WTAP promotes proliferation of esophageal squamous cell carcinoma via m6A-dependent epigenetic promoting of PTP4A1.

Esophageal squamous cell carcinoma (ESCC) represents a frequently seen malignancy with high prevalence worldwide. Although current studies have shown that Wilms' tumor 1-associated protein (WTAP), a major part in the methyltransferase complex, is involved in various tumor pathological processes, its specific role in ESCC remains unclear. Therefore, the present work focused on exploring WTAP's function and mechanism in ESCC progression using clinical ESCC specimens, ESCC cells, and mammalian models. Firstly, we proved WTAP was significantly upregulated within ESCC, and WTAP mRNA expression showed a good diagnostic performance for ESCC. Functionally, WTAP positively regulated in-vivo and in-vitro ESCC cells' malignant phenotype through the AKT-mTOR signaling pathway. Meanwhile, WTAP positively regulated the N6-methyladenosine (m6A) modification levels in ESCC cells. Protein tyrosine phase type IVA member 1 (PTP4A1) was confirmed to be the m6A target of WTAP, and WTAP positively regulated the expression of PTP4A1. Further study revealed that PTP4A1 showed high expression within ESCC. Silencing PTP4A1 inhibited the AKT-mTOR signaling pathway to suppress ESCC cells' proliferation. Rescue experiments showed that silencing PTP4A1 partially reversed the WTAP-promoting effect on ESCC cells' proliferation ability. Mechanistically, WTAP regulated PTP4A1 expression to activate the AKT-mTOR pathway, promoting the proliferation of ESCC cells. Our study demonstrated that WTAP regulates the progression of ESCC through the m6A-PTP4A1-AKT-mTOR signaling axis and that WTAP is a potential target for diagnosing and treating ESCC.

Controlling the Crystal Growth of DNA Molecules via Strategic Chemical Modifications.

Intermolecular interactions are critical to the crystallization of biomolecules, yet the precise control of biomolecular crystal growth based on these interactions remains elusive. To understand the connections between the crystallization kinetics and the strength of intermolecular interactions, herein we have employed DNA triangular crystals and modified ones as a versatile tool to investigate how the strength of intermolecular interaction affects crystal growth. Interestingly, we have found that the 2'-O-methylation at sticky ends of the DNA triangle could strengthen its intermolecular interaction, resulting in the accelerated formation of smaller crystals. Conversely, phosphorothioate modification could weaken the sticky-end cohesion and delay the nucleation, resulting in formation of fewer but larger crystals. In addition, these modification effects were consistently observed in the crystallization of a DNA decamer. In one word, our experimental results demonstrate that the strength of intermolecular interaction directly impacts crystal growth. It suggests that 2'-O-methylation and phosphorothioate modification represents a rational strategy for controlling DNA molecules grow into desired crystals and it also facilitates structural determination.

Chloroquine Sensitizes Esophageal Carcinoma EC109 Cells to Paclitaxel by Inhibiting Autophagy.

As an autophagy inhibitor, chloroquine (CQ) showed anti-tumor effect on several types of cancer and paclitaxel (PTX) is widely used in the treatment of esophageal carcinoma patients, but chemoresistance remains a major hurdle for PTX application due to the cytoprotective autophagy. Therefore, the aim of this study was to investigate whether CQ could elevate the anti-tumor effect of PTX on esophageal carcinoma cell line EC109 and explore the potential molecular mechanisms. We confirmed the suppressive effect of PTX on EC109 by MTT, scratch test, transwell and soft agar assay. And, we detected the key proteins in Akt/mTOR pathway, as well as the autophagy marker LC3 and p62 through Western Blot. In addition, GFP-LC3 plasmid was transfected into EC109 cells to monitor the autophagosome after CQ and PTX treatment. Ultimately, we observed the alterations in the proliferation and colony formation abilities of EC109 after knocking down mTOR by shRNA. We confirmed PTX could suppress the proliferation, migration and colony formation (all P < 0.05) abilities of EC109, and CQ could sensitize the inhibition effect of PTX by inhibiting autophagy through Akt/mTOR pathway. Furthermore, inhibiting Akt/mTOR pathway initiated autophagy and enhanced the sensitivity of EC109 to CQ and PTX. In summary, we suggest CQ could be used as a potential chemosensitizer for PTX in esophageal carcinoma treatment.

