is a well-known Chinese Materia Medica for treating skin pruritus, vertigo and cardiovascular diseases in traditional Chinese medicine. However, its anti-AS activity and inhibition effect on VSMC proliferation are not fully elucidated.

AIMS

We hypothesize that the furostanol saponins enriched extract (FSEE) of T. terrestris L. presents anti-AS effect by inhibition of VSMC proliferation. The molecular action mechanism underlying the anti-VSMC proliferation effect of FSEE is also investigated.

MATERIALS AND METHODS

Apolipoprotein-E deficient (ApoE^-/-) mice and rat thoracic smooth muscle cell A7r5 were employed as the in vivo and in vitro models respectively to evaluate the anti- AS and VSMC proliferation effects of FSEE. In ApoE^-/- mice, the amounts of total cholesterol, triglyceride, low density lipoprotein and high density lipoprotein in serum were measured by commercially available kits. The size of atherosclerotic plaque was observed by hematoxylin & eosin staining. The protein expressions of α-smooth muscle actin (α-SMA) and osteopontin (OPN) in the plaque were examined by immunohistochemistry. In A7r5 cells, the cell viability and proliferation were tested by MTT and Real Time Cell Analysis assays. The cell migration was evaluated by wound healing assay. Propidium iodide staining followed by flow cytometry was used to analyze the cell cycle progression. The expression of intracellular total and phosphorylated proteins including protein kinase B (Akt) and mitogen-activated protein kinases (MAPKs), such as mitogen-activated extracellular signal-regulated kinase (MEK), extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), were detected by western blotting analysis.

RESULTS

FSEE significantly reduced the area of atherosclerotic plaque in high-fat diet-fed ApoE^-/- mice. And FSEE increased the protein expression level of α-SMA and decreased the level of OPN in atherosclerotic plaque, which revealed the inhibition of VSMC phenotype switching and proliferation. In A7r5 cells, FSEE suppressed fetal bovine serum (FBS) or oxidized low density lipoprotein (oxLDL)-triggered VSMC proliferation and migration in a concentration dependent manner. FSEE protected against the elevation of cell numbers in S phase induced by FBS or oxLDL and the reduction of cell numbers in G₀/G₁ phase induced by oxLDL. Moreover, the phosphorylation of Akt and MAPKs including MEK, ERK and JNK could be facilitated by FBS or oxLDL, while co-treatment of FSEE attenuated the phosphorylation of Akt induced by oxLDL as well as the phosphorylation of MEK and ERK induced by FBS. In addition, (25R)-terrestrinin B (JL-6), which was the main ingredient of FSEE, and its potential active pharmaceutical ingredients tigogenin (Tigo) and hecogenin (Heco) also significantly attenuated FBS or oxLDL-induced VSMC proliferation in A7r5 cells.

CONCLUSION

FSEE presents potent anti- AS and VSMC proliferation activities and the underlying mechanism is likely to the suppression of Akt/MEK/ERK signaling. The active components of FSEE are JL-6 and its potential active pharmaceutical ingredients Tigo and Heco. So, FSEE and its active compounds may be potential therapeutic drug candidates for AS.

Fangchinoline inhibits non-small cell lung cancer metastasis by reversing epithelial-mesenchymal transition and suppressing the cytosolic ROS-related Akt-mTOR signaling pathway

