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Background Cell culture (spheroid and 2D monolayer cultures) is an essential tool in drug discovery. Piperlongumine (PLN), a naturally occurring alkaloid present in the long pepper (Piper longum), has been implicated in the regulation of GSTP1 activity. In vitro treatment of cancer cells with PLN increases ROS (reactive oxygen species) levels and induces cell death, but its molecular mode of action has not been entirely elucidated. Methods In this study, we correlated the antiproliferative effects (2D and 3D cultures) of PLN (CAS 20069–09-4, Sigma-Aldrich) with morphological and molecular analyses in HepG2/C3A cell line. We performed assays for cytotoxicity (MTT), comet assays for genotoxicity, induction of apoptosis, analysis of the cell cycle phase, and analysis of the membrane integrity by flow cytometry. Relative expression of mRNA of genes related to proliferation, apoptosis, cell cycle control, metabolism of xenobiotics, and reticulum endoplasmic stress. Results PLN reduced the cell proliferation by the cell cycle arrest in G2/M. Changes in the mRNA expression for CDKN1A (4.9x) and CCNA2 (0.5x) of cell cycle control genes were observed. Cell death occurred due to apoptosis, which may have been induced by increased expression of proapoptotic mRNAs (BAK1, 3.1x; BBC3, 2.4x), and by an increase in 9 and 3/7 active caspases. PLN induced cellular injury by ROS generation and DNA damage. DNA damage induced MDM2 signaling (3.0x) associated with the appearance of the monastral spindle in mitosis. Genes associated with ROS degradation also showed increased mRNA expression (GSR, 2.0x; SOD1, 2.1x). PLN induce endoplasmic reticulum stress with the increase in the mRNA expression of ERN1 (4.5x) and HSPA14 (2.2x). The xenobiotic metabolism showed increased mRNA expression for CYP1A2 (2.2x) and CYP3A4 (3.4x). In addition to 2D culture, PLN treatment also inhibited the growth of 3D culture (spheroids). Conclusion Thus, the findings of our study show that several gene expression biomarkers (mRNAs) and monastral spindle formation indicated the many pathways of damage induced by PLN treatment that contributes to its antiproliferative effects. Graphical abstract

Duchenne muscular dystrophy is the most common and severe form of progressive muscular dystrophy. Previous results showed an increased survival in double knockout mice (dko) when treated with adipose-derived CD146+ cells. In this study, we analyzed the effect of CD146+ cells compared to mesenchymal stem/stromal cells (MSCs) derived from the same human adipose sample when injected in the dko mouse model without immunosuppression. Both CD146+ cells and MSCs increased the survival of treated mice when compared to vehicle-injected mice, with a more prominent effect of CD146+ cells than MSCs. Both CD146+ cells and MSCs suppressed peripheral blood mononuclear cell proliferation, indicating immunomodulatory properties. Co-culture experiments showed that MSCs have a more inflammatory profile expression, and angiogenesis assay showed that CD146+ cells can improve blood vessel formation. CD146+ cells can extend survival of muscular dystrophy mice more efficiently than MSCs, possibly due to immunomodulatory and angiogenic properties. Further investigations focusing on exogenous CD146+ cell role in vivo will improve cell therapy understanding and effectiveness.

Studies that evaluated the mechanisms of action of Plumbagin (PLB) and its toxicity may contribute to future therapeutic applications of this compound. We investigate biomarker important in the mechanisms of action correlate the expression of mRNA with the cytotoxic and genotoxic effects of PLB on HepG2/C3A. In the analysis of cytotoxicity, PLB decreased cell viability and membrane integrity at concentrations ≥ 15μM. Xenobiotic-metabolizing system showed strong mRNA induction of CYP1A1, CYP1A2, and CYP3A4, suggesting extensive metabolization. PLB induced apoptosis and an increase in the mRNA expression of genes BBC3, CASP3, and CASP8. At a concentration of 15μM, there was a reduction in the expression of PARP1 mRNA and an increase in the expression of BECN1 mRNA, suggesting that PLB may also induce cell death by autophagy. PLB induced an arrest at the G2/M phase due to DNA damage, as observed in the comet assay. This damage is associated with the increased mRNA expression of genes p21, GADD45A, and H2AFX and with changes in the expression of proteins H2AX, p21, p53, Chk1, and Chk2. These results allow a better understanding of the cellular action of PLB and of its toxicity, thereby contributing to the development of PLB-based drugs, with markers of mRNA expression possibly playing a role as indicators for monitoring toxicity in human cells.