TPP1 Inhibits DNA Damage Response and Chemosensitivity in Esophageal Cancer.

TPP1, as one of the telomere-protective protein complex, functions to maintain telomere stability. In this study, we found that TPP1 was significantly upregulated in esophageal cancer (EC). We found that the proliferation and migration ability were significantly inhibited, while the results of flow cytometry assay indicated that the growth was hindered in the G1 phase after TPP1 knockdown. However, the proliferative viability and migratory ability were reversed after TPP1 overexpression in EC cells. Then, we found a significant increase in ß-galactosidase positivity following TPP1 knockdown and the opposite following TPP1 overexpression in EC cells. Furthermore, TPP1 knockdown increased DNA damage and upregulated expression of the γ-H2AXS139 in the cell nucleus. Correspondingly, DNA damage was reversed after TPP1 overexpression in EC cells. Similarly, we found that the expression of ATM/ATR pathway proteins were upregulated after TPP1 knockdown, while the expression of the above proteins was downregulated after TPP1 overexpression in EC cells. TPP1 knockdown significantly inhibited the growth of transplanted tumors and upregulated the expression of ATM/ATR pathway proteins in transplanted tissues, whereas TPP1 overexpression significantly promoted their proliferation and downregulated the expression of the above proteins in vivo. Strikingly, we found that TPP1 could reduce the chemosensitivity of EC cells to cisplatin, which may have a potential link to clinical chemoresistance. In conclusion, TPP1 regulates the DNA damage response through the ATM/ATR-p53 signaling pathway and chemoresistance and may be a new target for improving the efficacy of chemotherapy in the treatment of EC.

Analysis of Hypoxia Inducible Factor-1α Expression and Its Effects on Glycolysis of Esophageal Carcinoma.

We investigated the regulatory effects of hypoxia-inducible factor-1a (HIF-1α) on glycolysis metabolism in esophageal carcinoma (ESCA) cells. A series of bioinformatics databases and tools were used to investigate the expression and role of HIF-1α in ESCA. The expression of HIF-1a in ESCA tissues and adjacent tissues was validated by real-time PCR. Small interfering RNA (siRNA) was used to inhibit HIF-1α-related genes in human ESCA cells (Eca109 and KYSE150). Cell proliferation was detected by the CCK-8 assay. The expression of HIF-1α and glycolytic enzymes were investigated by real-time PCR and Western blot. HIF-1α is highly expressed in ESCA and is involved in many biological processes such as cell hypoxia reaction, glucose metabolic process. Further in vitro experiments showed that expression of HIF-1α in Eca109 and KYSE150 significantly increased under hypoxia compared with normoxia conditions. Also, the glucose uptake and lactate production under hypoxia were higher. The expression levels of hexokinase 2 (HK2) and pyruvate dehydrogenase kinase 1 (PDK1), glycolysis-related genes, were significantly increased under hypoxia. After siRNA knockdown of HIF-1a in Eca109 and KYSE150, the glucose uptake and lactate production, as well as cell proliferation were significantly decreased under hypoxia, and HK2 and PDK1 were significantly downregulated. HIF-1α promotes glycolysis of ESCA cells by upregulating the expression of HK2 and PDK1 under hypoxia.

The M6A methyltransferase METTL3 regulates proliferation in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal human cancers with a lower 5-year survival rate. N6-methyladenosine (m6A) methylation, an important epigenetic modification, has been reported to associate with physiological and pathological processes of cancers. However, its role in ESCC remains unclear. In this work, we found that the m6A levels were elevated in ESCC cancer tissues and ESCC cells. The PPI network demonstrated that METTL3, METTL14, WTAP, RBM15, and KIAA1429 were all significantly associated with each other. Moreover, we found a significant upregulation of METTL3 mRNA and protein amounts in ESCC tissues. The METTL3 mRNA expression level of tissues had associations with ESCC differentiation extent and sex (p < 0.05). The METTL3 mRNA expression level of tissues, sensitivity for diagnosing ESCC was 75.00%, specificity was 72.06% and area under the ROC curve was 0.8030. Depletion of METTL3 markedly diminished m6A levels in human ESCC cell lines and METTL3 overexpression restored the reduction in m6A levels. These results suggested that METTL3 is the primary enzyme that modulates m6A methylation and a critical regulatory factor in ESCC. Additionally, METTL3 knockdown significantly suppressed the ESCC cell proliferation, while METTL3 overexpression markedly promoted ESCC cell proliferation both in cell and animal models. These results demonstrated that METTL3 promotes ESCC development. Furthermore, METTL3 may modulate the cell cycle of ESCC cells through a p21-dependent pattern. METTL3-guided m6A modification may contribute to the progression of ESCC via the p21-axis. Our study is the first investigation to report that METTL3-mediated m6A methylation plays a crucial role in ESCC oncogenesis and highlights that METTL3 might be a potential biomarker and therapeutic target for ESCC patients.

