Expression Of PARP Research Articles

Effects of arsenic and its main metabolites on A549 cell apoptosis and the expression of pro-apoptotic genes Bad and Bik

Objective: To investigate the effect of arsenic and its main metabolites on the apoptosis of human lung adenocarcinoma cell line A549 and the expression of pro-apoptotic genes Bad and Bik. Methods: In October 2020, A549 cells were recovered and cultured, and the cell viability was detected by the cell counting reagent CCK-8 to determine the concentration and time of sodium arsenite exposure to A549. The study was divided into NaAsO(2) exposure groups and metobol: le expoure groups: the metabolite comparison groups were subdivided into the control group, the monomethylarsinic acid exposure group (60 μmol/L) , and the dimethylarsinic acid exposure group (60 μmol/L) ; sodium arsenite dose groups were subdivided into 4 groups: control group (0) , 20, 40, 60 μmol/L sodium arsenite NaAsO(2). Hoechst 33342/propidium iodide double staining (Ho/PI) was used to observe cell apoptosis and real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression levels of Bad and Bik mRNA in cells after exposure. Western blotting was used to detect the protein expressions of Bad, P-Bad-S112, Bik, cleaved Bik and downstream proteins poly ADP-ribose polymerase PARP1 and cytochrome C (Cyt-C) , using spectrophotometry to detect the activity changes of caspase 3, 6, 8, 9. Results: Compared with the control group, the proportion of apoptotic cells in the 20, 40, and 60 μmol/L NaAsO(2) dose groups increased significantly (P<0.01) , and the expression levels of Bad, Bik mRNA, the protein expression levels of Bad, P-Bad-S112, Bik, cleaved Bik, PARP1, Cyt-C were increased (all P<0.05) , and the activities of Caspase 3, 6, 8, and 9 were significantly increased with significantly differences (P<0.05) . Compared with the control group, the expression level of Bad mRNA in the DMA exposure group (1.439±0.173) was increased with a significant difference (P=0.024) , but there was no significant difference in the expression level of Bik mRNA (P=0.788) . There was no significant differences in the expression levels of Bad and Bik mRNA in the poison groups (P=0.085, 0.063) . Compared with the control group, the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to MMA were 0.696±0.023, 0.707±0.014, 0.907±0.031, 1.032±0.016, and there was no significant difference between the two groups (P=0.469, 0.669, 0.859, 0.771) ; the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to DMA were 0.698±0.030, 0.705±0.022, 0.908±0.015, 1.029±0.010, and there was no difference between the two groups (P=0.479, 0.636, 0.803, 0.984) . Conclusion: Sodium arsenite induces the overexpression of Bad and Bik proteins, initiates the negative feedback regulation of phosphorylated Bad and the degradation of Bik, activates the downstream proteins PARP1, Cyt-C and Caspase pathways, and mediates the apoptosis of A549 cells.

PARP1 inhibition by Olaparib reduces the lethality of pancreatic cancer cells and increases their sensitivity to Gemcitabine

Pancreatic cancer (PC) is one of the tumors with the lowest survival rates due to the poor efficacy of the treatments currently used. Gemcitabine (GMZ), one of the chemotherapeutic agents employed when the tumor is unresectable, frequently fails due to the development of drug resistance. PARP1 is a relevant protein in this phenomenon and appears to be related to cancer progression in several types of tumors, including PC. To determine the relevance of PARP1 in the development and treatment of PC, we used the Panc02 cell line to generate modified PC cells with stably inhibited PARP1 expression (Panc02-L) and used GMZ, Olaparib (OLA) and GMZ+OLA as therapeutic strategies. Viability, radiosensitization, angiogenesis, migration, colony formation, TUNEL, cell cycle, multicellular tumorsphere induction and in vivo assays were performed to test the influence of PARP1 inhibition on resistance phenomena and tumor progression. We demonstrated that stable inhibition or pharmacological blockade of PARP1 using OLA-sensitized Panc02 cells against GMZ significantly decreased their IC50, reducing colony formation capacity, cell migration and vessel formation (angiogenesis) in vitro. Furthermore, in vivo analyses revealed that Panc02-L-derived (PARP1-inhibited) tumors showed less growth and lethality, and that GMZ+OLA treatment significantly reduced tumor growth. In conclusion, PARP1 inhibition, both alone and in combination with GMZ, enhances the effectiveness of this chemotherapeutic agent and represents a promising strategy for the treatment of PC.