Plumbagin (PLB) is a phytochemical being used for centuries in traditional medicines. Recently, its capacity to inhibit the development of human tumors has been observed, through the induction of apoptosis, cell cycle arrest, and inhibition of angiogenesis and metastasis. Here we evaluated the mechanism of action of PLB in the kidney adenocarcinoma 786-O cell line, which are metabolizing cells important for toxicology studies. After the treatment with PLB, we observed increased apoptosis and cell cycle arrest in S and G2/M phases, starting at 5 µM. In addition, PLB was cytotoxic, genotoxic and induced loss of cell membrane integrity. Regarding gene expression, treatment with 7.5 µM PLB reduced the amount of MTOR, BCL2 and ATM transcripts, and increased CDKN1A (p21) transcripts. Phosphorylation levels of yH2AX was increased and MDM2 protein level was reduced following the treatment with PLB, demonstrating its genotoxic effect. Our results suggest that PLB acts in molecular pathways related to the control of proliferation and cell death in 786-O cells.

Curcumin (Cur), is a pigment with antiproliferative activity but has some pharmacokinetic limitations, which led researchers to look for more effective structure analogs. This work investigated the effects of Cur and compared them with the two analogs, demethoxycurcumin (DeMC) and dimethoxycurcumin (DiMC), to elucidate their mechanisms of action. The cytotoxic, antiproliferative, and genotoxic effects these compounds were correlated based on gene expression analysis in the human renal adenocarcinoma cells (786-O). Cur decreased CYP2D6 expression and exhibited cytotoxic effects, such as inducing monopolar spindle formation and mitotic arrest mediated by the increase in CDKN1A (p21) mRNA. This dysregulation induced cell death through a caspase-independent pathway but was mediated by decrease in MTOR and BCL2 mRNA expression, suggesting that apoptosis occurred by autophagy. DeMC and DiMC had similar effects in that they induced monopolar spindle and mitotic arrest, were genotoxic, and activated GADD45A, an important molecule in repair mechanisms, and CDKN1A. However, the induction of apoptosis by DeMC was delayed and regulated by the decrease of antiapoptotic mRNA BCL.XL and subsequent activation of caspase 9 and caspase 3/7. DiMC treatment increased the expression of CYP1A2, CYP2C19, and CYP3A4 and exhibited higher cytotoxicity compared with other compounds. It induced apoptosis by increasing mRNA expression of BBC3, MYC, and CASP7 and activation of caspase 9 and caspase 3/7. These data revealed that different gene regulation processes are involved in cell death induced by Cur, DeMC, and DiMC. All three can be considered as promising chemotherapy candidates, with DiMC showing the greatest potency.

In cancer, mesenchymal stem/stromal cells (MSCs) have been considered as vehicles for targeted delivery of drugs due to their inherent tropism toward primary and metastatic tumors. However, it is still unclear whether MSCs could be therapeutically explored without significant harm, since a great amound of evidence indicates that MSCs are able to exert both tumor-suppressive and pro-oncogenic effects. Here, we discuss how MSCs might adopt a pro- or anti-inflammatory profile in response to changes within the tumor microenvironment and how these features may lead to opposite outcomes in tumor development. Additionally, we address how differences in experimental design might impact interpretation and consistency of the current literature in this specific field. Finally, we point-out critical issues to be addressed at a pre-clinical stage, regarding safety and therapeutic effectiveness of MSCs application in cancer treatment.

