The status of phosphorylated p38 in esophageal squamous cell carcinoma

Traditional Chinese Medicine Therapy for Esophageal Cancer: A Literature Review

Esophageal cancer (EC) is the sixth leading cause of cancer-related deaths worldwide. Western medicine has played a leading role in its treatment, but its prognosis remains unsatisfactory. Therefore, the development of effective therapies is important. Traditional Chinese medicine (TCM) has been practiced for thousands of years, and involves taking measures before diseases occur, deteriorate, and recur. Interestingly, there is growing evidence that TCM can improve the therapeutic effects in reversing precancerous lesions, inhibiting the recurrence and metastasis of EC. In this article, we review traditional Chinese herbs and formulas that have preventive and therapeutic effects on EC, summarize the application and research status of TCM in patients with EC, and discuss its shortcomings and prospects in the context of translational, evidence-based, and precision medicine.

Proteomic variations of esophageal squamous cell carcinoma revealed by combining RNA-seq proteogenomics and G-PTM search strategy

BACKGROUND

Cancer that arises from epithelial cells of the esophagus is called esophagus squamous cell carcinoma (ESCC) and is mostly observed in developing nations. Evaluation of cancer genomes and its regulation into proteins plays a predominant role in understanding the cancer progressions. Mass-spectrometry-based proteomics is a consequential tool to estimate proteomic variation and posttranslational modifications (PTMs) from standard protein databases. Post-translational modifications play a crucial role in protein folding and PTMs can be accounted for as a biological signal to interpret the structural changes and transition order of proteins. Functional validation of cancer-related mutations can explain the effects of mutations on genes and the identification of Oncogenes and tumor suppressor genes. Therefore, we present a study on protein variations to interpret the structural changes and transition order of proteins in ESCC carcinogenesis.

METHODOLOGY

We are using a bottom-up proteomics approach with Galaxy-P framework and RNA sequence data analysis to generate the sample-specific databases containing details of RNA splicing and variant peptides. Once the database generated with information on variable modification, only the curated PTMs at specific positions are considered to perform spectral matching. Proteogenomics mapping was performed to identify protein variations in ESCC.

RESULTS

RNA-sequence proteogenomics with G-PTM (Global Post-Translational Modification) searching strategy has revealed proteomic events including several peptides that contain single amino acid variations, novel splice junction peptides and posttranslationally modified peptides. Proteogenomic mapping exhibited the splice junction peptides mapped predominantly for Malic enzyme exon type (ME-3) and MCM7 protein-coding genes that promote cancer progression, found to be exhibited in ESCC samples. Approximately 25 ± types of PTM modifications were recorded, and Protein Phosphorylation was largely noted.

CONCLUSION

ESCC cancer prognosis at the molecular level enables a better understanding of cancer carcinogenesis and protein modifications can be used as potential biomarkers.

Differences in Lipopolysaccharides-Induced Inflammatory Response Between Mouse Embryonic Fibroblasts and Bone Marrow-Derived Macrophages

Mouse embryonic fibroblasts (MEFs) are commonly used in research on the molecular mechanism(s) of inflammation because of its good response to inflammatory stimuli. However, the difference in inflammatory reaction between MEFs and macrophages, a classical inflammatory cell type, has not been identified. In this study, we report that both mRNA and protein levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in MEFs upon lipopolysaccharides (LPS) stimulation were significantly lower than those in bone marrow-derived macrophages (BMDMs). MAPK, NF-κB, and IRF3 pathways control the expression and production of inflammatory activated in LPS-stimulated MEFs, but showed different activation patterns in comparison with LPS-stimulated BMDMs. Upon LPS stimulation, activation of the MAPK pathway was slow and remarkably weaker in MEFs than that in BMDMs, whereas more pronounced activation of both NF-κB and IRF3 pathways was observed in MEFs compared to BMDMs. This difference in the activation of MAPK, NF-κB, and IRF3 pathways may result in different production of IL-6 and TNF-α between MEFs and BMDMs. We further revealed that substantial differences in more additional inflammatory response-related cytokines exist between LPS-stimulated MEFs and BMDMs. In conclusion, MEFs exhibit good responsiveness to LPS as a target cell for inflammation-related research. However, MEFs cannot replace macrophages because of substantial differences in their inflammatory reactivity.

