Chronic exposure to arsenic promotes lung cancer. Human studies have identified immunosuppression as a risk factor for cancer development. The immune checkpoint pathway of Programmed cell death 1 ligand (PD-L1) and its receptor (programmed cell death receptor 1, PD-1) is the most studied mechanism of immunosuppression. We have previously shown that prolonged arsenic exposure induced cell transformation of BEAS-2B cells, a human lung epithelial cell line. More recently our study further showed that arsenic induced PD-L1 up-regulation, inhibited T cell effector function, and enhanced lung tumor formation in the mice. In the current study, using arsenic-induced BEAS-2B transformation as a model system we investigated the mechanism underlying PD-L1 up-regulation by arsenic. Our data suggests that Lnc-DC, a long non-coding RNA, and signal transducer and activator of transcription 3 (STAT3) mediates PD-L1 up-regulation by arsenic.

We have recently described a novel guanidinium-based compound, VP79s, which induces cytotoxicity in various cancer cell lines. Here, we aim to investigate the activity of VP79s and associated mechanisms of action in multiple myeloma (MM) cells in vitro and ex vivo.

To analyze the effect of the use of carvacrol in the cardiovascular system of spontaneously hypertensive rats (SHR).

Drug resistance remains a major challenge in the current treatment of acute myeloid leukemia (AML). Finding specific molecules responsible for mediating drug resistance in AML contributes to the effective reversal of drug resistance. Recent studies have found that mitogen- and stress-activated protein kinase 1 (MSK1) is of great significance in the occurrence and development of tumors. In the current study, MSK1 was found highly expressed in drug-resistant AML patients. Heme oxygenase-1 (HO-1) has been previously validated to be associated with drug resistance in AML. Our study revealed a positive correlation between MSK1 and HO-1 in patient samples. In vitro experiments revealed that the sensitivity of AML cell lines THP-1 and U937 to cytarabine (Ara-C) significantly decreased after overexpression of MSK1. Meanwhile, downregulation of MSK1 by siRNA transfection or treatment of pharmacological inhibitor SB-747651A in AML cell lines and primary AML cells enhanced the sensitivity to Ara-C. Flow cytometry analysis showed that downregulation of MSK1 in AML cells accelerated apoptosis and arrested cell cycle progression in G0/G1 phase. However, the increased cell sensitivity induced by MSK1 downregulation was reversed by the induction of HO-1 inducer Hemin. Through further mechanism exploration, real-time PCR, immunofluorescence and Western blot analysis demonstrated that brahma related gene 1 (BRG1) was involved in the regulatory effect of MSK1 on HO-1. High expression of MSK1 could promote the resistance of AML through BRG1-mediated upregulation of HO-1. Downregulation of MSK1 enhanced the sensitivity of AML cells to Ara-C. Our findings provide novel ideas for developing effective anti-AML targets.

Aging and common diseases alter the stiffness of bone tissue, causing changes to the microenvironment of the mechanosensitive bone cells. Osteoclasts, the sole bone-resorbing cells, play a vital role in bone remodeling. This study was performed to elucidate the mechanism through which osteoclasts sense and react to substrate stiffness signals.

More than a decade after the launch of DNA methyltransferase and histone deacetylase inhibitors for the treatment of cancer, 2020 heralded the approval of the first histone methyltransferase inhibitor, revitalizing the concept that targeted manipulation of the chromatin regulatory landscape can have profound therapeutic impact. Three chromatin regulatory pathways-DNA methylation, histone acetylation and methylation-are frequently implicated in human cancer but hundreds of potentially druggable mechanisms complicate identification of key targets for therapeutic intervention. In addition to human genetics and functional screening, chemical biology approaches have proven critical for the discovery of key nodes in these pathways and in an ever-increasing complexity of molecularly defined human cancer contexts. This review introduces small molecule targeting approaches, showcases chemical probes and drug candidates for epigenetic writer enzymes, illustrates molecular features that may represent epigenetic dependencies and suggests translational strategies to maximize their impact in cancer therapy.