Identification of a new member of Mortaparib class of inhibitors that target mortalin and PARP1.

Mortalin, a heat shock family protein enriched in cancer cells, is known to inactivate tumor suppressor protein p53. Abrogation of mortalin-p53 interaction and reactivation of p53 has been shown to trigger growth arrest/apoptosis in cancer cells and hence, suggested to be useful in cancer therapy. In this premise, we earlier screened a chemical library to identify potential disruptors of mortalin-p53 interaction, and reported two novel synthetic small molecules (5-[1-(4-methoxyphenyl) (1,2,3,4-tetraazol-5-yl)]-4-phenylpyrimidine-2-ylamine) and (4-[(1E)-2-(2-phenylindol-3-yl)-1-azavinyl]-1,2,4-triazole) called Mortaparib and MortaparibPlus, respectively. These compounds were shown to possess anticancer activity that was mediated through targeting mortalin and PARP1 proteins, essential for cancer cell survival and proliferation. Here, we report characterization of the third compound, {4-[(4-amino-5-thiophen-2-yl-1,2,4-triazol-3-yl)sulfanylmethyl]-N-(4-methoxyphenyl)-1,3-thiazol-2-amine}, isolated in the same screening. Extensive computational and molecular analyses suggested that the new compound has the capability to interact with mortalin, p53, and PARP1. We provide evidence that this new compound, although required in high concentration as compared to the earlier two compounds (Mortaparib and MortaparibPlus) and hence called MortaparibMild, also downregulates mortalin and PARP1 expression and functions in multiple ways impeding cancer cell proliferation and migration characteristics. MortaparibMild is a novel candidate anticancer compound that warrants further experimental and clinical attention.

A novel coumarin derivative DBH2 inhibits proliferation and induces apoptosis of chronic myeloid leukemia cells

With the development of tyrosine kinase inhibitor (TKI) resistance, finding the novel effective chemotherapeutic agent is of seminal importance for chronic myelogenous leukemia (CML) treatment. This study aims to find the effective anti-leukemic candidates and investigate the possible underlying mechanism. We synthesized the novel coumarin derivatives and evaluated their anti-leukemic activity. Cell viability assay revealed that compound DBH2 exhibited the potent inhibitory activity on the proliferation of CML K562 cells and TKI resistant K562 cells. Morphological observation and flow cytometry confirmed that DBH2 could selectively induce cell apoptosis and cell cycle arrest at G2/M phase of the K562 cells, which was further confirmed on the bone marrow cells from CML transgenic model mice and CD34+ bone marrow leukemic cells from CML patients. Treatments of DBH2 in combination with imatinib could prolong the survival rate of SCL-tTA-BCR/ABL transgenic model mice significantly. Quantitative RT-PCR revealed that DBH2 inhibited the expression of STAT3 and STAT5 in K562 cells, and caspase-3 knockout alleviated the DBH2 induced apoptosis. Furthermore, DBH2 could induce the expression of PARP1 and ROCK1 in K562 cells, which may play the important role in caspase-dependent apoptosis. Our results concluded that coumarin derivative DBH2 serves as a promising candidate for the CML treatment, especially in the combination with imatinib for the TKI resistant CML, and STAT/caspase-3 pathway was involved in the molecular mechanism of anti-leukemic activity of DBH2.

SPHK/HIF-1α Signaling Pathway Has a Critical Role in Chrysin-Induced Anticancer Activity in Hypoxia-Induced PC-3 Cells.

