Selective inhibition of HDAC6 by N-acylhydrazone derivative reduces the proliferation and induces senescence in carcinoma hepatocellular cells.

Hepatocellular carcinoma (HCC) is a significant contributor to cancer-related deaths globally. Systemic therapy is the only treatment option for HCC at an advanced stage, with limited therapeutic response. In this study, we evaluated the antitumor potential of four N-acylhydrazone (NAH) derivatives, namely LASSBio-1909, 1911, 1935, and 1936, on HCC cell lines. We have previously demonstrated that the aforementioned NAH derivatives selectively inhibit histone deacetylase 6 (HDAC6) in lung cancer cells, but their effects on HCC cells have not been explored. Thus, the present study aimed to evaluate the effects of NAH derivatives on the proliferative behavior of HCC cells. LASSBio-1911 was the most cytotoxic compound against HCC cells, however its effects were minimal on normal cells. Our results showed that LASSBio-1911 inhibited HDAC6 in HCC cells leading to cell cycle arrest and decreased cell proliferation. There was also an increase in the frequency of cells in mitosis onset, which was associated with disturbing mitotic spindle formation. These events were accompanied by elevated levels of CDKN1A mRNA, accumulation of CCNB1 protein, and sustained ERK1 phosphorylation. Furthermore, LASSBio-1911 induced DNA damage, resulting in senescence and/or apoptosis. Our findings indicate that selective inhibition of HDAC6 may provide an effective therapeutic strategy for the treatment of advanced HCC, including tumor subtypes with integrated viral genome. Further, in vivo studies are required to validate the antitumor effect of LASSBio-1911 on liver cancer.

Piperine-Chlorogenic Acid Hybrid Inhibits the Proliferation of the SK-MEL-147 Melanoma Cells by Modulating Mitotic Kinases.

Melanoma is considered the most aggressive form of skin cancer, showing high metastatic potential and persistent high mortality rates despite the introduction of immunotherapy and targeted therapies. Thus, it is important to identify new drug candidates for melanoma. The design of hybrid molecules, with different pharmacophore fragments combined in the same scaffold, is an interesting strategy for obtaining new multi-target and more effective anticancer drugs. We designed nine hybrid compounds bearing piperine and chlorogenic acid pharmacophoric groups and evaluated their antitumoral potential on melanoma cells with distinct mutational profiles SK-MEL-147, CHL-1 and WM1366. We identified the compound named PQM-277 (3a) to be the most cytotoxic one, inhibiting mitosis progression and promoting an accumulation of cells in pro-metaphase and metaphase by altering the expression of genes that govern G2/M transition and mitosis onset. Compound 3a downregulated FOXM1, CCNB1, CDK1, AURKA, AURKB, and PLK1, and upregulated CDKN1A. Molecular docking showed that 3a could interact with the CUL1-RBX1 complex, which activity is necessary to trigger molecular events essential for FOXM1 transactivation and, in turn, G2/M gene expression. In addition, compound 3a effectively induced apoptosis by increasing BAX/BCL2 ratio. Our findings demonstrate that 3a is an important antitumor candidate prototype and support further investigations to evaluate its potential for melanoma treatment, especially for refractory cases to BRAF/MEK inhibitors.

Synthesis and Structure-Activity Relationship Studies of Novel Aryl Sulfonamides and Their Activity against Human Breast Cancer Cell Lines.

A series of structural analogs of aryl sulfonamide hybrid compounds were synthesised and their cytotoxic activity was evaluated against three human breast cancer cell lines (MCF-7, MDA-MB-231 and Hs 578T). The compounds were designed through electronic, hydrophobic and steric modifications using the chemical structure of N-{4-[(2-hydroxy-3-methoxy-5-propylphenyl)sulfamoyl]phenyl}acetamide (referred to as compound 7) as a starting point to then assess a structure-activity relationship (SAR) study. From the data generated, we observed that compounds 9, 10 and 11 (which have modifications in the substituents of the aryl sulfonamide), efficiently reduced the cell viability of MCF-7 and MDA-MB-231 cell cultures. Based on initial data, we selected compounds 10 and 11 for further investigations into their antiproliferative and/or cytotoxic profile against MDA-MB-231 cells, and we noted that compound 10 was the most promising compound in the series. Compound 10 promoted morphological changes and altered the dynamics of cell cycle progression in MDA-MB-231 cells, inducing arrest in G1/S transition. Taken together, these results show that the dihydroeugenol-aryl-sulfonamide hybrid compound 10 (which has an electron withdrawing nitro group) displays promising antiproliferative activity against MDA-MB-231 cell lines.

