Evaluation of infliximab-induced genotoxicity and possible action on BCL-2 and P53 genes.

Although the last pandemic created an urgency for development of vaccines, there was a continuous and concerted effort to search for therapeutic medications among existing drugs with different indications. One of the medications of interest that underwent this change was infliximab (IFM). This drug is used as an anti-inflammatory, predominantly in patients with Crohn 's disease, colitis ulcerative, and rheumatoid arthritis. In addition to these patients, individuals infected with Coronavirus Disease (COVID-19) were administered this chimeric monoclonal antibody (IMF) to act as an immunomodulator for patients in the absence of comprehensive research. Consequently, the present study aimed to examine the genotoxic effects attributed to IFM treatment employing different assays in vivo using mouse Mus musculus. Therefore, IFM was found to induce genotoxic effects as evidenced by the comet assay but did not demonstrate genotoxic potential utilizing mouse bone marrow MN test. The results of evaluating the expression of the P53 and BCL-2 genes using RT-qPCR showed stimulation of expression of these genes at 24 hr followed by a decline at 48 hr. Although the comet assay provided positive results, it is noteworthy that based upon negative findings in the micronucleus test, the data did not demonstrate significant changes in the genetic material that might affect the therapeutic use of IFM. The stimulation of expression of P53 and BCL-2 genes at 24 hr followed by a decline at 48 hr suggest a transient, if any, effect on genetic material. However, there is still a need for more research to more comprehensively understand the genotoxic profile of this medication.

Design, Synthesis and Evaluation of Novel Derivatives of Curcuminoids with Cytotoxicity.

Curcumin and curcuminoids have been discussed frequently due to their promising functional groups (such as scaffolds of α,ß-unsaturated ß-diketone, α,ß-unsaturated ketone and ß'-hydroxy-α,ß-unsaturated ketone connected with aromatic rings on both sides) that play an important role in various bioactivities, including antioxidant, anti-inflammatory, anti-proliferation and anticancer activity. A series of novel curcuminoid derivatives (a total of 55 new compounds) and three reference compounds were synthesized with good yields using three-step organic synthesis. The anti-proliferative activities of curcumin derivatives were examined for six human cancer cell lines: HeLaS3, KBvin, MCF-7, HepG2, NCI-H460 and NCI-H460/MX20. Compared to the IC50 values of all the synthesized derivatives, most α,ß-unsaturated ketones displayed potent anti-proliferative effects against all six human cancer cell lines, whereas ß'-hydroxy-α,ß-unsaturated ketones and α,ß-unsaturated ß-diketones presented moderate anti-proliferative effects. Two potent curcuminoid derivatives were found among all the novel derivatives and reference compounds: (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a). These were selected for further analysis after the evaluation of their anti-proliferative effects against all human cancer cell lines. The results of apoptosis assays revealed that the number of dead cells was increased in early apoptosis and late apoptosis, while cell proliferation was also decreased after applying various concentrations of (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) to MCF-7 and HpeG2 cancer cells. Analysis of the gene expression arrays showed that three genes (GADD45B, SESN2 and BBC3) were correlated with the p53 pathway. From the quantitative PCR analysis, it was seen that (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) effectively induced the up-regulated expression of GADD45B, leading to the suppression of MCF-7 cancer cell formation and cell death. Molecular docking analysis was used to predict and sketch the interactions of the GADD45B-α,ß-unsaturated ketone complex for help in drug design.

Zinc oxide nanoparticles promote the aging process in a size-dependent manner.

Zinc oxide (ZnO) nanoparticles (NPs) are generally utilized in cosmetic goods, sheds, biosensors, and delivery of drug. As in vitro ideal systems, mesenchymal stem cells (MSCs) are used to test acute toxicity. In the present study, size-dependent cytotoxicity effects of ZnO NPs on MSCs were assessed. Bone marrow and adipose MSCs were treated with ZnO NPs with average sizes of 10-30 and 35-45 nm. The 5 and 10 µg/ml concentrations of ZnO NP were found to be the safe concentrations for the NP sizes of 10-30 and 35-45 nm, respectively. Cell-cycle analysis indicated that the small size of ZnO NPs has more negative effects on the process of cell entry to DNA synthesis when compared to the larger size. The results of the ß-galactosidase test showed the promotion of the aging process in the cells treated with the smaller size of ZnO NPs. Both sizes of the NP were found to upregulate the aging-related genes NF-kB and p53 and downregulate the anti-aging gene Nanog. To sum up, the smaller size of ZnO NPs can enhance the aging process in the cells.

