S100A4-MYH9 Axis Promote Migration and Invasion of Gastric Cancer Cells by Inducing TGF-β-Mediated Epithelial-Mesenchymal Transition

Hsp90 Promotes Gastric Cancer Cell Metastasis and Stemness by Regulating the Regional Distribution of Glycolysis-Related Metabolic Enzymes in the Cytoplasm

Heat-shock protein 90 (Hsp90) plays a crucial role in tumorigenesis and tumor progression; however, its mechanism of action in gastric cancer (GC) remains unclear. Here, the role of Hsp90 in GC metabolism is the focus of this research. High expression of Hsp90 in GC tissues can interact with glycolysis, collectively affecting prognosis in clinical samples. Both in vitro and in vivo experiments demonstrate that Hsp90 is able to regulate the migration and stemness properties of GC cells. Metabolic phenotype analyses indicate that Hsp90 influences glycolytic metabolism. Mechanistically, Hsp90 interacts with glycolysis-related enzymes, forming multienzyme complexes to enhance glycolysis efficiency and yield. Additionally, Hsp90 binds to cytoskeleton-related proteins, regulating the regional distribution of glycolytic enzymes at the cell margin and lamellar pseudopods. This effect could lead to a local increase in efficient energy supply from glycolysis, further promoting epithelial-mesenchymal transition (EMT) and metastasis. In summary, Hsp90, through its interaction with metabolic enzymes related to glycolysis, forms multi-enzyme complexes and regulates regional distribution of glycolysis by dynamic cytoskeletal adjustments, thereby promoting the migration and stemness of GC cells. These conclusions also support the potential for a combined targeted approach involving Hsp90, glycolysis, and the cytoskeleton in clinical therapy.

Non-Muscle Myosin II A: Friend or Foe in Cancer?

Non-muscle myosin IIA (NM IIA) is a motor protein that belongs to the myosin II family. The myosin heavy chain 9 (MYH9) gene encodes the heavy chain of NM IIA. NM IIA is a hexamer and contains three pairs of peptides, which include the dimer of heavy chains, essential light chains, and regulatory light chains. NM IIA is a part of the actomyosin complex that generates mechanical force and tension to carry out essential cellular functions, including adhesion, cytokinesis, migration, and the maintenance of cell shape and polarity. These functions are regulated via light and heavy chain phosphorylation at different amino acid residues. Apart from physiological functions, NM IIA is also linked to the development of cancer and genetic and neurological disorders. MYH9 gene mutations result in the development of several autosomal dominant disorders, such as May-Hegglin anomaly (MHA) and Epstein syndrome (EPS). Multiple studies have reported NM IIA as a tumor suppressor in melanoma and head and neck squamous cell carcinoma; however, studies also indicate that NM IIA is a critical player in promoting tumorigenesis, chemoradiotherapy resistance, and stemness. The ROCK-NM IIA pathway regulates cellular movement and shape via the control of cytoskeletal dynamics. In addition, the ROCK-NM IIA pathway is dysregulated in various solid tumors and leukemia. Currently, there are very few compounds targeting NM IIA, and most of these compounds are still being studied in preclinical models. This review provides comprehensive evidence highlighting the dual role of NM IIA in multiple cancer types and summarizes the signaling networks involved in tumorigenesis. Furthermore, we also discuss the role of NM IIA as a potential therapeutic target with a focus on the ROCK-NM IIA pathway.

Unveiling the enigmatic role of MYH9 in tumor biology: a comprehensive review

Non-muscle myosin heavy chain IIA (MYH9), a member of the non-muscle myosin II (NM II) family, is widely expressed in cells. The interaction of MYH9 with actin in the cytoplasm can hydrolyze ATP, completing the conversion of chemical energy to mechanical motion. MYH9 participates in various cellular processes, such as cell adhesion, migration, movement, and even signal transduction. Mutations in MYH9 are often associated with autosomal dominant platelet disorders and kidney diseases. Over the past decade, tumor-related research has gradually revealed a close relationship between MYH9 and the occurrence and development of tumors. This article provides a review of the research progress on the role of MYH9 in cancer regulation. We also discussed the anti-cancer effects of MYH9 under special circumstances, as well as its regulation of T cell function. In addition, given the importance of MYH9 as a key hub in oncogenic signal transduction, we summarize the current therapeutic strategies targeting MYH9 as well as the ongoing challenges.