Hypoxia, a typical feature of locally advanced solid tumors including prostate cancer, is a critical contributor to tumor progression and causes resistance to therapy. In this study, we investigated the effects of chrysin on tumor progression in hypoxic PC-3 cells. Chrysin exerted a significant inhibitory effect on 3D cell growth under normoxic and hypoxic conditions. It also decreased the hypoxia-induced vasculogenic mimicry and attenuated the expression of HIF-1α and VE-cadherin. Chrysin inhibited HIF-1α accumulation in a concentration- and time-dependent manner in hypoxic PC-3 cells, while also suppressing the expression of HIF-1α by inhibiting SPHK-1 in both CoCl2 and hypoxic PC-3 cells. At high concentrations of chrysin, there was a greater increase in apoptosis in the hypoxic cells compared to that in normoxic cells, which was accompanied by sub-G1 phase arrest. Chrysin-induced apoptosis inhibited VEGF and Bcl-2 and induced the cleavage of PARP and caspase-3. SPHK-1 knockdown induced apoptosis and inhibited epithelial–mesenchymal transition. Consistent with the in vitro data, 50 mg/kg of chrysin suppressed the tumor growth of PC-3 xenografts by 80.4% compared to that in the untreated control group. The immunohistochemistry of tumor tissues revealed decreased Ki-67, HIF-1α, and VEGF expression in the chrysin-treated group compared to an untreated control. Western blotting data for tumor tissues showed that chrysin treatment decreased SPHK-1, HIF-1α, and PARP expression while inducing caspase-3 cleavage. Overall, our findings suggest that chrysin exerts anti-tumor activity by inhibiting SPHK-1/HIF-1α signaling and thus represents a potent chemotherapeutic agent for hypoxia, which promotes cancer progression and is related to poor prognoses in prostate cancer patients.

Deficiency of ataxia-telangiectasia mutated kinase attenuates Western-type diet-induced cardiac dysfunction in female mice.

Chronic consumption of Western‐type diet (WD) induces cardiac structural and functional abnormalities. Previously, we have shown that WD consumption in male ATM (ataxia‐telangiectasia mutated kinase) deficient mice associates with accelerated body weight (BW) gain, cardiac systolic dysfunction with increased preload, and exacerbation of hypertrophy, apoptosis, and inflammation. This study investigated the role of ATM deficiency in WD‐induced changes in functional and biochemical parameters of the heart in female mice. Six‐week‐old wild‐type (WT) and ATM heterozygous knockout (hKO) female mice were placed on WD or NC (normal chow) for 14 weeks. BW gain, fat accumulation, and cardiac functional and biochemical parameters were measured 14 weeks post‐WD. WD‐induced subcutaneous and total fat contents normalized to body weight were higher in WT‐WD versus hKO‐WD. Heart function measured using echocardiography revealed decreased percent fractional shortening and ejection fraction, and increased LV end systolic diameter and volume in WT‐WD versus WT‐NC. These functional parameters remained unchanged in hKO‐WD versus hKO‐NC. Myocardial fibrosis, myocyte hypertrophy, and apoptosis were higher in WT‐WD versus WT‐NC. However, apoptosis was significantly lower and hypertrophy was significantly higher in hKO‐WD versus WT‐WD. MMP‐9 and Bax expression, and Akt activation were higher in WT‐WD versus WT‐NC. PARP‐1 (full‐length) expression and mTOR activation were lower in WT‐WD versus hKO‐WD. Thus, ATM deficiency in female mice attenuates fat weight gain, preserves heart function, and associates with decreased cardiac cell apoptosis in response to WD.

67O Quantifying poly(ADP-Ribose) polymerase (PARP1) in vivo using a non-invasive PARP1 PET tracer

Robust non-invasive biomarker assays are needed to improve patient selection and pharmacodynamic assessments for PARP inhibitors as the currently accepted biomarkers (e.g. BRCA1/2 mutations) results in variability in response and benefit. [18F] Fluorthanatrace (FTT) is a positron emission tomography (PET) tracer that has been previously demonstrated to measure in vivo PARP1 expression in breast and ovarian cancers.