Gossypetin is a novel MKK3 and MKK6 inhibitor that suppresses esophageal cancer growth in vitro and in vivo

Gossypetin as a hexahydroxylated flavonoid found in many flowers and Hibiscus. It exerts various pharmacological activities, including antioxidant, antibacterial and anticancer activities. However, the anticancer capacity of gossypetin has not been fully elucidated. In this study, gossypetin was found to inhibit anchorage-dependent and -independent growth of esophageal cancer cells. To identify the molecular target(s) of gossypetin, various signaling protein kinases were screened and results indicate that gossypetin strongly attenuates the MKK3/6-p38 signaling pathway by directly inhibiting MKK3 and MKK6 protein kinase activity in vitro. Mechanistic investigations showed that arginine-61 in MKK6 is critical for binding with gossypetin. Additionally, the inhibition of cell growth by gossypetin is dependent on the expression of MKK3 and MKK6. Gossypetin caused G2 phase cell cycle arrest and induced intrinsic apoptosis by activating caspases 3 and 7 and increasing the expression of BAX and cytochrome c. Notably, gossypetin suppressed patient-derived esophageal xenograft tumor growth in an in vivo mouse model. Our findings suggest that gossypetin is an MKK3 and MKK6 inhibitor that could be useful for preventing or treating esophageal cancer.

Residual tissue repositories as a resource for population-based cancer proteomic studies

BACKGROUND

Mass spectrometry-based proteomics has become a powerful tool for the identification and quantification of proteins from a wide variety of biological specimens. To date, the majority of studies utilizing tissue samples have been carried out on prospectively collected fresh frozen or optimal cutting temperature (OCT) embedded specimens. However, such specimens are often difficult to obtain, in limited in supply, and clinical information and outcomes on patients are inherently delayed as compared to banked samples. Annotated formalin fixed, paraffin embedded (FFPE) tumor tissue specimens are available for research use from a variety of tissue banks, such as from the surveillance, epidemiology and end results (SEER) registries' residual tissue repositories. Given the wealth of outcomes information associated with such samples, the reuse of archived FFPE blocks for deep proteomic characterization with mass spectrometry technologies would provide a valuable resource for population-based cancer studies. Further, due to the widespread availability of FFPE specimens, validation of specimen integrity opens the possibility for thousands of studies that can be conducted worldwide.

METHODS

To examine the suitability of the SEER repository tissues for proteomic and phosphoproteomic analysis, we analyzed 60 SEER patient samples, with time in storage ranging from 7 to 32 years; 60 samples with expression proteomics and 18 with phosphoproteomics, using isobaric labeling. Linear modeling and gene set enrichment analysis was used to evaluate the impacts of collection site and storage time.

RESULTS

All samples, regardless of age, yielded suitable protein mass after extraction for expression analysis and 18 samples yielded sufficient mass for phosphopeptide analysis. Although peptide, protein, and phosphopeptide identifications were reduced by 50, 20 and 76% respectively, from comparable OCT specimens, we found no statistically significant differences in protein quantitation correlating with collection site or specimen age. GSEA analysis of GO-term level measurements of protein abundance differences between FFPE and OCT embedded specimens suggest that the formalin fixation process may alter representation of protein categories in the resulting dataset.

CONCLUSIONS

These studies demonstrate that residual FFPE tissue specimens, of varying age and collection site, are a promising source of protein for proteomic investigations if paired with rigorously verified mass spectrometry workflows.

Down-regulation of long non-coding RNA ESCCAL_1 inhibits tumor growth of esophageal squamous cell carcinoma in a xenograft mouse model

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignant cancers with high incidence and mortality. Current reliable effective diagnostic and prognostic biomarkers are very limited in clinic. Emerging evidence indicates that dysregulated expression of the long non-coding RNAs (lncRNAs) was examined in various types of cancer including ESCC. ESCC associated lncRNA _1 (ESCCAL_1) was first time identified to be increased expression in ESCC, and therefore named by our research team. However, its potential function in the progression of ESCC remains unclear. In this study, we investigated the effect of ESCCAL_1 knockdown on ESCC tumorigenicity using a xenograft mouse model and explored the underlying molecular mechanism. Here we showed that ESCCAL_1 knockdown significantly inhibited EC9706 cell growth in nude mice. Interestingly, we also found that reduced expression of ESCCAL_1 resulted in distinct alterations of relative phosphorylation level of kinases (p-p38α, p-JNK, p-FAK and p-Src), and significant changes of the expression level of apoptosis-related proteins (p53, BAX, Bcl-2 and Caspase-3). In summary, our results suggest that lncRNA ESCCAL_1 is a potential diagnostic and prognostic target of ESCC.