Isotoosendanin inhibits triple-negative breast cancer metastasis by reducing mitochondrial fission and lamellipodia formation regulated by the Smad2/3-GOT2-MYH9 signaling axis

Triple-negative breast cancer (TNBC) is incurable and prone to widespread metastasis. Therefore, identification of key targets for TNBC progression is urgently needed. Our previous study revealed that isotoosendanin (ITSN) reduced TNBC metastasis by targeting TGFβR1. ITSN is currently used as an effective chemical probe to further discover the key molecules involved in TNBC metastasis downstream of TGFβR1. The results showed that GOT2 was the gene downstream of Smad2/3 and that ITSN decreased GOT2 expression by abrogating the activation of the TGF-β-Smad2/3 signaling pathway through directly binding to TGFβR1. GOT2 was highly expressed in TNBC, and its knockdown decreased TNBC metastasis. However, GOT2 overexpression reversed the inhibitory effect of ITSN on TNBC metastasis both in vitro and in vivo. GOT2 interacted with MYH9 and hindered its binding to the E3 ubiquitin ligase STUB1, thereby reducing MYH9 ubiquitination and degradation. Moreover, GOT2 also enhanced the translocation of MYH9 to mitochondria and thus induced DRP1 phosphorylation, thereby promoting mitochondrial fission and lamellipodia formation in TNBC cells. ITSN-mediated inhibition of mitochondrial fission and lamellipodia formation was associated with reduced GOT2 expression. In conclusion, ITSN prevented MYH9-regulated mitochondrial fission and lamellipodia formation in TNBC cells by enhancing MYH9 protein degradation through a reduction in GOT2 expression, thus contributing to its inhibition of TNBC metastasis.

Long-term survival in a patient with multiple metastatic gastric cancer treated with PTX plus emvolimab and disitamab vedotin: case report and treatment experience: A case report

RATIONALE

Most Chinese patients with locally advanced gastric cancer at diagnosis have an overall 5-year survival rate of <50%. Surgical resection alone is not suitable for patients with locally advanced gastric cancer. Currently, comprehensive treatment is the focus of locally advanced gastric cancer.

PATIENTS CONCERNS

The patient, a 56-year-old female, was admitted to the hospital because of "4 + months of double hydronephrosis found during a physical examination." Who was admitted for computer tomography and gastroscopy examinations, and take pathological tissue specimens during endoscopic examination.

DIAGNOSES

Computed tomography assessment indicated ulcerative gastric cancer with an abdominal implant, bladder, and bone metastases. An endoscopic examination revealed that the ulcer of the gastric angle was huge, and through relevant auxiliary examinations, the diagnosis of this disease is gastric cancer complicated with multiple metastases to bladder, rectum, lumbar spine, and peritoneum. Clinically diagnosed as cT4bN3M1.

INTERVENTIONS

The patient is currently undergoing first, second, and third line neoadjuvant therapy, combined with immunotherapy, targeted therapy, neoadjuvant intraperitoneal systemic chemotherapy, nutritional support, and other treatment plans.

OUTCOMES

After 15 cycles of treatment, the progression-free survival had reached 15 months. The patient had an NRS2002 score of 1, an ECOG score of I, a quality of life score of 55, albumin of 35.27 g/L, and a decrease in abdominal and pelvic fluid accumulation and exudation compared to before.

LESSONS

We demonstrated high survival of almost 3 years in a patient with gastric cancer that was complicated by bone, peritoneal, rectal, and bladder metastases. The combination of immunotherapy, targeted therapy, and neoadjuvant intraperitoneal systemic chemotherapy, along with the maintenance of nutritional status and CTCs could be a valuable modality for the subsequent treatment and observation of similar patients.