EP14.05-008 Development of a Prognostic Model for High-Grade Neuroendocrine Carcinoma of the Lung Using Next-Generation Sequencing

The high-grade neuroendocrine carcinoma (HGNEC) of the lung, small cell lung cancer (SCLC), and large cell neuroendocrine carcinoma (LCNEC), remain fatal due to lack of new therapeutic options and prognostic milestone to guide efficient treatment. We aim to explore the prognostic value of genetic aberration and PARP expression of HGNEC and to establish a novel prognostic model.

Intranasal Insulin Attenuates the Long-Term Adverse Effects of Neonatal Hyperglycemia on the Hippocampus in Rats

Hyperglycemia due to relative hypoinsulinism is common in extremely preterm infants and is associated with hippocampus-mediated long-term cognitive impairment. In neonatal rats, hypoinsulinemic hyperglycemia leads to oxidative stress, altered neurochemistry, microgliosis, and abnormal synaptogenesis in the hippocampus. Intranasal insulin (INS) bypasses the blood-brain barrier, targets the brain, and improves synaptogenesis in rodent models, and memory in adult humans with Alzheimer’s disease or type 2 diabetes, without altering the blood levels of insulin or glucose. To test whether INS improves hippocampal development in neonatal hyperglycemia, rat pups were subjected to hypoinsulinemic hyperglycemia by injecting streptozotocin (STZ) at a dose of 80 mg/kg i.p. on postnatal day (P) 2 and randomized to INS, 0.3U twice daily from P3-P6 (STZ + INS group), or no treatment (STZ group). The acute effects on hippocampal neurochemical profile and transcript mRNA expression of insulin receptor (Insr), glucose transporters (Glut1, Glut4, and Glut8), and poly(ADP-ribose) polymerase-1 (Parp1, a marker of oxidative stress) were determined on P7 using in vivo ¹H MR spectroscopy (MRS) and qPCR. The long-term effects on the neurochemical profile, microgliosis, and synaptogenesis were determined at adulthood using ¹H MRS and histochemical analysis. Relative to the control (CONT) group, mean blood glucose concentration was higher from P3 to P6 in the STZ and STZ + INS groups. On P7, MRS showed 10% higher taurine concentration in both STZ groups. qPCR showed 3-folds higher Insr and 5-folds higher Glut8 expression in the two STZ groups. Parp1 expression was 18% higher in the STZ group and normal in the STZ + INS group. At adulthood, blood glucose concentration in the fed state was higher in the STZ and STZ + INS groups. MRS showed 59% higher brain glucose concentration and histochemistry showed microgliosis in the hippocampal subareas in the STZ group. Brain glucose was normal in the STZ + INS group. Compared with the STZ group, phosphocreatine and phosphocreatine/creatine ratio were higher, and microglia in the hippocampal subareas fewer in the STZ + INS group (p < 0.05 for all). Neonatal hyperglycemia was associated with abnormal glucose metabolism and microgliosis in the adult hippocampus. INS administration during hyperglycemia attenuated these adverse effects and improved energy metabolism in the hippocampus.

Anti-Tumor Effect of Heat-Killed Bifidobacterium bifidum on Human Gastric Cancer through Akt-p53-Dependent Mitochondrial Apoptosis in Xenograft Models.

Paraprobiotics, inactivated microbial cells, regulate immune system and exhibit antioxidant and anti-inflammatory activities in patients with weakened immunity or the elderly. This study evaluated the anti-tumor effects of heat-killed Bifidobacterium and Lactobacillus on human gastric cancer MKN1 cells in vitro and in vivo in xenograft animal models. First, cytotoxicity and apoptosis in MKN1 cells of 11 different heat-killed Bifidobacterium or Lactobacillus strains were examined using the MTT assay or flow cytometry, respectively. Then, BALB/c nude mice xenograft animal models were implanted with human gastric cancer MKN1 cells and orally administered a selected single or a mixture of heat-killed bacterial strains to investigate their inhibitory effect on tumor growth. In addition, the expression of p-Akt, p53, Bax, Bak, cleaved caspase-9, -3, and PARP in the tumor tissues was analyzed using Western blotting assay or immunohistochemistry staining. The results show that heat-killed B. bifidum MG731 (MG731), L. reuteri MG5346 (MG5346), and L. rhamnosus MG5200 (MG5200) induced relatively greater apoptosis than other strains in MKN1 cells. Oral administration of a single dose or a mixture of MG731, MG5346, or MG5200 significantly delayed tumor growth, and MG731 had the most effective anti-tumor effect in the xenograft model. Protein expression of p-Akt, p53, Bax, cleaved caspase-3 and -9, and PARP in tumors derived from the xenograft model correlated with the results of the immunohistochemistry staining.