Synergistic anticancer effect of combined crocetin and cisplatin on KYSE-150 cells via p53/p21 pathway

Background

More than 400,000 patients die from esophageal cancer annually. Considerable efforts have been made to develop new and effective treatments, one of which is directed toward herbal medication. Crocetin is a natural carotenoid dicarboxylic acid isolated from the Chinese herb saffron. We recently reported on the anticancer effects of saffron. This study aimed to determine whether crocetin combined cisplatin has synergistic effect in KYSE-150 cells and explore the underlying mechanism.

Methods

KYSE-150 cells were treated with crocetin and/or cisplatin. The effects on cell viability, cell apoptosis, mitochondrial membrane potential (MMP), as well as the expression levels of PI3K/AKT, MAPKs, p53/p21, and apoptosis-related protein were evaluated. MTT assay, Annexin V-FITC/PI staining, Rh123 staining, and Western blot analysis were used.

Results

The cell proliferation significantly decreased and cell apoptosis was induced with combined crocetin and cisplatin, compared with either crocetin only or cisplatin only. The outcome suggested that crocetin combined cisplatin has synergistic effects on inhibition of cell proliferation and pro-apoptotic effect of cisplatin on KYSE-150 cells. Disruption of MMP, upregulation of cleaved caspase-3 expression, and downregulation of Bcl-2 occurred in the group treated with combined treatment. No significant differences in p-PI3K, p-AKT, and MAPKs activity were indicated between combined treatment group and the individual treatment group. However, the expression levels of p53 and p21 were markedly higher in the combined treatment group than in the individual treatment group. The wild-type p53 inhibitor, PFT-α suppressed the overexpression of p53/p21 and the synergistic effect induced by the combination of crocetin and cisplatin.

Conclusions

We concluded that crocetin combined with cisplatin exerts a synergistic anticancer effect by up-regulating the p53/p21 pathway.

p38 predicts depression and poor outcome in esophageal cancer

p38 mitogen-activated protein kinase (MAPK) signaling has been implicated in the cancer development and progression. However, the precise mechanism of this association remains unknown. The aim of the present study was to evaluate the association between p38 and cancer progression, including investigations into the effects on cell proliferation, resistance to thalidomide, indoleamine 2,3-dioxygenase (IDO) expression and prognosis in patients with esophageal cancer. The present retrospective study included patients with stage I–III esophageal cancer. A total of 228 patients with esophageal cancer were recruited to analyze the expression of phosphorylated (p)-p38 and IDO in tumor, and normal tissues through immunohistochemistry. Depression status was measured using the Zung Self-Rating Depression Scale. P38 cDNA was transfected into esophageal cancer cells to assess tumor cell viability, sensitivity to thalidomide treatment and IDO gene expression. Western blotting and flow cytometry was used to analyze protein expression alterations, and apoptosis in esophageal cancer cells. P-p38 protein was expressed in 68.9% of cancer tissues, and was significantly associated with depressive symptoms, tumor recurrence and poor survival of patients. In vitro experiments revealed that the expression of p-p38 induced esophageal cancer Eca-109 and TE-1 cell viability, and resistance to thalidomide treatment, as well as in the expression of IDO without the application of lipopolysaccharides. Further follow-up of patients revealed that depression was also an independent factor for early recurrence and overall survival rate. Altered p38 MAPK expression was associated with poor outcome in patients with esophageal cancer. p38 may be a potential biomarker for the prediction of depressive symptoms and prognosis in patients with esophageal cancer.