Human γδ T cells expressing Vγ9Vδ2 T cell receptors exert a robust response to pathogens and malignant cells. These cells are activated by BTN3A1, which is expressed by pathogen-derived phosphoantigens (pAgs) or host-derived pAgs that accumulate in transformed cells or in cells exposed to aminobisphosphonates. Activated Vδ2 (+) T cells exert multiple effector functions; therefore, they are a promising candidate for immunotherapy. However, not all donors have γδ T cells with adequate proliferative activity. Here, we performed ex vivo culture of γδ T cells from 20 healthy donors and explored factors that may affect their expansion efficiency. Consistent with previous studies, we found that amplification of γδ T cells requires CD14+ monocytes to act as accessory cells. We also show here that surface expression of BTN3A1 by monocytes correlates positively with γδ T cell expansion. Moreover, treatment with BTN3A1-Fc increased the expansion efficiency of peripheral blood mononuclear cells (PBMCs) from donors harboring γδ T cells with poor expansion capacity. Taken together, the data suggest that the level of BTN3A1 expressed on the surface of monocytes is a useful biomarker for predicting the degree of expansion of γδ T cells.

Small-molecule kinase inhibitors represent a major group of cancer therapeutics, but tumor responses are often incomplete. To identify pathways that modulate kinase inhibitor response, we conducted a genome-wide knockout (KO) screen in glioblastoma cells treated with the pan-ErbB inhibitor neratinib. Loss of general control nonderepressible 2 (GCN2) kinase rendered cells resistant to neratinib, whereas depletion of the GADD34 phosphatase increased neratinib sensitivity. Loss of GCN2 conferred neratinib resistance by preventing binding and activation of GCN2 by neratinib. Several other Food and Drug Administration (FDA)-approved inhibitors, such erlotinib and sunitinib, also bound and activated GCN2. Our results highlight the utility of genome-wide functional screens to uncover novel mechanisms of drug action and document the role of the integrated stress response (ISR) in modulating the response to inhibitors of oncogenic kinases.

Apoptosis of alveolar epithelial cells during acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical pathological event that seriously endangers the health of patients. Suppressing apoptosis of alveolar epithelial cells was shown to alleviate functional damage of lung, and modulator of the reactive oxygen species (ROS)-induced apoptosis becomes a promising approach to the ALI therapy. Previous little studies showed that DHCR24 possessed anti-oxidative and anti-apoptotic property in ALI. Thus, H2O2 was utilized to mimic oxidative damage in vitro in alveolar epithelial cell line A549 in the present study. Our results exhibited that H2O2 treatment of A549 cells reduced the level of SOD and increased the level of ROS. Moreover, H2O2 inhibited Bcl-2 expression in A549 cells, but increased Bax and the activity of Caspase-3. In addition, the apoptosis rate in the H2O2 treatment group also increased significantly. And the expression of 24-dehydrocholesterol reductase (DHCR24) was markedly reduced in the H2O2 treatment group. Overexpression of DHCR24 can remarkably inhibit H2O2-induced oxidative stress and apoptosis. We found that overexpression of DHCR24 increased the phosphorylation level of PI3K and AKT, however, the PI3K inhibitor LY294002 (LY) eliminated the protective effect of DHCR24 in ALI. DHCR24 was down-regulated in H2O2-induced ALI, and overexpression of DHCR24 could inhibit H2O2-induced oxidative stress and apoptosis of A549 cells by activating the Phosphatidylinositol-3-Kinase/Protein Kinase B (PI3K/AKT) signaling pathway. The above exhibited a protective effect of DHCR24 on alveolar epithelial cells exposed to oxidative stress-mediated apoptosis and provided a novel therapeutic method for ALI.

Necroptosis is a form of regulated programmed cell death that is mediated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting serine/threonine protein kinase-3 (RIPK3), and mixed lineage kinase domain-like protein (MLKL); however, it is not known whether zinc finger protein 91 (ZFP91) is involved in this process. Here, we investigated ZFP91 as a potential mediator of necroptosis. Our mechanistic study demonstrates that ZFP91 promotes RIPK1-RIPK3 interaction, thereby stabilizing the RIPK1 and RIPK3 proteins and facilitating necroptosis. ZFP91 stabilized RIPK1 to promote cell death by inducing RIPK1 de-ubiquitination. ZFP91 also significantly increased production of mitochondrial reactive oxygen species (ROS). Accumulation of ROS promoted RIPK3-independent necroptosis triggered by tumor necrosis factor (TNF). in vivo, ZFP91 knockdown alleviated TNFα-induced systemic inflammatory response syndrome (SIRS). These results provide direct evidence that ZFP91 plays an important role in the initiation of RIPK1/RIPK3-dependent necroptosis in vitro and in vivo. We discussed the potential of ZFP91 as a novel therapeutic target for necroptosis-associated diseases.