Ozonation process causes changes in PARP-1 expression and the metabolism of NADPH in strawberry fruit during storage

In this study, the effect of ozonation process on the poly(ADP-ribose) polymerase 1 gene expression (PARP-1) and related the NADPH metabolism in strawberry fruit during storage was determined. Our results showed that ozonation with gas at both 10 and 100 ppm concentrations increased the expression of PARP-1 in the fruit during storage. Furthermore, the ozonation process initially increased the level of NAD+ and NADH in the fruit, which corresponds to a higher ATP level. The storage of the fruit in an ozone atmosphere also contributed to increased activity of the NAD+ kinase, leading to increased levels of NADP+ . In turn, the higher activity of glucose-6-phosphate dehydrogenase caused the ozonated fruit to show a higher level of NADPH. However, as the storage period extended and thus with increasing expression of PARP-1 in the ozonated fruit, the level of NAD+ decreased. In general, the ozonated fruit, which had a higher level of NADPH, showed a higher content of reduced glutathione, which in turn contributed to an increase in the antioxidant activity of the fruit and, ultimately, to a lower accumulation of reactive oxygen species.

MicroRNA-8126-Mediated Antioxidant Stress Attenuates Isoflurane-Induced Hippocampal Neurotoxicity in Developing Rats.

Objective To investigate the effect of microRNA-8126 (miR-8126) on isoflurane-induced hippocampal neurotoxicity in rats. Methods A rat isoflurane nerve injury model was constructed. The expression of miR-8126 in the hippocampal region of normal and injured rats was measured by qRT-PCR; synaptic density protein-95, PAK-3 (p21-activated kinase-3) and apoptosis-related proteins cytochrome C, cleaved caspase-3, and cleaved PARP were detected by Western blot. The Cytochrome C, cleaved-caspase-3, and cleaved PARP expression was detected by WB, as well as GSH-Px, CAT, SOD, and ROS. Results miR-8126 was lowly expressed in the isoflurane-treated rat hippocampal region and in rat hippocampal neuronal cells, and the expression of apoptosis-related proteins and apoptosis levels were significantly increased, and neural activity, cell activity, and proliferation capacity were significantly decreased. Oxidative stress levels and ROS content were significantly increased; overexpression of miR-8126 in the rat hippocampal region significantly inhibited oxidative stress and apoptosis. Overexpression of miR-8126 in rat hippocampal neural progenitor cells significantly increased cell activity, proliferative capacity, and significantly smaller mitochondrial size and it decreased ROS content and oxidative stress levels and apoptosis-related protein expression compared to isoflurane-treated cells; while inhibition of miR-8126 expression in rat hippocampal neuronal cells significantly decreased cell activity, proliferative capacity, and mitochondrial size compared to the control group. In contrast, inhibition of miR-8126 expression in rat hippocampal neuronal cells resulted in a further decrease in cell activity, proliferation capacity, and significantly larger mitochondrial size and increased expression of apoptosis-related proteins compared with the control group. miR-8126 regulates the activity of rat hippocampal neuronal cells by targeting ATF4. Conclusions miR-8126 attenuates isoflurane-induced hippocampal neurotoxicity in rats by mediating antioxidative stress.

Small Cell and Other Rare Histologic Types of Cervical Cancer.