Low-dose DNA demethylating therapy induces reprogramming of diverse cancer-related pathways at the single-cell level.

BACKGROUND: Epigenetic reprogramming using DNA demethylating drugs is a promising approach for cancer therapy, but its efficacy is highly dependent on the dosing regimen. Low-dose treatment for a prolonged period shows a remarkable therapeutic efficacy, despite its small demethylating effect. Here, we aimed to explore the mechanisms of how such low-dose treatment shows this remarkable efficacy by focusing on epigenetic reprograming at the single-cell level. METHODS: Expression profiles in HCT116 cells treated with decitabine (DAC) were analyzed by single-cell RNA-sequencing (scRNA-seq). Functional consequences and DNA demethylation at the single-cell level were analyzed using cloned HCT116 cells after DAC treatment. RESULTS: scRNA-seq revealed that DAC-treated cells had highly diverse expression profiles at the single-cell level, and tumor-suppressor genes, endogenous retroviruses, and interferon-stimulated genes were upregulated in random fractions of cells. DNA methylation analysis of cloned HCT116 cells revealed that, while only partial reduction of DNA methylation levels was observed in bulk cells, complete demethylation of specific cancer-related genes, such as cell cycle regulation, WNT pathway, p53 pathway, and TGF-ß pathway, was observed, depending upon clones. Functionally, a clone with complete demethylation of CDKN2A (p16) had a larger fraction of cells with tetraploid than parental cells, indicating induction of cellular senescence due to normalization of cell cycle regulation. CONCLUSIONS: Epigenetic reprogramming of specific cancer-related pathways at the single-cell level is likely to underlie the remarkable efficacy of low-dose DNA demethylating therapy.

Targeting DNA and mutant p53 by a naphthalimide derivative, NA20, exhibits selective inhibition in gastric tumorigenesis by blocking mutant p53-EGFR signaling pathway.

Mutations of p53 in cancer cells not only subvert its antiproliferative properties but can also promote various oncogenic responses through a gain-of-function activity. Pharmacological manipulation of the mutant p53 pathway by specific compounds could be an effective strategy for cancer therapy. We show here that gain-of-function p53 mutation in gastric cancer cells promotes tumorigenesis by enhancing p53-EGFR (epidermal growth factor receptor) signaling pathway, and such process can be blocked by small molecule NA20, a naphthalimide derivative that exhibited selective inhibition in p53 mutant gastric cancer cell lines. We found that targeting DNA and blocking the mutant p53-drived carcinogenicity accounted for the primary antitumor effect of NA20 in gastric tumor models. NA20 bound to DNA and p53 identified by a combination of drug tracking, DNA relaxation assay and coimmunoprecipitation-mass spectrometry (CoIP-MS) detection, which led to the p21 activation and the suppression of EGFR signal cascading, thereby evoking cell cycle arrest and cell apoptosis, finally leading to cancer cell inhibition both in vitro and in vivo. Taken together, these results suggest that NA20 may be a potential candidate for gastric cancer therapy.

LKB1 inactivation leads to centromere defects and genome instability via p53-dependent upregulation of survivin.

Inactivating mutations in the liver kinase B1 (LKB1) tumor suppressor gene underlie Peutz-Jeghers syndrome (PJS) and occur frequently in various human cancers. We previously showed that LKB1 regulates centrosome duplication via PLK1. Here, we report that LKB1 further helps to maintain genomic stability through negative regulation of survivin, a member of the chromosomal passenger complex (CPC) that mediates CPC targeting to the centromere. We found that loss of LKB1 led to accumulation of misaligned and lagging chromosomes at metaphase and anaphase and increased the appearance of multi- and micro-nucleated cells. Ectopic LKB1 expression reduced these features and improved mitotic fidelity in LKB1-deficient cells. Through pharmacological and genetic manipulations, we showed that LKB1-mediated repression of survivin is independent of AMPK, but requires p53. Consistent with the key influence of LKB1 on survivin expression, immunohistochemical analysis indicated that survivin is highly expressed in intestinal polyps from a PJS patient. Lastly, we reaffirm a potential therapeutic avenue to treat LKB1-mutated tumors by demonstrating the increased sensitivity to survivin inhibitors of LKB1-deficient cells.

