TGFß signaling links early life endocrine-disrupting chemicals exposure to suppression of nucleotide excision repair in rat myometrial stem cells.

Environmental exposure to endocrine-disrupting chemicals (EDCs) is linked to the development of uterine fibroids (UFs) in women. UFs, non-cancerous tumors, are thought to originate from abnormal myometrial stem cells (MMSCs). Defective DNA repair capacity may contribute to the emergence of mutations that promote tumor growth. The multifunctional cytokine TGFß1 is associated with UF progression and DNA damage repair pathways. To investigate the impact of EDC exposure on TGFß1 and nucleotide excision repair (NER) pathways, we isolated MMSCs from 5-month-old Eker rats exposed neonatally to diethylstilbestrol (DES), an EDC, or to vehicle (VEH). EDC-MMSCs exhibited overactivated TGFß1 signaling and reduced mRNA and protein levels of NER pathway components compared to VEH-MMSCs. EDC-MMSCs also demonstrated impaired NER capacity. Exposing VEH-MMSCs to TGFß1 decreased NER capacity while inhibiting TGFß signaling in EDC-MMSCs restored it. RNA-seq analysis and further validation revealed decreased expression of Uvrag, a tumor suppressor gene involved in DNA damage recognition, in VEH-MMSCs treated with TGFß1, but increased expression in EDC-MMSCs after TGFß signaling inhibition. Overall, we demonstrated that the overactivation of the TGFß pathway links early life exposure to EDCs with impaired NER capacity, which would lead to increased genetic instability, arise of mutations, and fibroid tumorigenesis. We demonstrated that the overactivation of the TGFß pathway links early life exposure to EDCs with impaired NER capacity, which would lead to increased fibroid incidence.

NAT10 regulates the repair of UVB-induced DNA damage and tumorigenicity.

Chemical modifications in messenger RNA (mRNA) regulate gene expression and play critical roles in stress responses and diseases. Recently we have shown that N6-methyladenosine (m6A), the most abundant mRNA modification, promotes the repair of UVB-induced DNA damage by regulating global genome nucleotide excision repair (GG-NER). However, the roles of other mRNA modifications in the UVB-induced damage response remain understudied. N4-acetylcytidine (ac4C) is deposited in mRNA by the RNA-binding acetyltransferase NAT10. This NAT10-mediated ac4C in mRNA has been reported to increase both mRNA stability and translation. However, the role of ac4C and NAT10 in the UVB-induced DNA damage response remains poorly understood. Here we show that NAT10 plays a critical role in the repair of UVB-induced DNA damage lesions through regulating the expression of the key GG-NER gene DDB2. We found that knockdown of NAT10 enhanced the repair of UVB-induced DNA damage lesions by promoting the mRNA stability of DDB2. Our findings are in contrast to the previously reported role of NAT10-mediated ac4C deposition in promoting mRNA stability and may represent a novel mechanism for ac4C in the UVB damage response. Furthermore, NAT10 knockdown in skin cancer cells decreased skin cancer cell proliferation in vitro and tumorigenicity in vivo. Chronic UVB irradiation increases NAT10 protein levels in mouse skin. Taken together, our findings demonstrate a novel role for NAT10 in the repair of UVB-induced DNA damage products by decreasing the mRNA stability of DDB2 and suggest that NAT10 is a potential novel target for preventing and treating skin cancer.

TGFß signaling links early-life endocrine-disrupting chemicals exposure to suppression of nucleotide excision repair in rat myometrial stem cells.