The goal of this paper was to summarize the recent evidence on rare subtypes of cervical cancer including small-cell carcinoma of the cervix (SCCC), gastric-type adenocarcinoma, and carcinosarcoma. All three cervical cancer subtypes are aggressive with poor treatment response and high recurrence rates. Molecular studies have identified various actionable mutations in both SCCC (PIK3CA, MYC, TP53, PTEN, ARID1A, KRAS, BRCA2) and gastric-type adenocarcinoma (KRAS, ARID1A, PTEN). While there are a limited number of case reports demonstrating a favorable response for recurrent SCCC to immune checkpoint inhibitors, a larger case series failed to show benefit. The checkpoint inhibitors role in gastric-type adenocarcinoma and carcinosarcoma is yet to be determined. Ninety-one percent of SCCC cases show PARP expression, suggesting a possible role for PARP inhibitors; however, this has yet to be examined in future clinical trials. More studies are needed, with a focus on targeted therapies. The role of PARP inhibitors in SCCC is potentially promising, but significant collaboration between centers/groups will be required to achieve this.

Pharmacologic inhibition of discoidin domain Receptor 2 (DDR2) sensitizes homologous recombination proficient ovarian cancer models to treatment with olaparib (245)

Pharmacologic inhibition of discoidin domain Receptor 2 (DDR2) sensitizes homologous recombination proficient ovarian cancer models to treatment with olaparib (245)

YY1 alleviates lupus nephritis-induced renal injury by reducing the Th17/Treg cell ratio via the IFN-γ/Fra2 axis

AbstractLupus nephritis (LN) is associated with extensive injury and nephron loss in the afflicted kidney. Evidence has revealed the involvement of dysregulated Yin Yang 1 (YY1), a reported inflammatory modulator, in LN-induced kidney injury, and our microarray profile identified downregulated YY1 expression. Therefore, this study explored the functional relevance and mechanism of YY1 in LN-induced kidney injury. LN was modeled in mice by intraperitoneal injection of pristane, and Jurkat cells (CD41 human T lymphocytes) were activated with TNF-α to mimic the inflammatory environment found in LN. The expression patterns of YY1 and bioinformatics predictions of the downstream factor IFN-γ were confirmed in renal tissues from the mice with LN using qRT-PCR and Western blot analyses. The contents of proinflammatory cytokines in mouse serum samples and cell supernatants were determined using enzyme-linked immunosorbent assays (ELISAs). Ectopic expression and depletion approaches were subsequently used in vitro and in vivo to examine the effects of the YY1/IFN-γ/Fra2/PARP-1/FOXO1 axis on TNF-α-induced inflammation and LN-induced kidney injury. The results showed downregulated expression of YY1 and FOXO1 in the kidney tissues of the mice with LN. Increased proinflammatory factor production was observed in the mice with LN and TNF-α-treated Jurkat cell supernatant, accompanied by increased cell apoptosis and a high ratio of Th17/Treg cells, and these effects were reversed by YY1 restoration. YY1 was further shown to inhibit IFN-γ expression and thereby downregulate Fra2 expression. Fra2 depletion then inhibited PARP-1 expression and promoted FOXO1 expression to suppress cell apoptosis and the release of inflammatory factors. Collectively, our findings revealed that YY1 may alleviate LN-induced renal injury via the IFN-γ/Fra2/PARP-1/FOXO1 axis.

Epithelial tumor compartment- and adjacent stromal compartment-specific expression of PARP1 in different anatomical sites in patients with HGSOC

High-grade serous ovarian carcinoma (HGSOC) is responsible for the majority of ovarian cancer-associated deaths. PARP (poly-(ADP-ribose) polymerase) inhibitors (PARPi) (olaparib, rucaparib and niraparib) have been approved in recent years to be used in both the frontline setting as maintenance therapy and in the recurrent setting for patients with ovarian cancer (OC). Previous studies have reported an increased expression of PARP1, a sensor for DNA damage, in OC; however, its compartment (epithelial tumor vs stroma)-, anatomical site (fallopian tube, omentum, ovary and serous tubal in situ carcinoma)- and histotype-specific expression have not been studied. Here, we showed that PARP1 protein levels are higher in epithelial tumors compared to adjacent non-malignant stroma at four different anatomical locations in HGSOC, with the most significant difference in PARP1 levels in omental metastases. Furthermore, we found that PARP1 protein levels are elevated in tumors relative to normal tissue in the fallopian tube, omentum and ovary in patients with HGSOC, again with the most significant difference in the omentum. We also showed that PARP1 expression is increased in a malignant and invasive stage in mouse ovarian surface epithelium cells, and that PARP1 mRNA levels are lower in mucinous histotype compared to serous histotype of epithelial OC. These findings indicate that a better understanding of compartment-, anatomical location- and histotype-specific changes in PARP1 levels in OC is needed since PARP inhibitors are currently being used in the treatment of patients with OC.