Acrolein contributes to urothelial carcinomas in patients with chronic kidney disease.

BACKGROUND: Urothelial carcinomas (UCs) are highly prevalent in patients with end-stage renal disease. Chronic kidney disease (CKD) is the predecessor of end-stage renal disease, and it is also associated with UC. However, the interplay between CKD and UC lacks solid evidence. Acrolein is produced by polyamines and has been suggested to be the uremic "toxin." The level of acrolein correlates well with chronic renal failure. We recently found that acrolein-induced DNA damage and inhibited DNA repair in urothelial cells, which contribute to bladder cancer. Therefore, we hypothesize that acrolein is involved in the formation of UC in patients with CKD. MATERIALS AND METHODS: A total of 62 UC patients and 43 healthy control subjects were recruited. Acrolein-DNA (Acr-dG) adducts and p53 gene mutations in UC tissues, plasma acrolein-protein conjugates (Acr-PC) and S-(3-hydroxypropyl)-N-acetylcysteine levels, and urinary Acr metabolites were analyzed in these patients. RESULTS: Acr-dG levels were statistically correlated with CKD stages in UC patients (P < 0.01). Most p53 mutations were G to A and G to T mutations in these patients, and 50% of mutations at G:C pairs occurred in CpG sites, which is similar to the mutational spectra induced by Acr-dG adducts. Acr-PC levels in the plasma of UC patients with CKD were significantly higher than those of control subjects (P < 0.001). Altered urinary S-(3-hydroxypropyl)-N-acetylcysteine was also found in UC patients with CKD compared to control subjects (P < 0.005). CONCLUSION: These results indicate that acrolein acts as an endogenous uremic toxin and contributes to UC formation in patients with CKD.

High-Intensity Training and Saffron: Effects on Breast Cancer-related Gene Expression.

PURPOSE: Exercise training and some herbal components have an anticancer function and can suppress tumor growth. However, the role of these protective factors in altering breast cancer-related gene expression is still unknown. Thus, this study aimed to assess the effect of 4 wk of high-intensity interval training (HIIT) and saffron (Crocus sativus L.) aqueous extract (SAE) on Sirtuin-1 (SIRT1), human telomerase reverse transcriptase (hTERT), and p53 gene expression in female mice breast tumor tissue induced by 4T1 cell line. METHODS: This study was performed on female BALB/c mice. The 4T1 breast cancer cells were subcutaneously implanted, and mice were randomly sorted into the following groups: control, HIIT, SAE, HIIT + SAE (n = 10 mice per group), and sham (n = 4 mice per group). Mice were sacrificed at the end of the intervention period, and the expression of SIRT-1, hTERT, and p53 was determined by real-time polymerase chain reaction. RESULTS: The mRNA level of SIRT1 was increased in the HIIT + SAE group compared with the HIIT and control groups (P = 0.007 and P = 0.03, respectively). Moreover, the amount of mRNA of p53 was increased after a 4-wk HIIT compared with the control and HIIT + SAE groups in tumor tissue (P = 0.03 and P = 0.02, respectively). No change was found in the mRNA expression of hTERT between groups (P = 0.92). CONCLUSIONS: These findings suggest that HIIT may reduce tumor burden through the upregulation of p53 associated with tumor suppression pathway. In contrast, the combination of HIIT and SAE did not alter p53 and SIRT1 expression levels and may suppress tumor growth by other mechanisms.

[Analysis of the potential role of SET in chromium-induced malignant transformation cells based on quantitative proteomics].