Environmental exposure to endocrine-disrupting chemicals (EDCs) is linked to the development of uterine fibroids (UFs) in women. UFs, non-cancerous tumors, are thought to originate from abnormal myometrial stem cells (MMSCs). Defective DNA repair capacity may contribute to the emergence of mutations that promote tumor growth. The multifunctional cytokine TGFß1 is associated with UF progression and DNA damage repair pathways. To investigate the impact of EDC exposure on TGFß1 and nucleotide excision repair (NER) pathways, we isolated MMSCs from 5-months old Eker rats exposed neonatally to Diethylstilbestrol (DES), an EDC, or to vehicle (VEH). EDC-MMSCs exhibited overactivated TGFß1 signaling and reduced mRNA and protein levels of NER pathway components compared to VEH-MMSCs. EDC-MMSCs also demonstrated impaired NER capacity. Exposing VEH-MMSCs to TGFß1 decreased NER capacity while inhibiting TGFß signaling in EDC-MMSCs restored it. RNA-seq analysis and further validation revealed decreased expression of Uvrag, a tumor suppressor gene involved in DNA damage recognition, in VEH-MMSCs treated with TGFß1, but increased expression in EDC-MMSCs after TGFß signaling inhibition. Overall, we demonstrated that the overactivation of the TGFß pathway links early-life exposure to EDCs with impaired NER capacity, which would lead to increased genetic instability, arise of mutations, and fibroid tumorigenesis. We demonstrated that the overactivation of the TGFß pathway links early-life exposure to EDCs with impaired NER capacity, which would lead to increased fibroid incidence.

Human Neuralized is a novel tumour suppressor targeting Wnt/ß-catenin signalling in colon cancer.

While there is growing evidence that many epigenetically silenced genes in cancer are tumour suppressor candidates, their significance in cancer biology remains unclear. Here, we identify human Neuralized (NEURL), which acts as a novel tumour suppressor targeting oncogenic Wnt/ß-catenin signalling in human cancers. The expression of NEURL is epigenetically regulated and markedly suppressed in human colorectal cancer. We, therefore, considered NEURL to be a bona fide tumour suppressor in colorectal cancer and demonstrate that this tumour suppressive function depends on NEURL-mediated oncogenic ß-catenin degradation. We find that NEURL acts as an E3 ubiquitin ligase, interacting directly with oncogenic ß-catenin, and reducing its cytoplasmic levels in a GSK3ß- and ß-TrCP-independent manner, indicating that NEURL-ß-catenin interactions can lead to a disruption of the canonical Wnt/ß-catenin pathway. This study suggests that NEURL is a therapeutic target against human cancers and that it acts by regulating oncogenic Wnt/ß-catenin signalling.

Protective effects of leonurine hydrochloride on pyroptosis in premature ovarian insufficiency via regulating NLRP3/GSDMD pathway.

BACKGROUND: Premature ovarian insufficiency is common in clinically infertile patients. The NOD-like receptor family pyrin domain-containing 3 (NLRP3)/Gasdermin D (GSDMD) signaling pathway plays a key role in premature ovarian insufficiency. Leonurine (Leo) is one of the important active ingredients extracted from Leonurus japonicus Houttuyn, which can inhibit NLRP3 activation. However, whether leonurine hydrochloride plays a protective role in premature ovarian insufficiency through actions on NLRP3/GSDMD signaling is not yet known. METHODS: After cyclophosphamide-induced premature ovarian insufficiency was established in female mice, Leo was injected intraperitoneally over four weeks to evaluate the ovarian function and anti-pyroptosis effects using the metrics of fertility, serum hormone level, ovary weight, follicle number, expression of NLRP3/GSDMD pathway-related proteins, and serum IL-18 and IL-1ß levels. RESULTS: Intraperitoneal administration of leonurine hydrochloride was found to significantly protect fertility and maintain both serum hormone levels and follicle number in mice with premature ovarian insufficiency. Mice treated with leonurine hydrochloride consistently resisted cyclophosphamide-induced ovarian damage by inhibiting the activation of NLRP3 inflammasome, Caspase-1 and GSDMD in both ovarian tissue and granulosa cells, which led to lower levels of IL-18 and IL-1ß in the serum (p < 0.05, p < 0.01, p < 0.001). CONCLUSION: Intraperitoneal administration of leonurine hydrochloride prevents cyclophosphamide-induced premature ovarian insufficiency in mice by inhibiting NLRP3/GSDMD-mediated pyroptosis.