Cadmium exposure induces pyroptosis in testicular tissue by increasing oxidative stress and activating the AIM2 inflammasome pathway

High doses of cadmium (Cd) cause irreversible injury to the reproductive system, especially testicular tissue. Studies have shown that pyroptosis is involved in Cd-induced tissue damage, but whether pyroptosis is involved in damage to testicular tissue following Cd exposure remains unclear. To investigate the mechanism of pyroptosis in testicular injury induced by Cd exposure, we used 8-week-old male C57BL/6J mice subjected to consecutive 7 days of intraperitoneal injection of cadmium chloride (CdCl2) at concentrations of 0, 1.0 and 3.0 mg/kg. The results indicated that 3.0 mg/kg CdCl2 significantly decreased serum testosterone levels, sperm concentration and sperm motility, while increased LDH and IL-1β levels. Testicular HE staining indicated that Cd exposure damaged the interstitial cells and increased the atypical residual bodies. Fluorescence results indicated that 3.0 mg/kg CdCl2 increased ROS levels, DNA damage, and the number of TUNEL-positive seminiferous tubule cells in testicular tissue. Transcriptome analysis showed that Cd exposure mainly induced inflammatory and chemokine signaling pathways in testicular tissue, with upregulated mRNA levels of Aim2, and reduced mRNA levels of Nlrp3. Further analysis showed that 3.0 mg/kg CdCl2 increased the expression of testicular HO-1, SOD2, γH2AX and PARP-1, as well as the pyroptosis-related factors GSDMD, GSDME, Caspase-1, ASC and IL-1β. In conclusion, our results provide a possible mechanism by which Cd exposure activates the AIM2 pathway by increasing oxidative stress injury to induce pyroptosis in testicular tissue. This provides a new perspective on testicular damage caused by Cd exposure.

Anti-glioblastoma activity of monensin and its analogs in an organoid model of cancer

Glioblastoma (GBM) remains the most frequently diagnosed primary malignant brain cancer in adults. Despite recent progress in understanding the biology of GBM, the clinical outcome for patients remains poor, with a median survival of approximately one year after diagnosis. One factor contributing to failure in clinical trials is the fact that traditional models used in GBM drug discovery poorly recapitulate patient tumors. Previous studies have shown that monensin (MON) analogs, namely esters and amides on C-26 were potent towards various types of cancer cell lines. In the present study we have investigated the activity of these molecules in GBM organoids, as well as in a host:tumor organoid model. Using a mini-ring cell viability assay we have identified seven analogs (IC50 = 91.5 ± 54.4–291.7 ± 68.8 nM) more potent than parent MON (IC50 = 612.6 ± 184.4 nM). Five of these compounds induced substantial DNA fragmentation in GBM organoids, suggestive of apoptotic cell death. The most active analog, compound 1, significantly reduced GBM cell migration, induced PARP degradation, diminished phosphorylation of STAT3, Akt and GSK3β, increased ɣH2AX signaling and upregulated expression of the autophagy associated marker LC3-II. To investigate the activity of MON and compound 1 in a tumor microenvironment, we developed human cerebral organoids (COs) from human induced pluripotent stem cells (iPSCs). The COs showed features of early developing brain such as multiple neural rosettes with a proliferative zone of neural stem cells (Nestin+), neurons (TUJ1 +), primitive ventricular system (SOX2 +/Ki67 +), intermediate zone (TBR2 +) and cortical plate (MAP2 +). In order to generate host:tumor organoids, we co-cultured RFP-labeled U87MG cells with fully formed COs. Compound 1 and MON reduced U87MG tumor size in the COs after four days of treatment and induced a significant reduction of PARP expression. These findings highlight the therapeutic potential of MON analogs towards GBM and support the application of organoid models in anti-cancer drug discovery.