A tetraprenylated benzophenone 7-epiclusianone induces cell cycle arrest at G1/S transition by modulating critical regulators of cell cycle in breast cancer cell lines.

Breast cancer is a complex disease and encompassing different types of tumor. Although advances in understanding of the molecular bases of breast cancer biology, the therapeutic proposals available still are not effective. In this scenario, the present study aimed to evaluate the mechanisms associated to antitumor activity of 7-Epiclusianone (7-Epi), a tetraprenylated benzophenone, on luminal A (MCF-7) and claudin-low (Hs 578T) breast cancer cell lines. We found that 7-Epi efficiently inhibited cell proliferation and migration of these cells; however MCF-7 was slightly more responsive than Hs 578T. Cell cycle analysis showed accumulation of cells at G0/G1 phase with drastic reduction of S population in treated cultures. This effect was associated to downregulation of CDKN1A (p21) and cyclin E in both cell lines. In addition, 7-Epi reduced cyclin D1 and p-ERK expression levels in MCF-7 cell line. Cytotoxic effect of 7-Epi on breast cancer cell lines was associated to its ability to increase BAX/BCL-2 ratio. In conclusion, our findings showed that 7-Epi is a promising antitumor agent against breast cancer by modulating critical regulators of the cell cycle and apoptosis.

Phenylpropanoid-based sulfonamide promotes cyclin D1 and cyclin E down-regulation and induces cell cycle arrest at G1/S transition in estrogen positive MCF-7 cell line.

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine. Different biological effects have been reported for sulfonamide-based compounds including antibacterial, antifungal, and antitumor activities. Herein, a series of phenylpropanoid-based sulfonamides (4a, 4a', 4b, 4b', 5a, 5a', 5b and 5b') were synthesized and their cytotoxic activity was evaluated against four cell lines derived from human tumours (A549 - lung, MCF-7 - breast, Hep G2 - hepatocellular carcinoma, and HT-144-melanoma). Cell viability was significantly reduced in the MCF-7 cell line when compounds 4b, 4b' and 5a were used; IC50 values were lower than those found for their precursors (eugenol and dihydroeugenol) and sulfanilamide. We observed that 4b induced cell cycle arrest at G1/S transition. This is probably due to its ability to reduce cyclin D1 and cyclin E expression. Moreover, 4b also induced apoptosis in MCF-7 cells as demonstrated by an increase in the cell population positive for annexin V in treated cultures in comparison to the control group. Taken together, the data showed that 4b is a promising antitumor agent and it should be considered for further in vivo studies.

Calein C, a Sesquiterpene Lactone Isolated From Calea Pinnatifida (Asteraceae), Inhibits Mitotic Progression and Induces Apoptosis in MCF-7 Cells.

Breast cancer is the most common cancer in women worldwide. Estrogen receptor-positive (ER+) breast cancer represents approximately 75% of diagnosed cases, while 15-20% of them are triple-negative (TN). Although there have been improvements in the therapeutic approach, the mortality rate remains elevated. Thus, it is necessary to identify new chemotherapeutic agents. The present study aimed to evaluate the effects of calein C, a sesquiterpene lactone isolated from Calea pinnatifida, on breast cancer cell lines MCF-7 (ER+), Hs578T (TN) and MDA-MB-231 (TN). Calein C significantly reduced the viability of all cell lines; however, MCF-7 cells were more responsive than MDA-MB-231 or Hs578T cells. Thus, the MCF-7 cell line was selected for further investigation. We demonstrated that calein C inhibited cell cycle progression in MCF-7 cells at M-phase. Increased frequency of mitosis was observed in calein C-treated samples compared to the control group, especially of the cell population in initial stages of the mitosis. These events were associated with the ability of calein C to modulate expression levels of critical regulators of mitosis progression. We observed a significant reduction in the relative mRNA abundance of PLK1 and AURKB along with a concomitant increase in CDKN1A (p21) in treated samples. In addition, calein C induced apoptosis in MCF-7 cells due to, at least in part, its ability to reduce the BCL2/BAX ratio. Therefore, our data provide evidence that calein C is an important antimitotic agent and should be considered for further in vivo investigations.