Regulating immune homeostasis by targeting liver macrophage polarization is a potential therapeutic strategy for hepatic fibrosis. Chitooligosaccharide (COS) is a bioactive oligosaccharide possessing potent immunomodulatory and hepatoprotective effects. In this study the hepatoprotective effect of COS on hepatic fibrosis was examined in mice and the underlying mechanisms were investigated. Herein, mice were induced to hepatic fibrosis using carbon tetrachloride (CCl4) and concurrently treated with COS orally. Kupffer cells (KCs) were skewed towards M1 macrophage polarization by lipopolysaccharide (LPS) and towards M2 macrophage polarization by interleukin-4 (IL-4) in vitro, which were utilized for COS treatment. The results showed that mice were rescued from hepatic fibrosis by COS, marked by a reduction in the deposition of the extracellular matrix (ECM) and histological lesions. COS had an inhibitory effect on the polarization of M1 and M2 macrophages both in vivo and in vitro, characterized by the raised biomarker of the M1 and M2 macrophages slipping towards the basal levels. Furthermore, COS inhibited the JAK2/STAT1 pathways on M1 macrophages and the JAK1/STAT6 pathways on M2 macrophages in KCs. In summary, this study revealed a molecular mechanism for the impact of COS effectiveness on the polarization of liver macrophages, suggesting that is could be a possible intervention for hepatic fibrosis.

Cervical cancer (CC) ranks as the second most frequent tumor in women, and CC stem cells have been vital in the tumorigenesis of CC. Recently, the metastasis- associated in colon cancer 1 (MACC1) gene was proven to be a promising biomarker of CC. However, the role and mechanism of MACC1 in CC remain undetermined. Expressions of MACC1 were estimated by qRT-PCR, immunohistochemistry, and Western blot assays in cervical cancer tissues and cells. Three siRNAs were generated to knockdown expressions of MACC1 in CC cells. After knockdown of MACC1 or/and Colivelin treatment, cell migration, invasion, apoptosis, and stemness were evaluated through a series of functional experiments including Transwell, flow cytometry, Hoechst staining, and sphere-formation assays. MACC1 was found to express more highly in CC tissues in comparison with corresponding non-tumor tissues at both mRNA and protein levels. Functionally, the knocking- down of MACC1 significantly repressed migration and invasion, and induced apoptosis of CC cells. Also, knockdown of MACC1 was discovered to suppress sphere-formation of CC cells and downregulate OCT4 and Nanog. It was proved that knockdown of MACC1 had a significant blocking effect on the AKT/STAT3 pathway. In addition, we verified that treatment with the STAT3 activator (Colivelin) had significant reversal effects on the malignant behaviors of CC cells and CC stemness. Our study concluded that MACC1 might be a novel regulator of CC by regulating the AKT/STAT3 pathway to change the migration, invasion, apoptosis, and cancer stemness of CC cells.

Two series of quinoline-thiazole and quinoline-thiazolidinone hybrids were designed, synthesized, and evaluated for their in vitro antitumor activity on MCF-7 breast cancer cell line. In comparison with lapatinib (IC50  = 4.69 µM), compounds 4b and 6b exhibited the best antiproliferative activity with IC50 values of 33.19 and 5.35 µM, respectively. Although compound 6b showed higher cytotoxicity, compound 4b exhibited better inhibitory activity toward the epidermal growth factor receptor (EGFR) pathway than compound 6b as represented by the significant reduction in the EGFR kinase activity and the levels of phosho-EGFR and phosho-AKT when compared to lapatinib as a reference standard. Moreover, compound 4b was capable of down-regulating the anti-apoptotic genes Bcl-2 and survivin and up-regulating the level of the pro-apoptotic gene BAX. Molecular modeling study was carried out to predict the binding interactions of both compounds into the target kinase. Finally, the physicochemical properties were investigated in silico as well.

