Bioactivities and chemical profiling comparison and metabolomic variations of polyphenolics and steroidal glycoalkaloids in different parts of Solanum nigrum L.

INTRODUCTION: Solanum nigrum L. is a traditional medicinal herb and edible plant. Many studies provide evidence that S. nigrum L. is a nutritious vegetable. Polyphenols and steroidal glycoalkaloids are the main components. OBJECTIVES: This study aimed to systemically evaluate the phytochemical profile, quantification, and bioactivities of polyphenolics and glycoalkaloids in different parts of S. nigrum L. RESULTS: Total polyphenols (TPC) and total glycoalkaloids (TGK) were determined using the Folin-Ciocalteu and acid dye colorimetric methods, respectively. A total of 55 polyphenolic constituents (including 22 phenolic acids and 33 flavonoids) and 24 steroidal glycoalkaloids were identified from different parts using ultrahigh-performance liquid chromatography Q-exactive high-resolution mass spectrometry (UHPLC-QE-HRMS), of which 40 polyphenols (including 15 phenolic acids and 25 flavonoids) and one steroidal glycoalkaloid were characterised for the first time in S. nigrum L. Moreover, typical polyphenols and glycoalkaloids were determined using HPLC-UV and HPLC-evaporative light-scattering detector (ELSD), respectively. In addition, the TPC and TGK and their typical constituents were compared in different anatomical parts. Finally, the antioxidant capacities of polyphenolic extracts from different parts of S. nigrum L. were evaluated by ·OH, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric-reducing antioxidant power (FRAP) assay in vitro. In addition, the antitumour effects of TGK from different parts of S. nigrum L. on the proliferation of PC-3 cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Polyphenolic and glycoalkaloid extracts from different parts of S. nigrum L. showed different antioxidant and cytotoxic capacities in vitro. CONCLUSION: This is the first study to systematically differentiate between polyphenolic and glycoalkaloid profiles from different parts of S. nigrum L.

FOXK1 regulates malignant progression and radiosensitivity through direct transcriptional activation of CDC25A and CDK4 in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a serious malignancy with poor prognosis, necessitating identification of oncogenic mechanisms for novel therapeutic strategies. Recent studies have highlighted the significance of the transcription factor forkhead box K1 (FOXK1) in diverse biological processes and carcinogenesis of multiple malignancies, including ESCC. However, the molecular pathways underlying FOXK1's role in ESCC progression are not fully understood, and its potential role in radiosensitivity remains unclear. Here, we aimed to elucidate the function of FOXK1 in ESCC and explore the underlying mechanisms. Elevated FOXK1 expression levels were found in ESCC cells and tissues, positively correlated with TNM stage, invasion depth, and lymph node metastasis. FOXK1 markedly enhanced the proliferative, migratory and invasive capacities of ESCC cells. Furthermore, silencing FOXK1 resulted in heightened radiosensitivity by impeding DNA damage repair, inducing G1 arrest, and promoting apoptosis. Subsequent studies demonstrated that FOXK1 directly bound to the promoter regions of CDC25A and CDK4, thereby activating their transcription in ESCC cells. Moreover, the biological effects mediated by FOXK1 overexpression could be reversed by knockdown of either CDC25A or CDK4. Collectively, FOXK1, along with its downstream target genes CDC25A and CDK4, may serve as a promising set of therapeutic and radiosensitizing targets for ESCC.

Reciprocal regulation of LINC00941 and SOX2 promotes progression of esophageal squamous cell carcinoma.

LINC00941 is a novel long noncoding RNA (lncRNA) and emerging as an important factor in cancer development. However, the exact function and relative regulatory mechanism of LINC00941 in carcinogenesis of esophageal squamous cell carcinoma (ESCC) remain to be further clarified. The present study was to investigate the expression level, functions, and mechanisms of LINC00941 in ESCC tumorigenesis. LINC00941 was significantly upregulated in ESCC, and upregulated LINC00941 was correlated with dismal patient outcomes. LINC00941 functioned as an oncogene by promoting cells proliferation, stemness, migration, and invasion in ESCC. In terms of mechanisms, SOX2 could bind directly to the promoter region of LINC00941 and activate its transcription. In turn, LINC00941 upregulated SOX2 through interacting with interleukin enhancer binding factor 2 (ILF2) and Y-box binding protein 1 (YBX1) at the transcriptional and post-transcriptional levels. LINC00941 recruited ILF2 and YBX1 to the promoter region of SOX2, leading to upregulation of the transcription of SOX2. Moreover, LINC00941 could promote the binding ability of ILF2 and YBX1 on mRNA of SOX2 and further stabilize SOX2 mRNA. Therefore, LINC00941 contributed to the malignant behaviors of ESCC cells via the unrestricted increase in SOX2 expression. In conclusion, our data indicate that LINC00941 exacerbates ESCC progression through forming a LINC00941-ILF2/YBX1-SOX2 positive feedback loop, and LINC00941 may be a promising prognostic and therapeutic target for ESCC.

KTN1-AS1, a SOX2-mediated lncRNA, activates epithelial-mesenchymal transition process in esophageal squamous cell carcinoma.