Moderate Low UVB Irradiation Modulates Tumor-associated Macrophages and Dendritic Cells and Promotes Antitumor Immunity in Tumor-bearing Mice.

Excessive, high doses of ultraviolet B (UVB) UVB irradiation are known to cause skin cancer, aging and immunosuppression. On the contrary, moderate low doses of UVB irradiation are shown to be essential and beneficial to human health, including a tumor-suppressive effect. However, the mechanism by which low levels of UVB suppress tumorigenesis remains unclear. Here, using tumor-bearing mouse models, we show that moderate low repetitive UVB irradiation increases the percentage of activated CD4+ and CD8+ T cells, and CD103+ conventional type 1 dendritic cells (cDC1s), while it decreases the number of immunosuppressive, M2-like macrophages in the tumors. Finally, in mice, deletion of Batf3, a transcription factor critical for the development of conventional dendritic cells, including the CD103+ cDC1s, showed increased tumor growth in both sham- and UVB-irradiated mice. Our findings demonstrate that moderate low UVB irradiation inhibits M2-like tumor-associated macrophages, increases CD103+ cDC1s and promotes antitumor immunity in mice with an established tumor.

Efficient exploration of complex free energy landscapes by stepwise multi-subphase space metadynamics.

We present an efficient method based on an extension of metadynamics for exploring complex free energy landscapes (FELs). The method employs two-step metadynamics simulations. In the first step, rapid metadynamics simulations using broad and tall Gaussians are performed to identify a free energy pathway (FEP) connecting the two states of interest. The FEP is then divided into a series of independent subphase spaces that comprise selected discrete images of the system. Using appropriate collective variables (CVs) chosen according to the FEP, the accurate FEL of each subphase space is separately calculated in subsequent divide-and-conquer metadynamics simulations with narrow and low Gaussians. Finally, all FELs calculated in each subphase space are merged to obtain the full FEL. We show that the method greatly improves the performance of the metadynamics approach. In particular, we are able to efficiently model chemical systems with complex FELs, such as chemical reactions at the air/water interface. We demonstrate the performance of this method on two model reactions: the hydrolysis of formaldehyde in the gas phase and at the air/water interface.

Development of protective agents against ovarian injury caused by chemotherapeutic drugs.

BACKGROUND: Chemotherapy is one of the causes of ovarian injury and infertility. Although assisted reproductive technology helps young female patients with cancer become pregnant, preventing chemotherapy-induced ovarian injury will often possess even more significant benefits. OBJECTIVE: We aimed at demonstrating the hazardous effects and mechanisms of ovarian injury by chemotherapeutic agents, as well as demonstrating agents that protect the ovary from chemotherapy-induced injury. RESULTS: Chemotherapeutic agents cause death or accelerate activation of follicles and damage to the blood vessels in the ovary, resulting in inflammation. These often require drug development to protect the ovaries from injury. CONCLUSIONS: Our findings provide a basis for the development of drugs to protect the ovaries from injury. Although there are many preclinical studies on potential protective drugs, there is still an urgent need for a large number of clinical experiments to verify their potential use.

Roles of RNA Modifications in Diverse Cellular Functions.

Chemical modifications of RNA molecules regulate both RNA metabolism and fate. The deposition and function of these modifications are mediated by the actions of writer, reader, and eraser proteins. At the cellular level, RNA modifications regulate several cellular processes including cell death, proliferation, senescence, differentiation, migration, metabolism, autophagy, the DNA damage response, and liquid-liquid phase separation. Emerging evidence demonstrates that RNA modifications play active roles in the physiology and etiology of multiple diseases due to their pervasive roles in cellular functions. Here, we will summarize recent advances in the regulatory and functional role of RNA modifications in these cellular functions, emphasizing the context-specific roles of RNA modifications in mammalian systems. As m6A is the best studied RNA modification in biological processes, this review will summarize the emerging advances on the diverse roles of m6A in cellular functions. In addition, we will also provide an overview for the cellular functions of other RNA modifications, including m5C and m1A. Furthermore, we will also discuss the roles of RNA modifications within the context of disease etiologies and highlight recent advances in the development of therapeutics that target RNA modifications. Elucidating these context-specific functions will increase our understanding of how these modifications become dysregulated during disease pathogenesis and may provide new opportunities for improving disease prevention and therapy by targeting these pathways.