Uncoupling protein 1 (UCP1) in brown or beige adipocytes is a mitochondrial protein that is expected to enhance whole-body energy expenditure. For the high-throughput screening of UCP1 transcriptional activity regulator, we established a murine inguinal white adipose tissue-derived Ucp1-luciferase reporter preadipocyte line. Using this reporter preadipocyte line, 654 flavor compounds were screened, and a novel Ucp1 expression-inducing compound, 5-methylquinoxaline, was identified. Adipocytes treated with 5-methylquinoxaline showed increased Ucp1 mRNA expression levels and enhanced oxygen consumption. 5-Methylquinoxaline induced Ucp1 expression through peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), and 5-methylquinoxaline-induced PGC1α activation seemed to be partially regulated by its phosphorylation or deacetylation. Thus, our Ucp1-luciferase reporter preadipocyte line is a useful tool for screening of Ucp1 inductive compounds.

Baicalein is a flavonoid extracted from the root of Scutellaria baicalensis (Chinese skullcap) and is consumed as part of this botanical dietary supplement to reduce oxidative stress, pain, and inflammation. We previously reported that baicalein can also modify receptor signaling through the progesterone receptor (PR) and glucocorticoid receptor (GR) in vitro, which is interesting due to the well-established roles of both PR and GR in reducing inflammation. To understand the effects of baicalein on PR and GR signaling in vivo in the uterus, ovariectomized CD-1 mice were treated with DMSO, progesterone (P4), baicalein, P4 with baicalein, and P4 with RU486, a PR antagonist, for a week. The uteri were collected for histology and RNA sequencing. Our results showed that baicalein attenuated the antiproliferative effect of P4 on luminal epithelium as well as on the PR target genes HAND2 and ZBTB16. Baicalein did not change levels of PR or GR RNA or protein in the uterus. RNA sequencing data indicated that many transcripts significantly altered by baicalein were regulated in the opposite direction by P4. Similarly, a large portion of GO/KEGG terms and GSEA gene sets were altered in the opposite direction by baicalein as compared to P4 treatment. Treatment of baicalein did not change body weight, organ weight, or blood glucose level. In summary, baicalein functioned as a PR antagonist in vivo and therefore may oppose P4 action under certain conditions such as uterine hyperplasia, fibroids, and uterine cancers.

Persistent pulmonary hypertension of the newborn (PPHN) is a common pulmonary vascular disease during the neonatal period, and it is associated with a high clinical mortality rate and a poor prognosis. At present, the treatment of PPHN is based mainly on inhaled nitric oxide (iNO), high‑frequency ventilation, and pulmonary vasodilators. Sildenafil has gradually begun to be used in recent years for the treatment of PPHN and has exhibited some success; however, its detailed mechanism of action requires further elucidation. An animal model of neonatal pulmonary hypertension (neonatal rats, 48 h after birth, 10% O2, 14 days) as well as a cell model [human pulmonary artery smooth muscle cells (PASMCs), 4% O2, 60 h] were established. The effects of sildenafil on pulmonary hypertension in neonatal rats were evaluated by hematoxylin and eosin staining, immunofluorescence analysis, western blotting and PCR, and the changes in peroxisome proliferator‑activated receptor γ (PPARγ), transient receptor potential canonical (TRPC)1, TRPC6 and Ki67 expression levels were detected under hypoxic conditions. The results revealed that sildenafil reversed the increases in the right ventricular mean pressure and right ventricular hypertrophy index induced by hypoxia, and attenuated pulmonary arterial remodeling as well as PASMC proliferation. The inhibitory effects of sildenafil on TRPC expression and PASMC proliferation were attenuated by GW9662 and PPARγ small interfering RNA. In conclusion, sildenafil protects against hypoxia‑induced pulmonary hypertension and right ventricular hypertrophy in neonatal rats by upregulating PPARγ expression and downregulating TRPC1 and TRPC6 expression.