Kinectin 1 antisense RNA 1 (KTN1-AS1), a long non-coding RNA (lncRNA), has been proved to have tumor-promoting properties and its expression is enhanced in several human tumors. However, the role of KTN1-AS1 in the pathogenesis of esophageal squamous cell carcinoma (ESCC) remains unknown. This study aimed to investigate the expression status, functional roles, and molecular mechanisms of KTN1-AS1 in the development of ESCC. Considerable upregulation of KTN1-AS1 was confirmed in esophageal cancer cells and ESCC tissues and its expression was associated with TNM stage, pathological differentiation, and lymph node metastasis. SOX2 directly activated transcription of KTN1-AS1, and overexpression of KTN1-AS1 facilitated ESCC cells proliferation and invasion in vitro and in vivo. Furthermore, KTN1-AS1 could bind to retinoblastoma binding protein 4 (RBBP4) in the nucleus and enhanced its binding with histone deacetylase 1 (HDAC1), thereby activating the epithelial-mesenchymal transition (EMT) process through downregulating E-cadherin expression at the epigenetic level. In conclusion, KTN1-AS1, induced by SOX2, acts as a tumor-promoting gene and may serve as a potential therapeutic and prognostic biomarker for ESCC.

The clinical prognostic value of long noncoding RNA HAND2-AS1 in cancer patients: A study based on meta-analysis and TCGA data (PRISMA).

BACKGROUND: The heart and neural crest derivatives expressed 2 antisense RNA 1 (HAND2-AS1) is a novel long noncoding RNA aberrantly expressed in human malignancies. We aimed to analyze the available data to evaluate the clinical prognostic significance of HAND2-AS1 in tumors. METHODS: In this meta-analysis, electronic databases, including PubMed Cochrane Library, EMBASE, Medline, Web of Science, CNKI, and Wanfang, were searched from their inception up to December 1, 2021. The pooled hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to assess the relationship of HAND2-AS1expression level with prognosis and clinicopathological features in cancer patients. The publication bias was identified by Begg's test, and the sensitivity analysis was also performed. RESULTS: A total of 10 articles with 615 patients were included in the present meta-analysis. The combined results revealed that low expression of HAND2-AS1 was associated with poor overall survival (OS) (HR = 0.48, 95% CI: 0.36-0.64, P < .001) in a variety of cancers. In addition, the decrease in HAND2-AS1 expression was also correlated with poor differentiation (OR = 4.36, 95% CI: 2.15-8.87, P < .001) and lymph node metastasis (OR = 0.26, 95% CI: 0.13-0.54, P < .001). The cancer genome atlas (TCGA) dataset further demonstrated that low expression of HAND2-AS1 was associated with poor OS and disease-free survival. CONCLUSIONS: Our results of this meta-analysis indicated that HAND2-AS1 may be a prognostic marker and even a therapeutic target for human cancer.

Long non-coding RNA NRSN2-AS1, transcribed by SOX2, promotes progression of esophageal squamous cell carcinoma by regulating the ubiquitin-degradation of PGK1.

Aberrant expression of long non-coding RNAs (lncRNAs) plays pivotal roles in tumorigenesis of human malignant cancers, including esophageal squamous cell carcinoma (ESCC). However, the specific role of lncRNA NRSN2-AS1 in ESCC has not been investigated. Our analysis of clinical data revealed that NRSN2-AS1 was upregulated in ESCC tissues and negatively correlated with patient survival. Luciferase reporter assays and chromatin immunoprecipitation assays demonstrated that NRSN2-AS1 is transcribed by SOX2. In vitro functional experiments showed that NRSN2-AS1 can promote ESCC cell proliferation, migration, and invasion. Furthermore, NRSN2-AS1-binding proteins were detected using RNA pull-down assays and mass spectrometry. Mechanistically, NRSN2-AS1 can bind to phosphoglycerate kinase 1 (PGK1) and upregulate its protein levels by inhibiting its ubiquitination. Knockdown of PGK1 in part abolished the NRSN2-AS1 overexpression-induced effects on ESCC cell proliferation, migration, invasion, and epithelial­mesenchymal transition (EMT). Thus, NRSN2-AS1 may be a diagnostic biomarker or treatment target for ESCC.

E2F1-activated NRSN2 promotes esophageal squamous cell carcinoma progression through AKT/mTOR pathway.