Objective: To investigate alteration of proteins profile in malignant transformation bronchial epithelial cells(16HBE-T) induced by hexavalent chromium[(Cr(VI))] and analyze the expression level of SET protein, then to provide some new insights for the carcinogenesis mechanism of Cr(VI). Methods: Total protein was extracted from 16HBE cells and was alkylated and desalinated before digested into peptides. The products were labeled with Tandem Mass Tag (TMT) and identified using LC-ESI-MS/MS. Results: A total of 3 517 proteins were found, expression differences greater than 1.5 or less 0.67 times were to found have 185 and 201 proteins, respectively. Gene enrichment analysis revealed that differential proteins were mainly involved in autophagy, DNA damage repair, RNA processing and other biological processes. Western blot results showed the expression level of SET was significantly increased while downregulated in histone H3K18/27 acetylation and p53 protein. Conclusion: Proteins involved in multiple biological processes altered in 16HBE-T cells and regulation mode of SET inhibiting histone H3K18/27 acetylation regulating transcriptional activity of p53 may paly an important role in Cr(VI)-association carcinogenesis.

Man-made mineral fiber effects on the expression of anti-oncogenes P53 and P16 and oncogenes C-JUN and C-FOS in the lung tissue of Wistar rats.

Man-made mineral fibers (MMMFs) are substitutes for asbestos. MMMFs are widely used as insulation, but their molecular mechanisms underlying the tumorigenic effects in vivo have been poorly studied. For this reason, this work aimed to explore the properties and carcinogenic molecular mechanisms of MMMFs. The three MMMFs, rock wool (RW), glass fibers (GFs), and ceramic fibers (CFs), were prepared into respirable dust. Particle size, morphology, and chemical composition were analyzed by laser particle analyzer, scanning electron microscope, and X-ray fluorescence spectrometer, respectively. The Wistar rats were administered multiple intratracheal instillations of three MMMFs once a month. Then, several parameters (e.g. body mass, lung mass, and lung histology) were measured at 1, 3, and 6 months. After that, levels of P53, P16, C-JUN, and C-FOS mRNA and protein were measured by quantitative real-time reverse transcription polymerase chain reaction and Western blotting. This work found that exposure to MMMFs could influence the growth of body mass and increase lung mass. General conditions showed white nodules and irregular atrophy. In addition, MMMFs could lead to inactivation of anti-oncogene P16 and activation of proto-oncogenes (C-JUN and C-FOS) in the mRNA and protein levels, in which GF and CF were more obvious compared with RW. The effect of MMMFs was different, which may be related to the physical and chemical characteristics of different MMMFs. In conclusion, MMMFs (GF and CF) could induce an unbalanced expression of cancer-related genes in the lung tissues of rats. The understanding of the determinants of toxicity and carcinogenicity provides a scientific basis for developing and introducing new safer MMMF products, and the present study provides some useful insights into the carcinogenic mechanism of MMMFs.

Reactivation of p53 gene by MDM2 inhibitors: A novel therapy for cancer treatment.

Cancer is an uncontrolled and abnormal growth of cells in the body. Gene that guards the cell cycle and function as tumor suppressor is p53 (also called as the guardian of the genome) which is encoded by the TP53 gene. Various events like DNA damage, heat shock, hypoxia and oncogene over expression, results in activation of p53.Thus, it plays a major role as a regulatory protein which regulates various diverse biological responses, responsible for genetic stability by preventing genome mutation. More than 50% mutations in human cancers along with the increase in expression of murine double minute 2 gene (mdm2), has been found as one of the reason for cancer progression. Murine double minute 2 (MDM2) is the negative regulator of p53 gene forming an autoregulatory feedback loop controlling each other cellular levels. Murine double minute 2 is unique E3 ubiquitin ligase protein which is responsible for ubiquitination and degradation of p53 gene. Many drugs/compounds have been developed for reactivation of p53 gene by inhibiting MDM2 interaction with p53, using MDM2 antagonism, inhibiting E3 ubiquitination of p53. Many compounds have entered clinical trials in haematological malignancies. This review will throw some light on reactivation of p53 gene by MDM2 and its homologues.

Resveratrol Induces Apoptosis in Murine Prostate Cancer Cells via Hypoxia-Inducible Factor 1-alpha (HIF-1α)/Reactive Oxygen Species (ROS)/P53 Signaling.