Few drugs alleviate non-small cell lung cancer (NSCLC) metastasis effectively. Small molecular screening demonstrated that fangchinoline (Fan) reversed epithelial-mesenchymal transition (EMT) in NSCLC cells, inhibiting cell invasion and migration. RNA sequencing (RNA-seq) of Fan-treated NSCLC cells revealed that Fan potently quenched the NADP⁺ metabolic process. Molecular docking analysis revealed that Fan directly and specifically targeted NOX4. NOX4 was associated with poor prognosis in NSCLC in both The Cancer Genome Atlas (TCGA) and Hong Kong cohorts. In mitochondrial DNA-depleted ρ⁰ NSCLC cells, Fan decreased cytosolic reactive oxygen species (ROS) to inhibit the Akt-mTOR signaling pathway by directly promoting NOX4 degradation. In TCGA and Hong Kong cohorts, NOX4 upregulation acted as a driver event as it positively correlated with metastasis and oxidative stress. Single-cell RNA-seq indicated that NOX4 was overexpressed, especially in cancer cells, cancer stem cells, and endothelial cells. In mice, Fan significantly impeded subcutaneous xenograft formation and reduced metastatic nodule numbers in mouse lung and liver. Drug sensitivity testing demonstrated that Fan suppressed patient-derived organoid growth dose-dependently. Fan is a potent small molecule for alleviating NSCLC metastasis by directly targeting NOX4 and is a potential novel therapeutic agent.

Fangchinoline induces gallbladder cancer cell apoptosis by suppressing PI3K/Akt/XIAP axis

Gallbladder cancer (GBC) is the most common biliary tract malignancy with a dismal prognosis. The development of new drugs may help to improve prognosis. This study found that fangchinoline, a bisbenzylisoquinoline alkaloids, inhibited the proliferation and clone formation of GBC cells in a dose-dependent manner. Moreover, Hoechst staining, TUNEL assays, and flow cytometry demonstrated that fangchinoline effectively induced apoptosis in GBC cells. Further studies found that an anti-apoptotic pathway, the PI3K/Akt/XIAP axis, was significantly inhibited in GBC cells after treating with fangchinoline. Finally, we confirmed that fangchinoline restrained xenograft tumor growth in vivo. Our findings indicate that fangchinoline can be considered a potential drug for GBC treatment.

Recent developments in mitogen activated protein kinase inhibitors as potential anticancer agents

The mitogen activated protein kinase (MAPK) belongs to group of kinase that links the extracellular stimuli to intracellular response. The MAPK signalling pathway (RAS-RAF-MEK-ERK) involved in different pathological conditions like cancer, caused due to genetic or any other factor such as physical or environmental. Many studies have been conducted on the pathological view of MAPK cascade and its associated element like RAS, RAF, MEK, ERK or its isoforms, and still the research is going on particularly with respect to its activation, regulation and inhibition. The MAPK signalling pathway has become the area of research to identify new target for the management of cancer. A number of heterocyclics are key to fight with the cancer associated with these enzymes thus give some hope in the management of cancer by inhibiting MAPK cascade. In the present article, we have focussed on MAPK signalling pathway and role of different heterocyclic scaffolds bearing nitrogen, sulphur and oxygen and about their potential to block MAPK signalling pathway. The heterocyclics are gaining importance due to high potency and selectivity with less off-target effects against different targets involved in the MAPK signalling pathway. We have tried to cover recent advancements in the MAPK signalling pathway inhibitors with an aim to get better understanding of the mechanism of action of the compounds. Several compounds in the preclinical and clinical studies have been thoroughly dealt with. In addition to the synthetic compounds, a significant number of natural products containing heterocyclic moieties as MAPK signalling pathway inhibitors have been put together. The structure activity relationship along with docking studies have been discussed to apprehend the mechanistic studies of various compounds that will ultimately help to design and develop more MAPK signalling pathway inhibitors.

Discovery of penipanoid C-inspired 2-(3,4,5-trimethoxybenzoyl)quinazolin-4(3H)-one derivatives as potential anticancer agents by inhibiting cell proliferation and inducing apoptosis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common form of liver cancer and the fourth leading cause of cancer-related death worldwide. First-line drugs such as sorafenib provide only a modest benefit to HCC patients. In this study, the gram-scale synthesis of 2-benzoylquinazolin-4(3H)-one skeleton was achieved successfully via the I₂/DMSO catalytic system. A series of penipanoid C-inspired 2-(3,4,5-trimethoxybenzoyl)quinazolin-4(3H)-one derivatives was synthesized and evaluated for their cytotoxic activities against four cancer cell lines, HepG2, Bel-7402, A549, and U251. Among these compounds, 4a was the most effective one with IC₅₀ values of 1.22 μM and 1.71 μM against HepG2 and Bel-7402 cells, respectively. Mechanistic studies showed that 4a inhibited hepatocellular carcinoma cell proliferation via arresting cell cycle. Additionally, 4a induced HepG2 cells apoptosis by inducing reactive oxygen species production and elevating the expression of apoptosis-related proteins. More importantly, 4a displayed significant in vivo anticancer effects in the HepG2 xenograft models. This suggests that 4a is a promising lead compound with the potential to be developed as a chemotherapy agent for hepatocellular carcinoma.