ALKBH4 Stabilization Is Required for Arsenic-Induced 6mA DNA Methylation Inhibition, Keratinocyte Malignant Transformation, and Tumorigenicity.

Inorganic arsenic is one of the well-known human skin carcinogens. However, the molecular mechanism by which arsenic promotes carcinogenesis remains unclear. Previous studies have established that epigenetic changes, including changes in DNA methylation, are among the critical mechanisms that drive carcinogenesis. N6-methyladenine (6mA) methylation on DNA is a widespread epigenetic modification that was initially found on bacterial and phage DNA. Only recently has 6mA been identified in mammalian genomes. However, the function of 6mA in gene expression and cancer development is not well understood. Here, we show that chronic low doses of arsenic induce malignant transformation and tumorigenesis in keratinocytes and lead to the upregulation of ALKBH4 and downregulation of 6mA on DNA. We found that reduced 6mA levels in response to low levels of arsenic were mediated by the upregulation of the 6mA DNA demethylase ALKBH4. Moreover, we found that arsenic increased ALKBH4 protein levels and that ALKBH4 deletion impaired arsenic-induced tumorigenicity in vitro and in mice. Mechanistically, we found that arsenic promoted ALKBH4 protein stability through reduced autophagy. Together, our findings reveal that the DNA 6mA demethylaseALKBH4 promotes arsenic tumorigenicity and establishes ALKBH4 as a promising target for arsenic-induced tumorigenesis.

METTL14 facilitates global genome repair and suppresses skin tumorigenesis.

Global genome repair (GGR), a subpathway of nucleotide excision repair, corrects bulky helix-distorting DNA lesions across the whole genome and is essential for preventing mutagenesis and skin cancer. Here, we show that METTL14 (methyltransferase-like 14), a critical component of the N6-methyladenosine (m6A) RNA methyltransferase complex, promotes GGR through regulating m6A mRNA methylation-mediated DDB2 translation and suppresses ultraviolet B (UVB) radiation-induced skin tumorigenesis. UVB irradiation down-regulates METTL14 protein through NBR1-dependent selective autophagy. METTL14 knockdown decreases GGR and DDB2 abundance. Conversely, overexpression of wild-type METTL14 but not its enzymatically inactive mutant increases GGR and DDB2 abundance. METTL14 knockdown decreases m6A methylation and translation of the DDB2 transcripts. Adding DDB2 reverses the GGR repair defect in METTL14 knockdown cells, indicating that METTL14 facilitates GGR through regulating DDB2 m6A methylation and translation. Similarly, knockdown of YTHDF1, an m6A reader promoting translation of m6A-modified transcripts, decreases DDB2 protein levels. Both METTL14 and YTHDF1 bind to the DDB2 transcript. In mice, skin-specific heterozygous METTL14 deletion increases UVB-induced skin tumorigenesis. Furthermore, METTL14 as well as DDB2 is down-regulated in human and mouse skin tumors and by chronic UVB irradiation in mouse skin, and METTL14 level is associated with the DDB2 level, suggesting a tumor-suppressive role of METTL14 in UVB-associated skin tumorigenesis in association with DDB2 regulation. Taken together, these findings demonstrate that METTL14 is a target for selective autophagy and acts as a critical epitranscriptomic mechanism to regulate GGR and suppress UVB-induced skin tumorigenesis.

Autophagy of the m6A mRNA demethylase FTO is impaired by low-level arsenic exposure to promote tumorigenesis.