Pro-apoptotic activity of ruthenium 1-methylimidazole complex on non-small cell lung cancer.

Herein, novel ruthenium(II) complexes containing 1-methylimidazole as a ligand were obtained with the following formulas: [RuCl(1Meim)(dppb)(bpy)]Cl (1), [RuCl(1Meim)(dppb)(4,4'-DMbpy)]Cl (2), [RuCl(1Meim)(dppb)(5,5'-DMbpy)]Cl (3) and [RuCl(1Meim)(dppb)(phen)]Cl (4) where, 1Meim = 1-methylimidazole, dppb = 1,4-Bis(diphenylphosphino)butane, bpy = 2,2'-bipyridine, 4,4'-DMbpy = 4,4'-dimethyl-2,2'-bipyridine, 5,5'-DMbpy = 5,5'-dimethyl-2,2'-bipyridine and phen = 1,10-phenanthroline. Additionally, crystal structures containing the cations of (1) and (3) were obtained when the counter ion was exchanged, leading to the formation of [RuCl(1Meim)(dppb)(bpy)]PF6 (5) and [RuCl(1Meim)(dppb)(5,5'-DMbpy)]PF6 methanol solvate (6) where PF6 = hexafluorophosphate, showing one 1-methylimidazole molecule coordinated through the imidazole nitrogen, as expected. The complexes were characterized by elemental analysis, molar conductivity, infrared and UV-Vis spectroscopy, 1H, 13C{1H} and 31P{1H} NMR, mass spectrometry and cyclic voltammetry. The interactions of complexes 1-4 with DNA and human serum albumin (HSA) were evaluated, and the cytotoxicity profiles of compounds 1-4 were determined using four different tumor cell lines derived from human cancers (melanoma: HT-144, colon: HCT-8, breast: MDA-MB-231 and lung: A549). A higher cytotoxic activity was observed for compound (3) against non-small cell lung cancer (A549). Complex (3) inhibited the clonogenic capacity and cell cycle progression of A549 cells and induced apoptosis involving mitochondrial pathway activation. Therefore, the data obtained in the present study support further investigations concerning molecular targets of complex (3) in non-small cell lung cancer.

Synthetic resveratrol-curcumin hybrid derivative inhibits mitosis progression in estrogen positive MCF-7 breast cancer cells.

Curcumin (1) and resveratrol (2) are bioactive natural compounds that display wide pharmacological properties, including antitumor activity. However, their clinical application has been limited due to their low solubility and bioavailability. Nevertheless, independent studies have considered these compounds as interesting prototypes for developing new chemical structures useful for anticancer therapy. Here in, we report the synthesis of novel curcumin-like hydrazide analogues (3a and 3b), and a series of curcumin-resveratrol hybrid compounds (4a-f), and the evaluation of their cytotoxic potential on three tumor cell lines MCF-7 (breast), A549 (lung), and HepG2 (liver). Cell viability was significantly reduced in all tested cell lines when compounds 4c-4e were used. The IC50 values for these compounds on MCF-7 cells were lower than those for curcumin, resveratrol, or curcumin combined with resveratrol. We evidenced that 4c promoted a drastic increase of G2/M population. The accumulation of cells in mitosis onset in treated cultures was due to, at least in part, the ability of 4c to modulate nuclear kinase proteins, which orchestrate important events in mitosis progression. We have also observed significant reduction of the relative RNAm abundance of CCNB1, PLK1, AURKA, AURKB in samples treated with 4c, with concomitant increase of CDKN1A (p21). Thus, compound 4c is a promising multi-target antitumor agent that should be considered for further in vivo studies.