BACKGROUND: Neurensin­2 (NRSN2) has been reported to act as an oncogene in several types of human cancer. However, the molecular mechanism of NRSN2 in esophageal squamous cell carcinoma (ESCC) remains to be elucidated. METHODS: The mRNA expression levels of NRSN2 in ESCC tissues and cell lines were evaluated by quantitative real-time PCR (qRT-PCR). The protein expression levels of NRSN2 in ESCC tissues were measured by Immunohistochemical (IHC) method. Luciferase reporter and chromatin immunoprecipitation assays were conducted to confirm the upstream transcription factor of NRSN2. Loss- and gain-function assays were conducted to evaluate the effects of NRSN2 on ESCC cells proliferation, migration, and invasion. The function of NRSN2 was validated in vivo using tumor xenografts. The relationship between NRSN2 and AKT/mTOR pathway were confirmed by western blot assay. RESULTS: The expression level of NRSN2 was increased in ESCC tissues and cell lines. High expression level of NRSN2 was correlated with depth of invasion, lymph node metastasis, TNM stage, and poor prognosis of ESCC patients. NRSN2 was transcribed by E2F1. Knockdown of NRSN2 significantly inhibited ESCC cells proliferation, migration, and invasion, whereas NRSN2 overexpression showed reverse phenotypes. Overexpression of NRSN2 also enhanced ESCC tumorigenicity in vivo. Furthermore, the E2F1/NRSN2 axis promoted proliferation, migration, and invasion of ESCC cells by activating the AKT/mTOR pathway. CONCLUSION: NRSN2 is a direct transcriptional target of E2F1 to promote tumor progression in ESCC. NRSN2 may be a diagnostic biomarker or treatment target for ESCC.

Development and validation of a nomogram for prediction of cervical lymph node metastasis in middle and lower thoracic esophageal squamous cell carcinoma.

BACKGROUND: Estimates of cervical lymph node (LN) metastasis in patients with middle and lower thoracic esophageal squamous cell carcinoma (ESCC) are important. A nomogram is a useful tool for individualized prediction. METHODS: A total of 235 patients were enrolled in this study. Univariate and multivariate analyses were performed to screen for independent risk factors and construct a nomogram to predict the risk of cervical LN metastasis. The nomogram performance was assessed by discrimination, calibration, and clinical use. RESULTS: Totally, four independent predictors, including the maximum diameter of tumor, paraesophageal lymph node status, recurrent laryngeal nerve lymph node status, and the CT-reported cervical LN status, were enrolled in the nomogram. The AUC of the nomogram model in the training and validation dataset were 0.833 (95% CI 0.762-0.905), 0.808 (95% CI 0.696-0.920), respectively. The calibration curve demonstrated a strong consistency between nomogram and clinical findings in predicting cervical LN metastasis. Decision curve analysis demonstrated that the nomogram was clinically useful. CONCLUSION: We developed a nomogram that could be conveniently used to predict the individualized risk of cervical LN metastasis in patients with middle and lower thoracic ESCC.

Pharmacokinetics, oral bioavailability and metabolic analysis of solasodine in mice by dried blood spot LC-MS/MS and UHPLC-Q-Exactive MS.

Solasodine, a major ingredient in Solanaceae family, has various biological functions such as inducing neurogenesis, anticonvulsant and anti-tumor. Its risk assessment has also drawn public attention. However, little is known about its oral bioavailability and metabolic process. In this study, an liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of solasodine in mice dried blood spot (DBS) samples. To block nonspecific adsorption, DBS samples were pretreated with bovine serum albumin (BSA) and then extracted with ethyl acetate. This method was applied to a pharmacokinetic and bioavailability study of solasodine. The absolute bioavailability was only 1.28%. Thereafter, its metabolites in mice were characterized using an ultra-performance liquid chromatography Q-Exactive high-resolution mass spectrometer (UHPLC-QE-HRMS). Several isomeric metabolites were well separated and differentiated using their retention time, fragmentation pathways and correspondingly fragmentation rules of solasodine. As a result, 21 metabolites were characterized including 16 phase I and 5 phase II metabolites. The proposed metabolic pathways showed that solasodine mainly experienced oxidation, dehydration, dehydrogenation and sulfation. These results could help us to better understand the efficacy and safety of solasodine.

FOXD3 suppresses epithelial-mesenchymal transition through direct transcriptional promotion of SMAD7 in esophageal squamous cell carcinoma.

The transcription factor forkhead box D3 (FOXD3) is an important member of the FOX family, which can maintain the pluripotent properties of cell clusters, neural crest, and trophoblastic progenitor cells in vivo. It has been shown that FOXD3 could affect proliferation, migration, and angiogenesis of various tumors and its deletion and overexpression in organisms will undoubtedly have important influence on the change of cell fate and the occurrence of tumors. However, the underlying functions and molecular mechanisms of FOXD3 in esophageal squamous cell carcinoma (ESCC) have not been fully clarified. According to the present study, the expression levels and functional roles of FOXD3 were investigated, and its prognostic value and molecular mechanisms in tumorigenesis and progression of ESCC were clarified. The expression level of FOXD3 was significantly downregulated in ESCC tissues and cell lines, and correlated with gender, family history of upper gastrointestinal cancer, TNM stage, depth of invasion, lymph node metastasis, and ESCC patients' survival. Moreover, FOXD3 inhibited cells migration and invasion as well as participated in TGF-ß1 induced epithelial-mesenchymal transition process. Furthermore, a positive correlation between FOXD3 and SMAD family member 7 (SMAD7) was explored in ESCC. FOXD3 could directly bind to promoter regions of SMAD7 gene, leading to transcriptional promotion of SMAD7 in human esophageal cancer cells. Taken together, FOXD3 may play a tumor suppressor role in ESCC and may be applied as a new therapeutic target and prognostic marker for ESCC.