QTMP, a Novel Thiourea Polymer, Causes DNA Damage to Exert Anticancer Activity and Overcome Multidrug Resistance in Colorectal Cancer Cells

Colorectal cancer (CRC) is one of the most common malignancies, and multidrug resistance (MDR) severely restricts the effectiveness of various anticancer drugs. Therefore, the development of novel anticancer drugs for the treatment of CRC patients with MDR is necessary. Quaternized thiourea main-chain polymer (QTMP) is a self-assembled nanoparticle with good water solubility. Notably, QTMP is not a P-glycoprotein (P-gp) substrate, and it exhibits potent cytotoxic activity against CRC cells, including HCT116/DDP and P-gp-mediated multidrug-resistant Caco2 cells. QTMP also exhibits a strong anticancer activity against SW480 cells in vivo. Interestingly, reactive oxygen species (ROS) and reactive nitrogen species (RNS) production were increased in a concentration-dependent manner in QTMP-treated HCT116, SW480 and Caco2 cells. Importantly, QTMP causes DNA damage in these CRC cells via direct insertion into the DNA or regulation of ROS and/or RNS production. QTMP also induces caspase-dependent apoptosis via overproduction of ROS and RNS. Therefore, QTMP is a promising anticancer therapeutic agent for patients with CRC, including those cancer cells with P-gp-mediated MDR. The present study also indicates that the design and synthesis of anticancer drugs based on thiourea polymers is promising and valuable, thereby offering a new strategy to address MDR, and provides reference resources for further investigations of thiourea polymers.

Bag-1L Protects against Cell Apoptosis in an In Vitro Model of Lung Ischemia-Reperfusion Injury through the C-Terminal "Bag" Domain

Bcl-2-associated athanogene 1 (Bag-1) is a multifunctional and antiapoptotic protein that binds to the antiapoptosis regulator Bcl-2 and promotes cell survival. To investigate the protective function of Bag-1, we examined the effects of Bag-1L, one isoform of Bag-1, in an in vitro cell culture model of lung ischemia-reperfusion injury (LIRI) generated by treatment of A549 cells with hypoxia/reoxygenation. Overexpression of full-length Bag-1L increased the viability of A549 cells and reduced cell apoptosis in response to 6 h of hypoxia/reoxygenation treatment. Furthermore, Bag-1L overexpression enhanced the heat shock protein 70 (HSP70) and Bcl-2 protein levels, increased the phosphorylation of AKT, decreased Bax and cleaved caspase-3 levels, and was able to overcome cell cycle arrest. These effects were not observed in A549 cells overexpressing a truncated form of Bag-1L lacking the "Bag domain," denoted Bag-1L△C. The "Bag domain" is the C-terminal 47 amino acids. Taken together, the results of this study suggest that Bag-1L overexpression can protect against oxidative stress and apoptosis in an in vitro LIRI model, with a dependence on the Bag domain.