BACKGROUND Resveratrol, a polyphenol found on the surface of red fruits, is able to suppress many kinds of malignancies. Nevertheless, its mechanism of action is not yet clear. Consequently, this study aimed to elucidate its influence and explore the etiology of PCCs (prostate cancer cells). MATERIAL AND METHODS The proliferation of prostate cancer cells was determined by CCK-8 assay. Cell apoptosis was determined by Hoechst staining FC assay. Cell migration was detected by scratch test. The levels of apoptosis-related protein were detected by Western blot analysis. RESULTS It was discovered that resveratrol suppresses cellular survival and migration and enhances cell death. In addition, it was revealed that resveratrol elevated ROS concentration and expression of biomarker of cell death Bax, while inhibiting Bcl2, an anti-apoptotic protein, and reinforcing expression of p53. Moreover, resveratrol remarkably increased the expressions of HIF-1α and p53 in PC cells. Resveratrol suppressed cell survival and promoted cell death, but its effects were reversed after HIF-1α knockdown, suggesting that the effects of resveratrol in PC are mediated via HIF-1α. CONCLUSIONS Our findings indicate that resveratrol induces apoptosis via HIF-1α/ROS/p53 signaling in prostate cancer cells and may be a useful therapeutic agent against prostate cancer.

Protective Roles of Thymoquinone Nanoformulations: Potential Nanonutraceuticals in Human Diseases.

The focus on nanotechnology for improved bioavailability and drug delivery is of increasing importance for control of different human diseases. Therefore, numerous nanoformulations have been developed for the oral bioavailability of different drugs. This review introduces applications of nanomedicine to enhance the biological activities of thymoquinone (TQ) to control different diseases in several in vivo studies as a preliminary investigation for human disease treatment with nano-TQ. Nano-TQ effectively augments the anticancer roles of doxorubicin by upregulation of P53 and downregulation of Bcl2 and potentiates paclitaxel's apoptosis in MCF-7 breast cancer cells. Moreover, nano-TQ protects against diabetes, inflammation, CNS, and hepatotoxicity, mainly by enhancement of organs' antioxidant status. We summarize the pros and cons of several FDA approved nanoparticle-based therapeutics and discuss the roadblocks in clinical translation, along with potential nano-TQ strategies to overcome these roadblocks. From this review, we can conclude that nano-TQ may be considered as a promising nutraceutical for human health.

TP53-dependence on the effect of doxorubicin and Src inhibitor combination therapy.

The anticancer effects of Src kinase inhibitors are controversial. This study found an association between alterations in the TP53 gene and the synergy score for combination treatment with doxorubicin and an Src kinase inhibitor using human osteosarcoma cell lines (MG63 and U2OS) and human colon cancer cell line. Doxorubicin was found to activate signal transducer and activator of transcription 3 via Src kinase in cancer cells harboring alterations in TP53. A drug combination study using patient-derived cells confirmed that an Src kinase inhibitor synergizes with doxorubicin in cancer cells harboring alterations in TP53, while antagonizing its effect in cancer cells expressing wild-type TP53. Our findings suggest that genetic alterations in TP53 are a critical factor in determining the use of a combination treatment of doxorubicin and Src inhibitors.

New tanshinone I derivatives S222 and S439 similarly inhibit topoisomerase I/II but reveal different p53-dependency in inducing G2/M arrest and apoptosis.

Tanshinone I (Tanshinone-1), a major active principle of the traditional Chinese medicine Salvia miltiorrhiza, possesses excellent anticancer properties, including inhibiting proliferation, angiogenesis and metastasis and overcoming multidrug resistance (MDR). However, its direct anticancer molecular target(s) remain unknown. Here we report that tanshinone-1 and its two new derivatives, S222 and S439, directly inhibit DNA topoisomerase I/II (Top1/2). With significantly improved water solubility, S222 and S439 displayed 12- and 14-times more potent proliferative inhibition than their parent tanshinone-1 in a panel of 15 cancer cell lines. Both retained tanshinone-1's anti-MDR and anti-angiogenesis properties and its capability to reduce the phosphorylation of Stat3 at Tyr705 with apparently enhanced efficacy and in these regards, S439 was also slightly more potent than S222. Both derivatives and tanshinone-1 directly inhibited Top1 and Top2 at molecular and cellular levels; the derivatives displayed similar potency but both were more potent than tanshinone-1. The inhibition of S222 and S439 on Top1 and Top2 was also more potent than that of the Top1 inhibitor hydroxylcamptothecin and the Top2 inhibitor etoposide, respectively. Consistently, tanshinone-1 and its derivatives induced DNA double-strand breaks, G2/M arrest and apoptosis. Unexpectedly, the derivatives demonstrated different p53-dependency in inducing both cell cycle arrest and apoptosis. S222 showed no obvious p53-dependency. In contrast, S439 induced more G2/M arrest in p53-proficient cells than in p53-deficient cells while its apoptotic induction was the opposite. However, their proliferative inhibition was independent of the p53 status. Due to their structures different from the known Top1, Top2 and dual Top1/2 inhibitors, our results indicate that tanshinone-1 and its derivatives are a new type of dual Top1/2 inhibitors.