Dimethoxycurcumin (DiMC), a synthetic analog of curcumin, was shown to have antiproliferative activity in human tumor cell lines. Therefore, we investigated its cytotoxic, antiproliferative, genotoxic, and apoptotic effect and correlated these evaluations with the expression of transcripts and proteins in the human hepatocellular carcinoma cell line (HepG2/C3A). Treatment with DiMC resulted in increased CYP2E1, CYP2C19 and CYP1A2 transcripts levels and was cytotoxic (≥10 μM). DiMC caused mitotic arrest by inducing monopolar spindle formation and was genotoxic increasing expression of the CDKN1A, GADD45A and PARP1 gene, key effectors in the cell cycle arrest and DNA repair pathways, respectively. This genotoxicity was caused by generation of reactive oxygen species and reduction of antioxidant proteins levels. Furthermore, we observed a decrease in important proteins involved in DNA repair. In addition to the observed apoptotic morphology and the presence of annexin labeling, we observed increased expression of BAK1 and CASP7 genes and caspase 3/7 protein activity, showing that these effects caused apoptosis through the intrinsic pathway in HepG2/C3A cells. Our results indicate that DiMC modulates important molecular targets leading to cell death even in metabolic competent cells models has considerable potential in anticancer therapy.

SPOAN syndrome is a neurodegenerative disorder mainly characterized by spastic paraplegia, optic atrophy and neuropathy (SPOAN). Affected patients are wheelchair bound after 15 years old, with progressive joint contractures and spine deformities. SPOAN patients also have sub normal vision secondary to apparently non-progressive congenital optic atrophy. A potential causative gene was mapped at 11q13 ten years ago. Here we performed next-generation sequencing in SPOAN-derived samples. While whole-exome sequencing failed to identify the causative mutation, whole-genome sequencing allowed to detect a homozygous 216-bp deletion (chr11.hg19:g.66,024,557_66,024,773del) located at the non-coding upstream region of the KLC2 gene. Expression assays performed with patient’s fibroblasts and motor neurons derived from SPOAN patients showed KLC2 overexpression. Luciferase assay in constructs with 216-bp deletion confirmed the overexpression of gene reporter, varying from 48 to 74%, as compared with wild-type. Knockdown and overexpression of klc2 in Danio rerio revealed mild to severe curly-tail phenotype, which is suggestive of a neuromuscular disorder. Overexpression of a gene caused by a small deletion in the non-coding region is a novel mechanism, which to the best of our knowledge, was never reported before in a recessive condition. Although the molecular mechanism of KLC2 up-regulation still remains to be uncovered, such example adds to the importance of non-coding regions in human pathology Fil: Melo, Uira S.. Universidade de Sao Paulo; Brasil Fil: Macedo Souza, Lucia I.. Universidade de Sao Paulo; Brasil Fil: Figueiredo, Thalita. Federal University of Paraiba; Brasil. Paraiba State University; Brasil Fil: Muotri, Alysson R. University of California at San Diego; Estados Unidos Fil: Gleeson, Joseph G.. The Rockefeller University; Estados Unidos Fil: Coux, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentina Fil: Armas, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentina Fil: Calcaterra, Nora Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentina Fil: Kitajima, João P.. Mendelics Genomic Analysis; Brasil Fil: Amorim, Simone. Universidade de Sao Paulo; Brasil Fil: Olávio, Thiago R.. Universidade de Sao Paulo; Brasil Fil: Griesi Oliveira, Karina. Universidade de Sao Paulo; Brasil Fil: Coatti, Giuliana C.. Universidade de Sao Paulo; Brasil Fil: Rocha, Clarissa R.R. Universidade de Sao Paulo; Brasil Fil: Martins Pinheiro, Marinalva. Universidade de Sao Paulo; Brasil Fil: Menck, Carlos F.M.. Universidade de Sao Paulo; Brasil Fil: Zaki, Maha S.. National Research Center. EL Cairo; Egipto Fil: Kok, Fernando. Universidade de Sao Paulo; Brasil Fil: Zatz, Mayana. Universidade de Sao Paulo; Brasil Fil: Santos, Silvana. Federal University of Paraiba; Brasil. Paraiba State University; Brasil