Discovery and synthesis of rocaglaol derivatives inducing apoptosis in HCT116 cells via suppression of MAPK signaling pathway

Six rocaglaol derivatives were isolated from Dysoxylum gotadhora, and those compounds showed good cytotoxic activity with IC₅₀ values ranging from 10 to 350 ng/mL against five different cancer cells. Obviously, further total synthesis of rocaglaol derivatives for medical chemistry study is of great significance. Then, twenty six rocaglaol derivatives including 25 new compounds were designed, synthesized, and evaluated for their cytotoxic activities against three human cancer cell lines: human colon cancer cells (HCT116), colorectal cancer stem cells (P6C), and human red leukocyte leukemia cells (HEL), using MTT assay. Most of derivatives showed good cytotoxic activities, with the lowest IC₅₀ being 3.2 nM for HEL cells, which was 169 times stronger than that of the positive control (doxorubicin). Further mechanism study indicated that 11k could significantly suppress MAPK pathway in HCT116 cells, which may responsible for induction of apoptosis and cell cycle arrest.

Fangchinoline exerts anticancer effects on colorectal cancer by inducing autophagy via regulation AMPK/mTOR/ULK1 pathway

Autophagy has become a promising target for cancer therapy. Fangchinoline (Fan) has been shown to exert anticancer effects in some types of cancers. However, the anticancer effects on colorectal cancer (CRC) and the underlying mechanisms have never been elucidated. More specifically, regulation of autophagy in CRC by Fan has never been reported before. In the present study, Fan was found to induce apoptosis and autophagic flux in the CRC cell lines HT29 and HCT116, which was reflected by the enhanced levels of LC3-II protein and p62 degradation, and the increased formation of autophagosomes and puncta formation by LC3-II. Meanwhile, combination with the early-stage autophagy inhibitor 3-methyladenine (3-MA) but not the late-stage autophagy inhibitor chloroquine (CQ) further increased Fan-induced cell death, which suggested the cytoprotective function of autophagy induced by Fan in both HT29 and HCT116 cells. Moreover, Fan treatment demonstrated a dose- and time-dependently increase in the phosphorylation of AMPK and decrease in the phosphorylation of mammalian target of rapamycin (mTOR) and ULK1, leading to the activation of the AMPK/mTOR/ULK1 signaling pathway. Furthermore, in the HT29 xenograft model, Fan inhibited tumor growth in vivo. These results indicate that Fan inhibited CRC cell growth both in vitro and in vivo and revealed a new molecular mechanism involved in the anticancer effect of Fan on CRC, suggesting that Fan is a potent autophagy inducer and might be a promising anticancer agent.

An overview on the chemistry, pharmacology and anticancer properties of tetrandrine and fangchinoline (alkaloids) from Stephania tetrandra roots

Tetrandrine (TET) and fangchinoline (FAN) are dominant bisbenzylisoquinoline (BBIQ) alkaloids from the roots of Stephania tetrandra of the family Menispermaceae. BBIQ alkaloids comprise two benzylisoquinoline units linked by oxygen bridges. The molecular structures of TET and FAN are exactly the same, except that TET has a methoxy (-OCH₃) group, while FAN has a hydroxyl (-OH) group at C7. In this overview, the current knowledge on the chemistry, pharmacology and anticancer properties of TET and FAN have been updated. The focus is on colon and breast cancer cells, because they are most susceptible to TET and FAN, respectively. Against colon cancer cells, TET inhibits cell proliferation and tumor growth by inducing apoptosis and G1 cell cycle arrest, and suppresses adhesion, migration and invasion of cells. Against breast cancer cells, FAN inhibits cell proliferation by inducing apoptosis, G1-phase cell cycle arrest and inhibits cell migration. The processes involve various molecular mechanisms and signaling pathways. Some insights on the ability of TET and FAN to reverse multi-drug resistance in cancer cells and suggestions for future research are provided.