Cytotoxicity of radiocontrast dyes in human umbilical cord mesenchymal stem cells.

Radiocontrast dyes are used for a wide range of diagnostic procedures for enhancing the image of anatomical structures, pain targets, and vascular uptake. While some of these dyes show toxicity to primary cells, their effect on stem cells, particularly mesenchymal stem cells (MSCs), is unknown. This study investigates the cytotoxic effects of two clinically used radiocontrast dyes, iohexol and iopamidol, on bone marrow and human umbilical cord MSCs. Exposure to these dyes significantly affected morphology of MSCs from both sources, as treated cells appeared transparent and no longer fibroblastoid. Cell viability decreased as determined by trypan blue and Annexin-V/PI staining, in a dose dependent manner with simultaneous loss of CD90 and CD105 concurrent with spontaneous differentiation in MSCs treated with iohexol and iopamidol. In addition, significantly higher cell death was observed in MSCs exposed to iopamidol than iohexol. At a concentration of 1:1, iohexol and iopamidol induced apoptosis in 19% and 92% (<.01) of MSCs, respectively. Global transcriptome analysis of treated MSCs revealed 139 and 384 differentially expressed genes in iohexol vs control and iopamidol vs control at p ≤ .01 and 1.5-fold, respectively. This suggested that iopamidol had more significant effect on the transcription of MSCs. Based on these results a molecular mechanism of radiocontast dye induced cell death via intrinsic apoptosis pathway mediated by p53 was proposed. Since iopamidol was significantly more toxic than iohexol in human MSCs, a more careful examination of safety of radiocontrast dyes for clinical use is warranted.

Involvement of RPL11 in the enhancement of P53 stability by a podophyllum derivative, a topoisomerase II inhibitor.

In previous work, we presented experimental and theoretical evidence that D-3F or 4-N-(2-Amino-3-fluoropyridine)-4-deoxidation-4'-demethylepipofophyllotoxin induced G2 /M phase arrest and apoptosis, purportedly by increasing the expression of P53. However, the precise mechanism of D-3F action is currently unknown. Here, we investigated the mechanism by which D-3F treatment induces increased expression of P53. This study showed that D-3F definitively inhibited the activity of topoisomerase II in a dose-dependent manner and resulted in DNA damage. The results were in overall agreement with modeling and docking studies performed on D-3F. In addition, D-3F increased the levels of P53 and P21 in HeLa cells in a dose-dependent manner, this in turn prolonged the half-life of P53. Taken together, these data suggested that D-3F-mediated transient enhancement of P53 stabilization may be critical for the P53/P21 signalling pathway leading to G2 /M phase arrest on HeLa cells. Furthermore, D-3F downregulated the phosphorylation of E3 ubiquitin-protein ligase murine double minute 2 (Mdm2) at Ser166, inhibited Mdm2-mediated ubiquitination of P53, and released 60S ribosomal protein L11 (RPL11) from the nucleolus into the nucleoplasm. To conclude, the topoisomerase II inhibitor D-3F causes P53 to accumulate in HeLa cell lines by enhancing its stability as a result of DNA-damage induced RPL11 relocalization and subsequent blocking of the P53-Mdm2 feedback loop.