Histone deacetylase inhibitors (HDACi) sensitize homologous recombination (HR)-proficient human ovarian cancer cells to PARP inhibitors (PARPi). To investigate mechanisms of anti-tumor effects of combined HDACi/PARPi treatment we performed transcriptome analysis in HR- proficient human ovarian cancer cells and tested drug effects in established immunocompetent mouse ovarian cancer models. Human SKOV-3 cells were treated with vehicle (Con), olaparib (Ola), panobinostat (Pano) or Pano+Ola and RNA-seq analysis performed. DESeq2 identified differentially expressed HR repair and immune transcripts. Luciferised syngeneic mouse ovarian cancer cells (ID8-luc) were treated with the HDACi panobinostat alone or combined with olaparib and effects on cell viability, apoptosis, DNA damage and HR efficiency determined. C57BL/6 mice with intraperitoneally injected ID8-luc cells were treated with panobinostat and/or olaparib followed by assessment of tumor burden, markers of cell proliferation, apoptosis and DNA damage, tumor-infiltrating T cells and macrophages, and other immune cell populations in ascites fluid. There was a significant reduction in expression of 20/37 HR pathway genes by Pano+Ola, with immune and inflammatory-related pathways also significantly enriched by the combination. In ID8 cells, Pano+Ola decreased cell viability, HR repair, and enhanced DNA damage. Pano+Ola also co-operatively reduced tumor burden and proliferation, increased tumor apoptosis and DNA damage, enhanced infiltration of CD8+ T cells into tumors, and decreased expression of M2-like macrophage markers. In conclusion, panobinostat in combination with olaparib targets ovarian tumors through both direct cytotoxic and indirect immune-modulating effects.

Cancer cell proliferation in some organs often depends on conversion of pyruvate to oxaloacetate via pyruvate carboxylase (PC) for replenishing the tricarboxylic acid cycle to support biomass production. In this study, PC was identified as the cellular target of erianin using the photoaffinity labeling-click chemistry-based probe strategy. Erianin potently inhibited the enzymatic activity of PC, which mediated the anticancer effect of erianin in human hepatocellular carcinoma (HCC). Erianin modulated cancer-related gene expression and induced changes in metabolic intermediates. Moreover, erianin promotes mitochondrial oxidative stress and inhibits glycolysis, leading to insufficient energy required for cell proliferation. Analysis of 14 natural analogs of erianin showed that some compounds exhibited potent inhibitory effects on PC. These results suggest that PC is a cellular target of erianin and reveal the unrecognized function of PC in HCC tumorigenesis; erianin along with its analogs warrants further development as a novel therapeutic strategy for the treatment of HCC.

Ferroptosis is a kind of cell death closely related to selective autophagy, such as ferritinophagy, lipophagy, clockophagy and chaperone-mediated autophagy. However, the role of reticulophagy, which specifically degrades endoplasmic reticulum (ER) fragments (also known as ER-phagy), in ferroptosis regulation is still unclear. In this study, we found that sorafenib (ferroptosis inducer) can effectively activate the receptor protein FAM134B-mediated ER-phagy, and FAM134B knockdown not only blocked ER-phagy but also significantly strengthened cellular sensitivity to ferroptosis without affecting macroautophagy. In vivo experiments also yielded similar results. These evidences provided new clues for ferroptosis regulation. Subsequently, bioinformatic analysis combined with RNA binding protein immunoprecipitation and polyribosome fractionation preliminarily indicated that PABPC1 can interact with FAM134B mRNA and promote its translation. Taken together, this study revealed the role of the PABPC1-FAM134B-ER-phagy pathway on ferroptosis, providing important evidence for novel anti-cancer strategies.

Estrogen signaling plays important roles in diverse physiological and pathophysiological processes. However, the relationship between estrogen signaling and epigenetic regulation is not fully understood. Here, we explored the effect of estrogen signaling on the expression of Ten-Eleven Translocation (TET) family genes and DNA hydroxylmethylation in estrogen receptor alpha positive (ERα+) breast cancer cells. By analyzing the RNA-seq data, we identified TET2 as an estradiol (E2)-responsive gene in ERα+ MCF7 cells. RT-qPCR and Western blot analyses confirmed that both the mRNA and protein levels of TET2 gene were upregulated in MCF7 cells by E2 treatment. ChIP-seq and qPCR analyses showed that the enrichment of ERα and H3K27ac on the upstream regulatory regions of TET2 gene was increased in MCF7 cells upon E2 treatment. Moreover, E2 treatment also led to a significant increase in the global 5-hydroxymethylcytosine (5hmC) level, while knockout of TET2 abolished such E2-induced 5hmC increase. Conversely, treatment with ICI 182780, a potent and selective estrogen receptor degrader (SERD), inhibited TET2 gene expression and down-regulated the 5hmC level in MCF7 cells. Taken together, our study identified an ERα/TET2/5hmC epigenetic pathway, which may participate in the estrogen-associated physiological and pathophysiological processes.