Lithocholic Acid Alleviates Deoxynivalenol-Induced Lethal Cholesterol Metabolic Abnormalities in IPI-2I Cells.

Deoxynivalenol (DON) is a secondary metabolite of fungi. Ingestion of feed containing DON causes severe intestinal damage in humans and animals, possibly due to cholesterol-enriched lipid raft abnormalities. Cholic acid (CA) and lithocholic acid (LCA) are metabolites of cholesterol transformation, which have been proven to benefit epithelial cell proliferation and reduce intestinal inflammation and lesions. Therefore, we aimed to study the protective roles of CA and LCA administration on the DON-exposed intestinal epithelial cells (IPI-2I) and the underlying mechanisms involved in cholesterol metabolism. We found that LCA pretreatment, but not CA, alleviated the reduction of cell numbers caused by DON exposure. Furthermore, we demonstrate that LCA restored the DON-induced cell apoptosis by reducing the cleaved caspase 3 and cleaved PARP-1 expression. DON-increased cellular cholesterol and bile acid contents were significantly reduced when LCA was co-treated. Further transcriptomic analysis revealed that the aberrant cholesterol homeostasis genes profile was observed in the cells exposed to DON or pretreated with LCA. We also validated that the key genes involved in cholesterol biosynthesis and transformation (cholesterol to bile acids) were strongly inhibited by the LCA treatment in the DON-exposed cells. Together, this study demonstrated that LCA ameliorated DON-caused toxic apoptosis in IPI-2I cells by maintaining cholesterol metabolism. We suggest that as an endogenous metabolite, LCA may be used as a therapeutic and/or integrated into a dietary intervention against mycotoxin toxicity.

High Expression of PARP1 in Tumor and Stroma Cells Predicts Different Prognosis and Platinum Resistance in Patients With Advanced Epithelial Ovarian Cancer.

ObjectiveThis study aimed to explore the roles of PARP1 mRNA and protein expression in platinum resistance and prognosis of EOC patients, and reveal the different roles of PARP1 protein in epithelial tumor and stroma cells.MethodsThe PARP1 mRNA expression of the EOC tissues was examined by RT-qPCR. The impacts of PARP1 expression on prognosis were measured by Kaplan-Meier and Cox regression. Receiver operating characteristic (ROC) curve analysis was employed for calculating the diagnostic value of PARP1 on platinum resistance. The microarray of formalin-fixed, paraffin-embedded (FFPE) tissues was processed for multiplex immunofluorescence to detect the protein levels of PARP1 and cytokeratin (CK).ResultsThe PARP1mRNA expression of EOC patients was higher in the platinum-resistant group compared with the sensitive group (P<0.01). Kaplan-Meier analysis demonstrated that high PARP1 mRNA expression was associated with poor survival of EOC patients. In Cox regression analyses, high PARP1 mRNA expression independently predicted poor prognosis (P=0.001, HR=2.076, 95%CI=1.373-3.140). The area under the ROC curve of PARP1 mRNA for predicting the platinum resistance in EOC patients was 0.649, with a sensitivity of 0.607 and specificity of 0.668. Furthermore, the protein expression of PARP1 was higher in the platinum-resistant group than in the sensitive group (P<0.01) and associated with a worse prognosis. Additionally, according to CK labeling, we observed that enhanced expression of PARP1 in the CK+ region was associated with platinum resistance and lower survival, but in CK- region, it predicted a good prognosis and platinum sensitivity.Conclusion PARP1 may be a potential biomarker to predict platinum resistance and prognosis for EOC patients, exerting different roles on epithelial tumor and stromal cells.