Claudin-18.2 mediated interaction of gastric Cancer cells and Cancer-associated fibroblasts drives tumor progression

BACKGROUND

Claudin-18.2 (CLDN18.2) has emerged as an alluring therapeutic target against gastrointestinal tumors in recent years. However, a thorough understanding of its regulatory mechanism in gastric cancer remains elusive.

METHODS

We presented a comprehensive study comprising 185 gastric cancer patients, which included 112 cases with high CLDN18.2 expression and 73 cases with low CLDN18.2 expression as determined by immunohistochemistry. After overdressed CLDN18.2 in AGS and NUGC4 cell lines, we elucidated the functions of CLDN18.2 in connecting gastric cancer cells and cancer-associated fibroblasts (CAFs) through an in vitro adhesion models and in vivo lung colonization models. The molecular mechanism underlying CLDN18.2-mediated interaction between gastric cancer cells and CAFs was identified through RNA sequencing and protein-proximity labeling techniques in vivo.

RESULTS

In our own cohort, a correlation was observed between high levels of CLDN18.2 expression and advanced cancer stage, poor prognosis, and heightened infiltration of CAFs. We elucidated a pivotal role of CLDN18.2 in mediating adhesion between gastric cancer cells and CAFs, which leads to the adhesion of cancer cells to stroma tissue and facilitates the clustering of cancer cells and CAFs into embolus, enhancing gastric cancer's metastatic progression and the risk of embolic death. Mechanistically, it was discovered that CAFs can activate adhesion and metastasis-related signaling pathways in CLDN18.2-positive gastric cancer cells. Furthermore, using an in vivo protein-proximity labeling approach, we identified S100 calcium binding protein A4 (S100A4) as a distinctive marker of CAFs that interacts with CLDN18.2 to enhance gastric cancer progression.

CONCLUSIONS

Our findings illuminated the role of the CLDN18.2-mediated interaction between cancer cells and CAFs in promoting gastric cancer progression and embolism, thereby providing insight into potential therapeutic avenues for CLDN18.2 positive cancers. Video Abstract.

Advances in RNAi therapies for gastric cancer: Targeting drug resistance and nanoscale delivery

Gastric cancer poses a significant health challenge, and exploring innovative therapeutic strategies is imperative. RNA interference (RNAi) has employed as an important therapeutic strategy for diseases by selectively targeting key pathways involved in diseases pathogenesis. Small interfering RNA (siRNA), a potent RNAi tool, possesses the capability to silence genes and downregulate their expression. This review provides a comprehensive examination of the potential applications of small interfering RNA (siRNA) and short hairpin RNA (shRNA), supplemented by an in-depth analysis of nanoscale delivery systems, in the context of gastric cancer treatment. The potential of siRNA to markedly diminish the proliferation and invasion of gastric cancer cells through the modulation of critical molecular pathways, including PI3K, Akt, and EMT, is highlighted. Besides, siRNA demonstrates its efficacy in inducing chemosensitivity in gastric tumor cells, thus impeding tumor progression. However, the translational potential of unmodified siRNA faces challenges, particularly in vivo and during clinical trials. To address this, we underscore the pivotal role of nanostructures in facilitating the delivery of siRNA to gastric cancer cells, effectively suppressing their progression and enhancing gene silencing efficiency. These siRNA-loaded nanoparticles exhibit robust internalization into gastric cancer cells, showcasing their potential to significantly reduce tumor progression. The translation of these findings into clinical trials holds promise for advancing the treatment of gastric cancer patients.

Molecular Insight into Gastric Cancer Invasion-Current Status and Future Directions

Gastric cancer (GC) is one of the most common malignancies worldwide. There has been no efficient therapy for stage IV GC patients due to this disease's heterogeneity and dissemination ability. Despite the rapid advancement of molecular targeted therapies, such as HER2 and immune checkpoint inhibitors, survival of GC patients is still unsatisfactory because the understanding of the mechanism of GC progression is still incomplete. Invasion is the most important feature of GC metastasis, which causes poor mortality in patients. Recently, genomic research has critically deepened our knowledge of which gene products are dysregulated in invasive GC. Furthermore, the study of the interaction of GC cells with the tumor microenvironment has emerged as a principal subject in driving invasion and metastasis. These results are expected to provide a profound knowledge of how biological molecules are implicated in GC development. This review summarizes the advances in our current understanding of the molecular mechanism of GC invasion. We also highlight the future directions of the invasion therapeutics of GC. Compared to conventional therapy using protease or molecular inhibitors alone, multi-therapy targeting invasion plasticity may seem to be an assuring direction for the progression of novel strategies.