Nutlin-3 plus tanshinone IIA exhibits synergetic anti-leukemia effect with imatinib by reactivating p53 and inhibiting the AKT/mTOR pathway in Ph+ ALL.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by BCR/ABL kinase. Recent efforts focused on the development of more potent tyrosine kinase inhibitors (TKIs) that also inhibit mutant tyrosine kinases such as nilotinib and dasatinib. Although major advances in the treatment of this aggressive disease with potent inhibitors of the BCR/ABL kinases, patients in remission frequently relapse due to drug resistance possibly mediated, at least in part, by compensatory activation of growth-signaling pathways and protective feedback signaling of leukemia cells in response to TKI treatment. Continuous activation of AKT/mTOR signaling and inactivation of p53 pathway were two mechanisms of TKI resistance. Here, we reported that nutlin-3 plus tanshinone IIA significantly potentiated the cytotoxic and apoptotic induction effects of imatinib by down-regulation of the AKT/mTOR pathway and reactivating the p53 pathway deeply in Ph+ ALL cell line. In primary samples from Ph+ ALL patients, nutlin-3 plus tanshinone IIA also exhibited synergetic cytotoxic effects with imatinib. Of note, three samples from Ph+ ALL patients harboring T315I mutation also showed sensitivity to the combined treatment of imatinib, nutlin-3 plus tanshinone IIA. In Ph+ ALL mouse models, imatinib combined with nutlin-3 plus tanshinone IIA also exhibited synergetic effects on reduction in leukemia burden. These results demonstrated that nutlin-3 plus tanshinone IIA combined TKI might be a promising treatment strategy for Ph+ ALL patients.

Gallic Acid and Dodecyl Gallate Prevents Carbon Tetrachloride-Induced Acute and Chronic Hepatotoxicity by Enhancing Hepatic Antioxidant Status and Increasing p53 Expression.

Gallic acid (3,4,5-trihydroxybenzoic acid, GA), a natural phenolic acid has been reported as a strong antioxidant. Therefore the present study was designed to evaluate the effects of GA and dodecyl gallate (DGA) against acute and chronic carbon tetrachloride (CCl4)-induced hepatotoxicity. For acute model, rats were orally treated with GA and DGA for 7 d prior to CCl4 by intraperitoneally (i.p.) injection. For the chronic model, rats were orally treated with GA or DGA and CCl4 i.p. twice a week for four weeks. In both acute and chronic models, the CCl4-treated groups showed significantly increase in serum hepatic enzyme activities and histopathologic alterations, as well as a disruption in antioxidative status. In contrast, the treatment with GA and DGA restored serum hepatic enzymes activities, improved histopathologic alterations, increased glutathione (GSH) and decreased lipid peroxidation levels. The activities of liver antioxidant enzymes were increased by GA and DGA only in acute model. The expression of p53 gene increased about 3.5 times after GA and DGA treatments, which could result in cell death of damaged hepatocytes preventing of a lifelong liver failure. Thus, these results suggest that GA and DGA has the potential to prevent liver damages as the case of fibrosis condition.

AFB1 hepatocarcinogenesis is via lipid peroxidation that inhibits DNA repair, sensitizes mutation susceptibility and induces aldehyde-DNA adducts at p53 mutational hotspot codon 249.

Aflatoxin B1 (AFB1) contamination in the food chain is a major cause of hepatocellular carcinoma (HCC). More than 60% of AFB1 related HCC carry p53 codon 249 mutations but the causal mechanism remains unclear. We found that 1) AFB1 induces two types of DNA adducts in human hepatocytes, AFB1-8,9-epoxide-deoxyguanosine (AFB1-E-dG) induced by AFB1-E and cyclic α-methyl-γ-hydroxy-1,N2-propano-dG (meth-OH-PdG) induced by lipid peroxidation generated acetaldehyde (Acet) and crotonaldehyde (Cro); 2) the level of meth-OH-PdG is >30 fold higher than the level of AFB1-E-dG; 3) AFB1, Acet, and Cro, but not AFB1-E, preferentially induce DNA damage at codon 249; 4) methylation at -CpG- sites enhances meth-OH-PdG formation at codon 249; and 5) repair of meth-OH-PdG at codon 249 is poor. AFB1, Acet, and Cro can also inhibit DNA repair and enhance hepatocyte mutational sensitivity. We propose that AFB1-induced lipid peroxidation generated aldehydes contribute greatly to hepatocarcinogenesis and that sequence specificity of meth-OH-PdG formation and repair shape the codon 249 mutational hotspot.