Identification and validation of key genes associated with non-small-cell lung cancer.

Non-small-cell lung cancer (NSCLC) is one of the main causes of death induced by cancer globally. However, the molecular aberrations in NSCLC patients remain unclearly. In the present study, four messenger RNA microarray datasets (GSE18842, GSE40275, GSE43458, and GSE102287) were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between NSCLC tissues and adjacent lung tissues were obtained from GEO2R and the overlapping DEGs were identified. Moreover, functional and pathway enrichment were performed by Funrich, while the protein-protein interaction (PPI) network construction were obtained from STRING and hub genes were visualized and identified by Cytoscape software. Furthermore, validation, overall survival (OS) and tumor staging analysis of selected hub genes were performed by GEPIA. A total of 367 DEGs (95 upregulated and 272 downregulated) were obtained through gene integration analysis. The PPI network consisted of 94 nodes and 1036 edges in the upregulated DEGs and 272 nodes and 464 edges in the downregulated DEGs, respectively. The PPI network identified 46 upregulated and 27 downregulated hub genes among the DEGs, and six (such as CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M) of that have not been identified to be associated with NSCLC so far. Moreover, the expression differences of the mentioned hub genes were consistent with that in lung adenocarcinoma and lung squamous cell carcinoma in the TCGA database. Further analysis showed that all the six hub genes were associated with tumor staging except MYH11, while only the upregulated DEG CENPE was associated with the worse OS of patients with NSCLC. In conclusion, the current study showed that CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M might be the key genes contributed to tumorigenesis or tumor progression in NSCLC, further functional study is needed to explore the involved mechanisms.

Resveratrol ameliorates gouty inflammation via upregulation of sirtuin 1 to promote autophagy in gout patients.

BACKGROUND: Resveratrol exerts an anti-inflammatory effect on collagen-induced arthritis and osteoarthritis in rats via activation of sirtuin 1 (SIRT1). Autophagy can be induced by resveratrol and leads to amelioration of interleukin-1 beta (IL-1ß) release in vitro. We aimed to determine the anti-inflammatory mechanisms of resveratrol in patients with gout. METHODS: Blood samples were obtained from patients with acute gout, intercritical gout (IG) and healthy controls (HC). The mRNA and protein levels of SIRT1 and nuclear factor-kappa B (NF-kB) p65 were determined in peripheral blood mononuclear cells (PBMCs) lysate from these patients. In the in vitro experiment, SIRT1, autophagy-related genes (beclin-1 and microtubule-associated protein 1 light-chain 3) and key genes involved in the gouty inflammatory pathway, including NF-κB p65, NLR family pyrin domain containing 3 (NLRP3), caspase-1 and IL-1ß, were determined in PBMCs lysate or plasma from IG patients exposed to monosodium urate (MSU) crystals with or without resveratrol. RESULTS: The mRNA and protein levels of SIRT1 were downregulated in PBMCs from gout patients in comparison with HC. In the in vitro experiment, the protein levels of SIRT1 were downregulated in PBMCs from IG patients exposed to MSU crystals and were restored by resveratrol in a dose-dependent manner. Furthermore, high doses of resveratrol ameliorated the release of the inflammatory cytokine IL-1ß. In addition, the mRNA levels of NLRP3 and NF-κB p65 were regulated by resveratrol, but caspase-1 and IL-1ß were not. Furthermore, resveratrol promoted MSU-induced autophagy in PBMCs from patients with gout. CONCLUSION: These findings suggest that resveratrol ameliorates gouty inflammation via upregulation of SIRT1 to promote autophagy in patients with gout.