Here we show that FTO as an N6-methyladenosine (m6A) RNA demethylase is degraded by selective autophagy, which is impaired by low-level arsenic exposure to promote tumorigenesis. We found that in arsenic-associated human skin lesions, FTO is upregulated, while m6A RNA methylation is downregulated. In keratinocytes, chronic relevant low-level arsenic exposure upregulated FTO, downregulated m6A RNA methylation, and induced malignant transformation and tumorigenesis. FTO deletion inhibited arsenic-induced tumorigenesis. Moreover, in mice, epidermis-specific FTO deletion prevented skin tumorigenesis induced by arsenic and UVB irradiation. Targeting FTO genetically or pharmacologically inhibits the tumorigenicity of arsenic-transformed tumor cells. We identified NEDD4L as the m6A-modified gene target of FTO. Finally, arsenic stabilizes FTO protein through inhibiting p62-mediated selective autophagy. FTO upregulation can in turn inhibit autophagy, leading to a positive feedback loop to maintain FTO accumulation. Our study reveals FTO-mediated dysregulation of mRNA m6A methylation as an epitranscriptomic mechanism to promote arsenic tumorigenicity.

Context-Dependent Roles of RNA Modifications in Stress Responses and Diseases.

RNA modifications are diverse post-transcriptional modifications that regulate RNA metabolism and gene expression. RNA modifications, and the writers, erasers, and readers that catalyze these modifications, serve as important signaling machineries in cellular stress responses and disease pathogenesis. In response to stress, RNA modifications are mobilized to activate or inhibit the signaling pathways that combat stresses, including oxidative stress, hypoxia, therapeutic stress, metabolic stress, heat shock, DNA damage, and ER stress. The role of RNA modifications in response to these cellular stressors is context- and cell-type-dependent. Due to their pervasive roles in cell biology, RNA modifications have been implicated in the pathogenesis of different diseases, including cancer, neurologic and developmental disorders and diseases, and metabolic diseases. In this review, we aim to summarize the roles of RNA modifications in molecular and cellular stress responses and diseases.

Keratinocyte autophagy enables the activation of keratinocytes and fibroblastsand facilitates wound healing.

Macroautophagy/autophagy is a cellular catabolic process that is implicated in several physiological and pathological processes. However, the role of epidermal autophagy in wound healing remains unknown. Here, using mice with genetic ablation of the essential Atg5 (autophagy related 5) or Atg7 (autophagy related 7) in their epidermis to inhibit autophagy, we show that keratinocyte autophagy regulates wound healing in mice. Wounding induces the expression of autophagy genes in mouse skin. Epidermis-specific autophagy deficiency inhibits wound closure, re-epithelialization, keratinocyte proliferation and differentiation, dermal granulation tissue formation, and infiltration of immune cells including macrophages, neutrophils, and mast cells, while it does not affect angiogenesis. Using cytokine array screening, we found that autophagy deficiency inhibits the transcription and production of the cytokine CCL2/MCP-1 by TNF. At the molecular level, TNF induces autophagic flux and the expression of autophagy genes through NFKB in epidermal keratinocytes. TNF promotes CCL2 transcription through the autophagy-AMPK-BRAF-MAPK1/3/ERK-activator protein 1 (AP1) pathway. Indeed, treating mice with recombinant CCL2 can reverse the effect of autophagy deficiency in keratinocytes. At the cellular level, we found that CCL2 induction via autophagy in keratinocytes is required not only for keratinocyte migration and proliferation but also for dermal fibroblast activation. Our findings demonstrate a critical role of epidermal autophagy in wound healing in vivo and elucidate a critical molecular machinery coordinating keratinocyte-fibroblast interaction in skin repair.Abbreviations: ACTA2/α-SMA: actin alpha 2, smooth muscle; ACTB: ß-actin; ADGRE1: adhesion G protein-coupled receptor E1; AMPK: AMP-activated protein kinase; AP1: activator protein 1; AP1-RE: AP1 response element; ATG: autophagy-related; ATG16L1: autophagy related 16 like 1; BECN1: beclin 1; BRAF: B-Raf proto-oncogene, serine/threonine kinase; C5: complement C5; CCL2/MCP-1: C-C motif chemokine ligand 2; CCL3: C-C motif chemokine ligand 3; CK: cytokeratin; cKO: conditional knockout; CRTC1: CREB-regulated transcription coactivator 1; CXCL1: C-X-C motif chemokine ligand 1; CXCL2: C-X-C motif chemokine ligand 2; ECM: extracellular matrix; EGF: epidermal growth factor; FGF7: fibroblast growth factor 7; GABARAPL2: GABA type A receptor associated protein like 2; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HBEGF: heparin binding EGF like growth factor; HPRT1: hypoxanthine phosphoribosyltransferase 1; IHC: immunohistochemical; IL1B: interleukin 1 beta; KRT10: keratin 10; KRT14: keratin 14; MAP1LC3B/LC3B-I/II: microtubule-associated protein 1 light chain 3 beta; MAPK1/3/ERK: mitogen-activated protein kinase 1/3; MKI67/Ki-67: marker of proliferation; MPO: myeloperoxidase; NFKB: NF-kappa B, nuclear factor kappa-light-chain-enhancer of activated B cells; NFKB-RE: NFKB response element; PDGF: platelet-derived growth factor; PECAM1: platelet and endothelial cell adhesion molecule 1; PRKAA1: protein kinase AMP-activated catalytic subunit alpha 1; RELA/p65: RELA proto-oncogene, NFKB subunit; shCON: small hairpin negative control; siNC: negative control; siRNA: small interfering RNA; SP1: sp1 transcription factor; SQSTM1/p62: sequestosome 1; TGFA: transforming growth factor alpha; TGFB1: transforming growth factor beta 1; TIMP1: TIMP metallopeptidase inhibitor 1; TNF/TNF-alpha: tumor necrosis factor; TREM1: triggering receptor expressed on myeloid cells 1; WT: wild-type.