ZC3H4 governs epithelial cell migration through ROCK/p-PYK2/p-MLC2 pathway in silica-induced pulmonary fibrosis

BACKGROUND

Increased epithelial migration capacity is a key step accompanying epithelial-mesenchymal transition (EMT). Our lab has described that ZC3H4 mediated EMT in silicosis. Here, we aimed to explore the mechanisms of ZC3H4 by which to stimulate epithelial cell migration.

METHODS

Silicon dioxide (SiO2)-induced pulmonary fibrosis (PF) animal models were administered by intratracheal instillation in C57BL/6 J mice. Pathological analysis and 2D migration assay were established to uncover the pulmonary fibrotic lesions and epithelial cell migration, respectively. Inhibitors targeting ROCK/p-PYK2/p-MLC2 and CRISPR/Cas9 plasmids targeting ZC3H4 were administrated to explore the signaling pathways.

RESULTS

1) SiO2 upregulated epithelial migration in pulmonary fibrotic lesions. 2) ZC3H4 modulated SiO2-induced epithelial migration. 3) ZC3H4 governed epithelial migration through ROCK/p-PYK2/p-MLC2 signaling pathway.

CONCLUSIONS

ZC3H4 regulates epithelial migration through the ROCK/p-PYK2/p-MLC2 signaling pathway, providing the possibility that molecular drugs targeting ZC3H4-overexpression may exert effects on pulmonary fibrosis induced by silica.

DNAJA4 suppresses epithelial-mesenchymal transition and metastasis in nasopharyngeal carcinoma via PSMD2-mediated MYH9 degradation

Emerging evidence indicates that DNA methylation plays an important role in the initiation and progression of nasopharyngeal carcinoma (NPC). DNAJA4 is hypermethylated in NPC, while its role in regulating NPC progression remains unclear. Here, we revealed that the promoter of DNAJA4 was hypermethylated and its expression was downregulated in NPC tissues and cells. Overexpression of DNAJA4 significantly suppressed NPC cell migration, invasion, and EMT in vitro, and markedly inhibited the inguinal lymph node metastasis and lung metastatic colonization in vivo, while it did not affect NPC cell viability and proliferation capability. Mechanistically, DNAJA4 facilitated MYH9 protein degradation via the ubiquitin-proteasome pathway by recruiting PSMD2. Furthermore, the suppressive effects of DNAJA4 on NPC cell migration, invasion, and EMT were reversed by overexpression of MYH9 in NPC cells. Clinically, a low level of DNAJA4 indicated poor prognosis and an increased probability of distant metastasis in NPC patients. Collectively, DNAJA4 serves as a crucial driver for NPC invasion and metastasis, and the DNAJA4-PSMD2-MYH9 axis might contain potential targets for NPC treatments.

Identification of MYH9 as a key regulator for synoviocyte migration and invasion through secretome profiling

OBJECTIVES

'Invasive pannus' is a pathological hallmark of rheumatoid arthritis (RA). This study aimed to investigate secretome profile of synovial fibroblasts of patients with RA (RA-FLSs), a major cell type comprising the invasive pannus.

METHODS

Secreted proteins from RA-FLSs were first identified using liquid chromatography-tandem mass spectrometry analysis. Ultrasonography was performed for affected joints to define synovitis severity at the time of arthrocentesis. Expression levels of myosin heavy chain 9 (MYH9) in RA-FLSs and synovial tissues were determined by ELISA, western blot analysis and immunostaining. A humanised synovitis model was induced in immuno-deficient mice.