Design, synthesis and in vitro anticancer research of novel tetrandrine and fangchinoline derivatives

Cancer treatment is one of the major public health issues in the world. Tetrandrine (Tet) and fangchinoline (d-Tet) are two bis-benzyl isoquinoline alkaloids extracted from Stephania tetrandra S. Moore, and their antitumor activities have been confirmed. However, the effective dose of Tet and d-Tet were much higher than that of the positive control and failed to meet clinical standards. Therefore, in this study, as a continuation of our previous work to study and develop high-efficiency and low-toxic anti-tumor lead compounds, twenty new Tet and d-Tet derivatives were designed, synthesized and evaluated as antitumor agents against six cancer cell lines (H460, H520, HeLa, HepG-2, MCF-7, SW480 cell lines) and BEAS-2B normal cells by CCK-8 analysis. Ten derivatives showed better cytotoxic effects than the parent fangchinoline, of which 4g showed the strongest cell growth inhibitory activity with an IC₅₀ value of 0.59 μM against A549 cells. Subsequently, the antitumor mechanism of 4g was studied by flow cytometry, Hoechst 33258, JC-1 staining, cell scratch, transwell migration, and Western blotting assays. These results showed that compound 4g could inhibit A549 cell proliferation by arresting the G2/M cell cycle and inhibiting cell migration and invasion by reducing MMP-2 and MMP-9 expression. Meanwhile, 4g could induce apoptosis of A549 cells through the intrinsic pathway regulated by mitochondria. In addition, compound 4g inhibited the phosphorylation of PI3K, Akt and mTOR, suggesting a correlation between blocking the PI3K/Akt/mTOR pathway and the above antitumor activities. These results suggest that compound 4g may be a future drug for the development of new potential drug candidates against lung cancer.

Design, synthesis and biological evaluation of novel thiosemicarbazone-indole derivatives targeting prostate cancer cells

To discover novel anticancer agents with potent and low toxicity, we designed and synthesized a range of new thiosemicarbazone-indole analogues based on lead compound 4 we reported previously. Most compounds displayed moderate to high anticancer activities against five tested tumor cells (PC3, EC109, DU-145, MGC803, MCF-7). Specifically, the represented compound 16f possessed strong antiproliferative potency and high selectivity toward PC3 cells with the IC₅₀ value of 0.054 μM, compared with normal WPMY-1 cells with the IC₅₀ value of 19.470 μM. Preliminary mechanism research indicated that compound 16f could significantly suppress prostate cancer cells (PC3, DU-145) growth and colony formation in a dose-dependent manner. Besides, derivative 16f induced G1/S cycle arrest and apoptosis, which may be related to ROS accumulation due to the activation of MAPK signaling pathway. Furthermore, molecule 16f could effectively inhibit tumor growth through a xenograft model bearing PC3 cells and had no evident toxicity in vivo. Overall, based on the biological activity evaluation, analogue 16f can be viewed as a potential lead compound for further development of novel anti-prostate cancer drug.

Design, Synthesis of Novel Tetrandrine-14-l-Amino Acid and Tetrandrine-14-l-Amino Acid-Urea Derivatives as Potential Anti-Cancer Agents

Tetrandrine, a dibenzyltetrahydroisoquinoline alkaloid isolated from the root of the traditional Chinese medicinal plant Stephania tetrandra S. Moore, a member of the Menispermaceae, showed anti-cancer activity by inhibiting cell proliferation, preventing cell cycle progress and induction of cell death and autophagy. In this study, twelve tetrandrine-l-amino acid derivatives and twelve tetrandrine-14-l-amino acid-urea derivatives were designed and synthesized, using C14-aminotetrandrine as raw material. Then the preliminary in vitro anti-cancer activities of these derivatives against human breast cancer cell line MDA-MB-231, human leukemia cell lines HEL and K562 were evaluated. The in vitro cytotoxicity results showed that these derivatives exhibited potent inhibitory effects on cancer cell growth, and the primary structure-activity relationships were evaluated. Notably, compound 3f exhibited satisfactory anticancer activity against all three cancer cell lines, especially the HEL cell line, with the IC₅₀ value of 0.23 µM. Further research showed that 3f could induce G1/S cycle arrest and apoptosis in a dose- and time- dependent manner on the leukemia cell line HEL. The results suggested that 3f may be used as a potential anti-cancer agent for human leukemia.