Design and photoelectric properties of D-A-π-A carbazole dyes with different π-spacers and acceptors for use in solar cells: a DFT and TD-DFT investigation.

Density functional theory (DFT) and time-dependent DFT (TD-DFT) were used to calculate the properties of the carbazole dyes TYZ-1 to TYZ-5, which differed in their π-spacers. The carbazole dyes TYZ-6 and TYZ-7 were then designed; these were based on TYZ-3 (which had 2,2':5',2″-terthiophene as its π-spacer) but had more strongly electron-withdrawing second acceptor groups than TYZ-3. All of these dyes except for TYZ-5 presented quasi-planar conformations, and the calculated energies of their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) molecular orbitals as well as their HOMO-LUMO gaps (Eg) suggest that these dyes are suitable for use as sensitizers. Lengthening the π-spacer and increasing its degree of conjugation were found to cause the absorption spectrum of the dye to redshift and to facilitate hole injection. The Eg values of TYZ-6 and TYZ-7 were calculated to be smaller than that of TYZ-3 due to the weaker electron-withdrawing power of the second acceptor group in TYZ-3, and the dyes TYZ-2, TYZ-3, TYZ-6, and TYZ-7 presented the smallest Eg values. Local electron excitations following UV-vis absorption led to electronic transitions, particularly HOMO to LUMO transitions (> 94.3% of all transitions). The excited states of these dyes were found to have quasi-planar conformations, although their dihedral angles were smaller than those in the corresponding ground states. The Stokes Shifts calculated for the seven dyes (which ranged from 51.9 to 98.1 nm) suggested that self-absorption was unlikely to occur. Overall, the calculations indicated that the dyes TYZ-2, TYZ-3, TYZ-6, and TYZ-7 are promising candidates for use in dye-sensitized solar cells.

m6A mRNA demethylase FTO regulates melanoma tumorigenicity and response to anti-PD-1 blockade.