RESULTS

We first identified 843 proteins secreted from RA-FLSs; 48.5% of the secretome was associated with pannus-driven pathologies. Parallel reaction monitoring analysis of the secretome facilitated discovery of 16 key proteins related to 'invasive pannus', including MYH9, in the synovial fluids, which represented synovial pathology based on ultrasonography and inflammatory activity in the joints. Particularly, MYH9, a key protein in actin-based cell motility, showed a strong correlation with fibroblastic activity in the transcriptome profile of RA synovia. Moreover, MYH9 expression was elevated in cultured RA-FLSs and RA synovium, and its secretion was induced by interleukin-1β, tumour necrosis factor α, toll-like receptor ligation and endoplasmic reticulum stimuli. Functional experiments demonstrated that MYH9 promoted migration and invasion of RA-FLSs in vitro and in a humanised synovitis model, which was substantially inhibited by blebbistatin, a specific MYH9 inhibitor.

CONCLUSIONS

This study provides a comprehensive resource of the RA-FLS-derived secretome and suggests that MYH9 represents a promising target for retarding abnormal migration and invasion of RA-FLSs.

HER2 inhibition increases non-muscle myosin IIA to promote tumorigenesis in HER2+ breast cancers

HER2 is over-expressed in around 15% to 20% of breast cancers. HER3 plays a critical role in HER2 mediated tumorigenesis. Increased HER3 transcription and protein levels occur upon inhibition of HER2. We aimed to identify proteins that bound to HER3 upon inhibition of the HER family with the pan-HER inhibitor neratinib in HER2+ breast cancer cells. Immunoprecipitation of HER3 followed by mass spectrometry experiments found non-muscle myosin IIA (NMIIA) increased upon neratinib treatment relative to vehicle DMSO treatment. MYH9 is the gene that encodes for the heavy chain of NMIIA. Breast cancer patients with high MYH9 were significantly associated with a shorter disease specific survival compared to patients with low MYH9 expression from the METABRIC cohort of patients. In addition, high MYH9 expression was associated with HER2+ tumors from this cohort. Immunoblots of whole cell lysates of BT474 and MDA-MB-453 HER2+ breast cancer cells demonstrated elevated HER3 and NMIIA protein levels upon neratinib treatment for 24 hours. To examine the role of NMIIA in HER2+ breast cancer, we modulated NMIIA levels in BT474 and MDA-MB-453 cells using doxycycline inducible shRNA targeting MYH9. MYH9 knockdown reduces HER3 protein levels and concomitant reduction in downstream P-Akt. In addition, loss of MYH9 suppresses cell growth, proliferation, migration, and invasion. Our data reveals that NMIIA regulates HER3 and loss of NMIIA reduces HER2+ breast cancer growth.

Pharmacological Inhibition of S100A4 Attenuates Fibroblast Activation and Renal Fibrosis

The TGF-β/Smad3 signaling pathway is an important process in the pathogenesis of kidney fibrosis. However, the molecular mechanisms are not completely elucidated. The current study examined the functional role of S100A4 in regulating TGF-β/Smad3 signaling in fibroblast activation and kidney fibrosis development. S100A4 was upregulated in the kidney in a murine model of renal fibrosis induced by folic acid nephropathy. Further, S100A4 was predominant in the tubulointerstitial cells of the kidney. Pharmacological inhibition of S100A4 with niclosamide significantly attenuated fibroblast activation, decreased collagen content, and reduced extracellular matrix protein expression in folic acid nephropathy. Overexpression of S100A4 in cultured renal fibroblasts significantly facilitated TGF-β1-induced activation of fibroblasts by increasing the expression of α-SMA, collagen-1 and fibronectin. In contrast, S100A4 knockdown prevented TGF-β1-induced activation of fibroblast and transcriptional activity of Smad3. Mechanistically, S100A4 interacts with Smad3 to stabilize the Smad3/Smad4 complex and promotes their translocation to the nucleus. In conclusion, S100A4 facilitates TGF-β signaling via interaction with Smad3 and promotes kidney fibrosis development. Manipulating S100A4 may provide a beneficial therapeutic strategy for chronic kidney disease.

CircSTX6 promotes pancreatic ductal adenocarcinoma progression by sponging miR-449b-5p and interacting with CUL2

BACKGROUND

circular RNAs (circRNAs) have been reported to play crucial roles in the biology of different cancers. However, little is known about the function of circSTX6 (hsa_circ_0007905) in pancreatic ductal adenocarcinoma (PDAC).