Identification and molecular characterization of a chitin deacetylase from Bombyx mori peritrophic membrane.

The insect midgut epithelium is generally lined with a unique chitin and protein structure, the peritrophic membrane (PM), which facilitates food digestion and protects the gut epithelium. PM proteins are important determinants for PM structure and formation. In this study, the silkworm Bombyx mori midgut PM protein BmCDA7 was identified by proteomic tools. The full-length BmCDA7 cDNA is 1357 bp; the deduced protein is composed of 379 amino acid residues and includes a 16 amino acid residue signal peptide, a putative polysaccharide deacetylase-like domain and 15 cysteine residues present in three clusters. The heterologously expressed proteins of the BmCDA7 gene in yeast displayed chitin deacetylase activity. Expression of B. mori BmCDA7 was detected in the midgut at both the transcriptional and translational levels. The BmCDA7 gene was expressed by the newly hatched silkworm larvae until day seven of the fifth instar and was expressed at a high level in the newly exuviated larvae of different instars. The functions and regulatory mechanism of BmCDA7, however, need further investigation.

Antenna-specific glutathione S-transferase in male silkmoth Bombyx mori.

Glutathione S-transferases (GSTs) are multifunctional enzymes that are widely distributed in different species. GSTs detoxify exogenous and endogenous substances by conjugation to reduced glutathione. We characterized BmGSTD4, an antenna-specific GST, in male silkmoths. The full-length mRNA of Bmgstd4 was cloned by RACE-PCR and contained an open reading frame of 738 bp encoding a 245 amino acid protein. The antenna specificity of BmGSTD4 was validated at the mRNA and protein levels and BmGSTD4 was shown to localize in the sensillum of male silkmoth antennae. Homology modeling and multi-sequence alignment suggested that BmGSTD4 was a typical GST belonging to the δ class and had a canonical GST fold with a conserved N-terminus, including a glutathione-binding site and a C-terminal domain harboring a hydrophobic substrate-binding site. Restricted expression of BmGSTD4 in silkmoth antennae combined with GST activity suggested that BmGSTD4 was involved in the detoxification of harmful chemicals.

Shotgun proteomic analysis of the Bombyx mori anterior silk gland: An insight into the biosynthetic fiber spinning process.

The Bombyx mori anterior silk gland (ASG) is a natural fiber manipulator for the material provided by the middle and posterior silk glands. In view of the significant role of the ASG in the liquid-crystal spinning process, a shotgun proteomics approach was taken to study the relationship between the function of proteins in the silkworm ASG and the spinning mechanism. A total of 1132 proteins with 7647 unique peptides were identified in the ASG dataset including some involved in the cuticle, ion transportation, energy metabolism, and apoptosis. Two putative cuticle-specific proteins were highly and specifically expressed in the ASG; therefore, the ASG dataset could provide clues for comprehensive understanding of the natural silk spinning mechanism in the silkworm. All MS data have been deposited in the ProteomeXchange with identifier PXD000090.

Nucleic acid amplification with specific signal filtration and magnification for ultrasensitive colorimetric detection.

Recently, sensitive, fast and low cost nucleic acid isothermal amplification technologies (such as loop-mediated isothermal amplification, LAMP) have attracted great attention in the urgent needs of point-of-care testing (POCT) and regular epidemic prevention and control. However, unlike PCR which usually employs TaqMan probe to report specific signals, specific-signal-output strategies in isothermal amplification are immature and visual detection even rare, which limits their popularity in POCT. We hypothesize to address this issue by designing a visual-signal-report system to both filtrate and magnify the target information in isothermal amplification. In this work, we developed a specific signal filtration and magnification colorimetric isothermal sensing platform (SFMC for short) for ultrasensitive detection of DNA and RNA. SFMC consists of two processes: an isothermal amplification with specific signal filtration and a self-replication catalyzed hairpin assembly (SRCHA) for rapid target-specific signal magnification and outputting. With these unique properties, this biosensing platform could detect target DNA as low as 5 copies per reaction and target RNA as low as 10 copies per reaction by naked eyes. Benefited from the excellent colorimetric detection performance, this biosensing platform has been successfully used for African swine fever virus (ASFV) and SARS-CoV-2 detection.