IL-36α suppresses proliferation of ovarian cancer cells

Interleukin-36α (IL-36α), also formerly known as IL-1F6, is pertaining to IL-1 family members that has been shown to play an important pro-inflammatory role in chronic immune disorders. However, the role IL-36α in the setting of cancer remains unknown. Here, in our study, to investigate the clinical relevance of IL-36α in ovarian cancer, clinicopathological significance as well as expression level of IL-36α were analyzed in epithelial ovarian cancer clinical tissues and paired normal control. To explore the biological role of IL-36α in vitro in epithelial ovarian cancer cells, both overexpression and knockdown of IL-36α were performed. Based on the successful re-expression and silencing of IL-36α, proliferation, migration, and invasion were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound-healing, and Transwell assays, respectively. To further confirm the effect over proliferation in vivo, nude mice xenografted with epithelial ovarian cancer cells whose endogenous IL-36α was stably upregulated or downregulated were employed. It was found that IL-36α was shown to be markedly downregulated in epithelial ovarian cancer tissues relative to paired normal control and that reduced IL-36α expression was significantly associated with poor overall prognosis. In addition, IL-36α was observed to be able to suppress the growth of epithelial ovarian cancer cells both in vivo and in vitro. Taken together, IL-36α was displayed to be able to suppress the growth of epithelial ovarian cancer cells in our setting, which is suggestive of its druggable potential in curing the epithelial ovarian cancer and that upregulation of IL-36α was found to be capable of inhibiting the growth of epithelial ovarian cancer cells.

Initiation of esophageal squamous cell carcinoma (ESCC) in a murine 4-nitroquinoline-1-oxide and alcohol carcinogenesis model

Esophageal squamous cell carcinomas (ESCCs) are very common, aggressive tumors, and are often associated with alcohol and tobacco abuse. Because ESCCs exhibit high recurrence rates and are diagnosed at late stages, identification of prognostic and drug targets for prevention and treatment is critical. We used the 4-nitroquinoline-1-oxide (4-NQO) murine model of oral carcinogenesis and the Meadows-Cook model of alcohol abuse to assess changes in the expression of molecular markers during the initial stages of ESCC. Combining these two models, which mimic chronic alcohol and tobacco abuse in humans, we detected increased cellular proliferation (EGFR and Ki67 expression), increased canonical Wnt signaling and downstream elements (β-catenin, FoxM1, and S100a4 protein levels), changes in cellular adhesive properties (reduced E-cadherin in the basal layer of the esophageal epithelium), and increased levels of phosphorylated ERK1/2 and p38. Additionally, we found that treatment with ethanol alone increased the numbers of epithelial cells expressing solute carrier family 2 (facilitated glucose transporter, member 1) (SLC2A1) and carbonic anhydrase IX (CAIX), and increased the phosphorylation of p38. Thus, we identified both 4-NQO- and ethanol-specific targets in the initial stages of esophageal carcinogenesis, which should lead to the development of potential markers and therapeutic targets for human ESCC.

Overexpression of human β-defensin 2 promotes growth and invasion during esophageal carcinogenesis

Human β-defensin 2 (HBD-2) is an antimicrobial peptide produced by mucosal surfaces in response to microbial exposure or inflammatory cytokines. Although HBD-2 is expressed in the esophagus in response to stress and infectious agents, little is known regarding its expression and functional role in esophageal carcinogenesis. In the current investigation, normal esophagus and N-nitrosomethylbenzylamine (NMBA)-induced precancerous and papillomatous lesions of the rat esophagus were characterized for HBD-2 encoding gene Defb4 and protein. HBD-2 was found to be overexpressed in esophagi of rats treated with NMBA compared to animals in control group. Results of Real-time PCR, Western blot and immunohistochemistry demonstrated a positive correlation between the overexpression of HBD-2 and the progression of rat squamous cell carcinogenesis (SCC) in the esophagus. We also observed that HBD-2 is overexpressed in tumor tissues removed from patients with esophageal SCC. Moreover, Defb4 silencing in vitro suppresses the tumor cell proliferation, mobility and invasion in esophageal SCC cell line KYSE-150. The results from this study provide experimental evidence that HBD-2 may play an oncogenic role in the initiation and progression of esophageal SCC and thus serves as a target for chemopreventive and therapeutic interventions.