Melanoma is one of the most deadly and therapy-resistant cancers. Here we show that N6-methyladenosine (m6A) mRNA demethylation by fat mass and obesity-associated protein (FTO) increases melanoma growth and decreases response to anti-PD-1 blockade immunotherapy. FTO level is increased in human melanoma and enhances melanoma tumorigenesis in mice. FTO is induced by metabolic starvation stress through the autophagy and NF-κB pathway. Knockdown of FTO increases m6A methylation in the critical protumorigenic melanoma cell-intrinsic genes including PD-1 (PDCD1), CXCR4, and SOX10, leading to increased RNA decay through the m6A reader YTHDF2. Knockdown of FTO sensitizes melanoma cells to interferon gamma (IFNγ) and sensitizes melanoma to anti-PD-1 treatment in mice, depending on adaptive immunity. Our findings demonstrate a crucial role of FTO as an m6A demethylase in promoting melanoma tumorigenesis and anti-PD-1 resistance, and suggest that the combination of FTO inhibition with anti-PD-1 blockade may reduce the resistance to immunotherapy in melanoma.

The Role of Dynamic m6 A RNA Methylation in Photobiology.

N6 -methyladenosine (m6 A) is the most abundant internal RNA modification among numerous post-transcriptional modifications identified in eukaryotic mRNA. m6 A modification of RNA is catalyzed by the "writer" m6 A methyltransferase enzyme complex, consisting of METTL3, METTL14, WTAP and KIAA1429. The m6 A modification is reversible and can be removed by "eraser" m6 A demethylase enzymes, namely, FTO and ALKBH5. The biological function of m6 A modification on RNA is carried out by RNA-binding effector proteins called "readers." Varied functions of the reader proteins regulate mRNA metabolism by affecting stability, translation, splicing or nuclear export. The epitranscriptomic gene regulation by m6 A RNA methylation regulates various pathways, which contribute to basic cellular processes essential for cell maintenance, development and cell fate, and affect response to external stimuli and stressors. In this review, we summarize the recent advances in the regulation and function of m6 A RNA methylation, with a focus on UV-induced DNA damage response and the circadian clock machinery. Insights into the mechanisms of m6 A RNA regulation and post-transcriptional regulatory function in these biological processes may facilitate the development of new preventive and therapeutic strategies for various diseases related to dysregulation of UV damage response and circadian rhythm.

[Correlation between the genotypes and clinical symptoms of human papilloma virus in male outpatients at STD clinics].

OBJECTIVE: To investigate the distribution of the human papilloma virus (HPV) and its genotypes in the male outpatients at the clinics of sexually transmitted diseases (STD) in Changshu and analyze its association with the primary clinical symptoms so as to provide some evidence for the prevention and treatment of HPV infection in men. METHODS: We collected exfoliated cell samples from the external genitals of 602 male outpatients at the STD clinics in Changshu from February 2016 to February 2018, extracted and amplified nucleic acids from the samples, and detected the HPV genotypes using the gene chip technique. We performed statistical analyses on the types of symptoms in clinical diagnosis and their correlation with the genotypes of HPV using the chi-square test. RESULTS: The HPV positive rate in the male STD clinics was 48.2%, of which 47.2 % fell into the low-risk type, 30.0% with multiple infections. The main genotypes included HPV types 6, 11, 39, and 52, and the main HPV-related clinical symptoms were verruca (43.1%) and erythra (41.0%). Low-risk types 6 and 11 accounted for a significantly higher percentage than the high-risk types in the verruca patients (60.0% vs 15.0%, , P < 0.05), but showed no statistically significant difference from the latter in the erythra patients (38.7% vs 38.7%, P > 0.05). The incidence of low-risk infection was remarkably higher than that of high-risk infection in the acrobystitis and balanitis patients (P < 0.05), while the high-risk types constituted a markedly higher percentage than the low-risk and high- and low-risk mixed types in the asymptomatic men at physical examination (84.6% vs 0.0% and 15.4%, P < 0.05). CONCLUSIONS: The HPV positive rate was as high as 48.2% in the males at the STD clinics in Changshu, and the main infection type was low-risk genotype single infection. The clinical symptoms of low-risk infection were mainly verruca and prepuce balanitis, and the high-risk type was mostly asymptomatic at physical examination.