Comprehensive Analysis of Potential Correlation Between Solute Carrier 1A (SLC1A) Family and Lung Adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most common dangerous malignant tumor and the leading cause of global cancer incidence and mortality. The Solute Carrier 1A (SLC1A) family play a significant part in cellular biological process, inflammation, and immunity. Specific functions of the SLC1A family in lung cancer are still not systematically described. OBJECTIVE: This study aimed to explore the best biological understanding of SLC1A family in lung cancer. METHODS: To study the expression and role of the SLC1A family in lung cancer, researchers used a variety of bioinformatics databases and tools. RESULTS: Aberrant expression of SLC1A family genes were demonstrated and analyzed the association with gender, tumor grade, cancer stages, and nodal metastasis status. The ectopic expression of SLC1A family genes has prognostic value for LUAD patients. Immune infiltration revealed a significant correlation between SLC1A family genes expression in LUAD. SLC1A family genes were involved in manifold biological processes and have different levels of DNA methylation and genetic alteration. CONCLUSIONS: These findings suggested that members of the SLC1A family could be a potential target for the development of LUAD therapeutics as well as a reliable indicator of LUAD prognostic value.

Upregulation of Yin-Yang-1 Associates with Proliferation and Glutamine Metabolism in Esophageal Carcinoma.

Objective: To investigate the expression of Yin-Yang-1 (YY1) in esophageal carcinoma (ESCA) and its effect on glutamine metabolism in ESCA. Methods: The expression and roles of YY1 in ESCA were investigated using a series of bioinformatics databases and tools. The expression of YY1 between ESCA tissues with the corresponding adjacent tissues was validated using real-time PCR, western blot, and immunohistochemical staining method. Furthermore, the effects of YY1 on ESCC cell proliferation and migration were examined. The correlation between the YY1 and glutamine metabolism was evaluated by western blot. Results: YY1 gene was highly conserved in evolution and upregulated in ESCA tissues and ESCC cell lines (ECA109 and TE-1). In addition, YY1 may affect the level of immune cell infiltration and promote tumor cell immune escape. Functional enrichment analysis found that YY1 involved in many biological processes, such as cell division and glutathione and glutamine metabolism. After siRNA knockdown of YY1 in ECA109 and TE-1, the proliferation and the migration of ECA109 and TE-1 were suppressed. The glutamine consumption and glutamate production were significantly decreased. The protein expression of alanine-, serine-, cysteine-preferring transporter 2 (ASCT2), glutaminase (GLS), and glutamate dehydrogenase (GLUD1) was significantly downregulated. Conclusion: YY1 is highly expressed in ESCA and may promote glutamine metabolism of ESCC cells, indicating it may be as a diagnostic biomarker for ESCA.

Lipoxin A4 attenuates MSU-crystal-induced NLRP3 inflammasome activation through suppressing Nrf2 thereby increasing TXNRD2.

Gout is a common inflammatory disease. The activation of NLRP3 inflammasome induced by monosodium urate (MSU) crystals has a critical role in gout, and its prevention is beneficial for patients. Lipoxin A4 (LXA4) is an endogenous lipoxygenase-derived eicosanoid mediator with powerful anti-inflammatory properties. However, whether LXA4 can suppress NLRP3 inflammasome activation induced by MSU crystals remains unclear. This study aimed to investigate the protective effect of LXA4 on MSU-crystal-induced NLRP3 inflammasome activation and its underlying molecular mechanisms. We found that LXA4 inhibited MSU-crystal-induced NLRP3 inflammasome activation, interleukin (IL)-1ß maturation, and pyroptosis. More specifically, LXA4 suppressed the assembly of the NLRP3 inflammasome, including oligomerization and speck formation of ASC, and ASC-NLRP3 interaction. Furthermore, LXA4 suppressed oxidative stress, the upstream events for NLRP3 inflammasome activation, as evidenced by the fact that LXA4 eliminated total reactive oxygen species (ROS) generation and alleviated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and mitochondrial dysfunction. However, LXA4 also depressed the Nrf2 activation, a critical molecule in the antioxidant pathway, and then exerted an inhibitory impact on Klf9 expression and promotional impact on TXNRD2 expression, two molecules located downstream of Nrf2 in sequence. Knockdown of TXNRD2 reversed the LXA4-induced depression of ROS and NLRP3 inflammasome. Moreover, LXA4 alleviated joint inflammation and decreased the production of cleaved caspase-1 and matured IL-1ß in gouty arthritis rats. Taken together, our findings demonstrate that LXA4 can attenuate MSU-crystal-induced NLRP3 inflammasome activation, probably through suppressing Nrf2 activation to increase TXNRD2 expression. The present study highlights the potential of LXA4 as an attractive new gout treatment candidate.