Design, synthesis and pharmacological evaluation of N-benzyl-piperidinyl-aryl-acylhydrazone derivatives as donepezil hybrids: Discovery of novel multi-target anti-alzheimer prototype drug candidates.

A new series of sixteen multifunctional N-benzyl-piperidine-aryl-acylhydrazones hybrid derivatives was synthesized and evaluated for multi-target activities related to Alzheimer's disease (AD). The molecular hybridization approach was based on the combination, in a single molecule, of the pharmacophoric N-benzyl-piperidine subunit of donepezil, the substituted hydroxy-piperidine fragment of the AChE inhibitor LASSBio-767, and an acylhydrazone linker, a privileged structure present in a number of synthetic aryl- and aryl-acylhydrazone derivatives with significant AChE and anti-inflammatory activities. Among them, compounds 4c, 4d, 4g and 4j presented the best AChE inhibitory activities, but only compounds 4c and 4g exhibited concurrent anti-inflammatory activity in vitro and in vivo, against amyloid beta oligomer (AßO) induced neuroinflammation. Compound 4c also showed the best in vitro and in vivo neuroprotective effects against AßO-induced neurodegeneration. In addition, compound 4c showed a similar binding mode to donepezil in both acetylated and free forms of AChE enzyme in molecular docking studies and did not show relevant toxic effects on in vitro and in vivo assays, with good predicted ADME parameters in silico. Overall, all these results highlighted compound 4c as a promising and innovative multi-target drug prototype candidate for AD treatment.

Casearin D inhibits ERK phosphorylation and induces downregulation of cyclin D1 in HepG2 cells.

Cancer is a public health problem which represents the second cause of death in the world. In this framework, it is necessary to identify novel compounds with antineoplastic potential. Plants are an important source for discovering novel compounds with pharmacological potential. In this study, we aimed to investigate the antiproliferative potential of isolated compounds from Casearia sylvestris on tumor cell lines. Crude extract effectively reduced cell viability of 4 tumor cell lines (HepG2, A549, U251-MG, and HT-144) after 48h treatment. HepG2 and HT-144 were the most responsive cells. Three fractions (aqueous ethanol, n-hexane and ethyl acetate) were tested against HepG2 and HT-144 cells and we observed that compounds with antiproliferative activity were concentrated in n-hexane and ethyl acetate fractions. The casearins A, G and J were isolated from n-hexane fraction, while casearin D was obtained from ethyl acetate fraction. We demonstrated that casearin D significantly inhibited the clonogenic capacity of HepG2 cells after 24h exposure indicating its antiproliferative activity. In addition, G1/S transition cell cycle arrest in HepG2 cells was also observed. These effects are related, at least in part, to ability of the casearin D in reducing ERK phosphorylation and cyclin D1 expression levels.

Alkaloids derived from flowers of Senna spectabilis, (-)-cassine and (-)-spectaline, have antiproliferative activity on HepG2 cells for inducing cell cycle arrest in G1/S transition through ERK inactivation and downregulation of cyclin D1 expression.

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine in this century. Unfortunately, most patients are diagnosed at advanced stage, when the treatment options are palliative. Consequently, the search for novel therapeutic options is imperative. In the context, the plants represent an important source for discovering of novel compounds with pharmacological potential including antineoplastic agents. Herein, we aimed to investigate in vitro antiproliferative and cytotoxic potentials of an alkaloid mixture derived from Senna spectabilis, (−)-cassine (1) and (−)-spectaline (2). These alkaloids reduced cell viability in a concentration-dependent manner of six tumor cell lines. From initial screening, HepG2 cells were selected for further investigations. We show that alkaloids 1/2 have an important antiproliferative activity on HepG2 cells due to their ability in inducing cell cycle arrest in G1/S transition. This effect was associated to ERK inactivation and down-regulation of cyclin D1 expression. In addition, we evidenced a disruption of the microfilaments and microtubules in a consequence of the treatment. Taken together, the data showed by the first time that alkaloids 1/2 strongly inhibit cell proliferation of hepatocellular carcinoma cells. Therefore, they represent promise antitumor compounds against liver cancer and should be considered for further anticancer in vivo studies.