Investigation on the Potential Correlation Between TP53 and Esophageal Cancer.

Background: TP53 family members play an indispensable role in various human cancers, while the gene expression profiles, prognostic value, and potential mechanism in esophageal cancer (ESCA) are yet unclear. Methods: The expression and roles of TP53 family members in ESCA were investigated using the Cancer Genome Atlas (TCGA), Tumor Immune Estimation Resource (TIMER), Kaplan-Meier plotter, gene set enrichment analysis (GSEA), and UALCAN databases. The expression of TP53 between ESCA and the corresponding adjacent tissues was validated using qRT-PCR. Furthermore, the effects of TP53 on esophageal squamous cell carcinoma (ESCC) cell migration and proliferation were examined using the Transwell assay, scratch test, and crystal violet assay. The correlation between TP53 and mTOR pathways was evaluated by Western blotting. Results: This study showed a correlation between high mRNA expression of TP53 members (TP53, TP63, and TP73) and clinical cancer stages and nodal metastasis status in ESCA patients. Moreover, the expression of TP53 was significantly associated with the overall survival (OS) of ESCA patients. Additional experiments verified that the mRNA of TP53 was upregulated in ESCC patients. Moreover, the downregulated expression of TP53 significantly retarded ESCC cell migration and proliferation and might activate the mTOR signaling pathway and inhibit TP53-dependent autophagy. Conclusion: TP53 has a prognostic value in ESCA and may be a leading factor in promoting ESCA pathogenesis.

Identification of miRNAs and genes for predicting Barrett's esophagus progressing to esophageal adenocarcinoma using miRNA-mRNA integrated analysis.

Barrett's esophagus (BE) is defined as any metaplastic columnar epithelium in the distal esophagus, which predisposes to esophageal adenocarcinoma (EAC). Yet, the mechanism through which BE develops to EAC still remain unclear. Moreover, the miRNA-mRNA regulatory network in distinguishing BE from EAC still remains poorly understood. To identify differentially expressed miRNAs (DEMs) and genes (DEGs) between EAC and BE from tissue samples, gene expression microarray datasets GSE13898, GSE26886, GSE1420 and miRNA microarray datasets GSE16456, GSE20099 were downloaded from Gene Expression Omnibus (GEO) database. GEO2R was used to screen the DEMs and DEGs. Pathway and functional enrichment analysis were performed by DAVID database. The protein-protein interaction (PPI) network was constructed by STRING and been visualized by Cytoscape software. Finnal, survival analysis was performed basing TCGA database. A total of 21 DEMs were identified. The enriched functions and pathways analysis inclued Epstein-Barr virus infection, herpesvirus infection and TRP channels. GART, TNFSF11, GTSE1, NEK2, ICAM1, PSMD12, CTNNB1, CDH1, PSEN1, IL1B, CTNND1, JAG1, CDH17, ITCH, CALM1 and ITGA6 were considered as the hub-genes. Hsa-miR-143 and hsa-miR-133b were the highest connectivity target gene. JAG1 was predicted as the largest number of target miRNAs. The expression of hsa-miR-181d, hsa-miR-185, hsa-miR-15b, hsa-miR-214 and hsa-miR-496 was significantly different between normal tissue and EAC. CDH1, GART, GTSE1, NEK2 and hsa-miR-496, hsa-miR-214, hsa-miR-15b were found to be correlated with survival.

Dihydroartemisinin as a Sensitizing Agent in Cancer Therapies.

Cancer is one of the major threats to human health. Although humans have struggled with cancer for decades, the efficacy of treatments for most tumors is still very limited. Dihydroartemisinin (DHA) is a derivative of artemisinin, a first-line antimalarial drug originally developed in China. Beyond the anti-malarial effect, DHA has also been reported to show anti-inflammatory, anti-parasitosis, and immune-modulating properties in vitro and in vivo. Furthermore, an increasing number of studies report that DHA possesses anticancer activities on a wide range of cancer types both in vitro and in vivo, as well as enhances the efficacy of chemotherapy, targeted therapy, and even radiotherapy. However, the mechanisms of DHA on different tumors differ in various ways. In this review, we intend to summarize how DHA sensitizes cancer cells to anti-cancer therapies, highlight its molecular mechanisms and pharmacological effects in vitro and in vivo as well as in current clinical trials, and discuss potential issues concerning DHA. Hopefully, more attention will be paid to DHA as a sensitizer for cancer therapy in the future.

MicroRNA-449a inhibits cell proliferation and migration by regulating mutant p53 in MDA-MB-468 cells.

The present study aimed to investigate the role of microRNA (miR)-449a in the proliferation, migration and apoptosis of MDA-MB-468 breast cancer cells and examine the association between miR-449a and mutant p53 in these cells. Cell proliferation, migration and invasion were examined using a crystal violet staining assay, wound healing scratch assay and Transwell assay, respectively. The expression level of miR-449a and p53 was detected by reverse transcription-quantitative PCR or western blotting. The results indicated that knockdown of mutant p53 suppressed the proliferation and migration of MDA-MB-468 cells by inhibiting the PI3K/AKT/mTOR signaling pathway. In addition, miR-449a suppressed proliferation and migration via downregulation of mutant p53 expression in MDA-MB-468 cells. Therefore, miR-449a may function as a tumor suppressor by regulating p53 expression in breast cancer cells, which may have potential implications in the treatment of patients with triple-negative breast cancer carrying mutant p53.

Human Telomerase Reverse Transcriptase as a Therapeutic Target of Dihydroartemisinin for Esophageal Squamous Cancer.

Objective: To elucidate the oncogenic role of human telomerase reverse transcriptase (hTERT) in esophageal squamous cancer and unravel the therapeutic role and molecular mechanism of dihydroartemisinin (DHA) by targeting hTERT. Methods: The expression of hTERT in esophageal squamous cancer and the patients prognosis were analyzed by bioinformatic analysis from TCGA database, and further validated with esophageal squamous cancer tissues in our cohort. The Cell Counting Kit-8 (CCK8) and colony formation assay were used to evaluate the proliferation of esophageal squamous cancer cell lines (Eca109, KYSE150, and TE1) after hTERT overexpression or treated with indicated concentrations of DHA. Transwell migration assay and scratch assay were employed to determine the migration abilities of cancer cells. Fluorescence microscopy and flow cytometry were conducted to measure the intracellular reactive oxygen species (ROS) levels in cancer cells after treated with DHA. Moreover, RT-PCR and Western blot were performed to test the alteration of associated genes on mRNA and protein level in DHA treated esophageal squamous cancer cell lines, respectively. Furthermore, tumor-bearing nude mice were employed to evaluate the anticancer effect of DHA in vivo. Results: We found that hTERT was significantly upregulated in esophageal squamous cancer both from TCGA database and our cohort also. Overexpression of hTERT evidently promoted the proliferation and migration of esophageal squamous cancer cells in vitro. Moreover, DHA could significantly inhibit the proliferation and migration of esophageal cancer cell lines Eca109, KYSE150, and TE1 in vitro, and significantly down-regulate the expression of hTERT on both mRNA and protein level in a time- and dose-dependent manner as well. Further studies showed that DHA could induce intracellular ROS production in esophageal cancer cells and down-regulate SP1 expression, a transcription factor that bound to the promoter region of hTERT gene. Moreover, overexpression of SP1 evidently promoted the proliferation and migration of Eca109 and TE1 cells. Intriguingly, rescue experiments showed that inhibiting ROS by NAC alleviated the downregulation of SP1 and hTERT in cells treated with DHA. Furthermore, overexpression of SP1 or hTERT could attenuate the inhibition effect of DHA on the proliferation and migration of Eca109 cells. In tumor-bearing nude mice model, DHA significantly inhibited the growth of esophageal squamous cancer xenografts, and downregulated the expression of SP1 and hTERT protein, while no side effects were observed from heart, kidney, liver, and lung tissues by HE stain. Conclusion: hTERT plays an oncogenic role in esophageal squamous cancer and might be a therapeutic target of DHA through regulating ROS/SP1 pathway.