METHODS

circSTX6, a circRNA containing exons 4, 5, 6 and 7 of the STX6 gene, was identified by RNA sequencing and detected by quantitative reverse transcription PCR (qRT-PCR). The biological function of circSTX6 was assessed in vitro and in vivo. The relationship between circSTX6 and miR-449b-5p was confirmed by biotin-coupled circRNA capture, fluorescence in situ hybridization (FISH) and luciferase reporter assays. The interaction of circSTX6 with Cullin 2 (CUL2) was verified by RNA-protein RNA pull-down, RNA immunoprecipitation (RIP) and western blotting assays.

RESULTS

circSTX6 was frequently upregulated in PDAC tissues, and circSTX6 overexpression promoted tumor proliferation and metastasis both in vitro and in vivo. Furthermore, circSTX6 expression was associated with tumor differentiation and N stage. Mechanistically, circSTX6 regulated the expression of non-muscle myosin heavy chain 9 (MYH9) by sponging miR-449b-5p. Moreover, circSTX6 was confirmed to participate in the ubiquitin-dependent degradation of hypoxia-inducible factor 1-alpha (HIF1A) by interacting with CUL2 and subsequently accelerating the transcription of MYH9.

CONCLUSIONS

Our findings indicate that circSTX6 facilitates proliferation and metastasis of PDAC cells by regulating the expression of MYH9 through the circSTX6/miR-449b-5p axis and circSTX6/CUL2/HIF1A signaling pathway. Therefore, circSTX6 could serve as a potential therapeutic target for the treatment of PDAC.

Mitochondrial micropeptide STMP1 enhances mitochondrial fission to promote tumor metastasis

Micropeptides are a recently discovered class of molecules that play vital roles in various cellular processes, including differentiation, proliferation, and apoptosis. Here, we sought to identify cancer-associated micropeptides and to uncover their mechanistic functions. A micropeptide named short trans-membrane protein 1 (STMP1) that localizes at the inner mitochondrial membrane was identified to be upregulated in various cancer types and associated with metastasis and recurrence of hepatocellular carcinoma. Both gain- and loss-of-function studies revealed that STMP1 increased dynamin-related protein 1 (DRP1) activation to promote mitochondrial fission and enhanced migration of tumor cells. STMP1 silencing inhibited in vivo tumor metastasis in xenograft mouse models. Overexpression of STMP1 led to redistribution of mitochondria to the leading edge of cells and enhanced lamellipodia formation. Treatment with a DRP1 inhibitor abrogated the promotive effect of STMP1 on mitochondrial fission, lamellipodia formation, and tumor cell migration in vitro and metastasis in vivo. Furthermore, STMP1 interacted with myosin heavy chain 9 (MYH9), the subunit of non-muscle myosin II, and silencing MYH9 abrogated STMP1-induced DRP1 activation, mitochondrial fission, and cell migration. Collectively, this study identifies STMP1 as a critical regulator of metastasis and a novel unit of the mitochondrial fission protein machinery, providing a potential therapeutic target for treating metastases.

The significance of serum S100 calcium-binding protein A4 in silicosis

Background

Silicosis is a chronic occupational pulmonary disease characterized by persistent inflammation and irreversible fibrosis. Considerable evidences now indicate that S100 calcium-binding protein A4 (S100A4) has been associated with fibrotic diseases. However, the role of S100A4 in silicosis is still unclear.

Methods

In this study, serum levels of S100A4, transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) in patients with silicosis (n = 42) and control group (CG, n = 12) were measured by ELISA. S100A4 expression in lung tissues and primary alveolar macrophages (AMs) of mice with and without silicosis was detected by immunohistochemistry (IHC)/real-time PCR. The correlations between S100A4 and cytokines or lung function were assessed by Spearman's rank correlation analyses.

Results

Compared with CG, the levels of S100A4 were significantly increased in silicosis patients (70.84 (46.22, 102.46) ng/ml vs (49.84 (42.86, 60.02) ng/ml). The secretions of TGF-β1, CTGF, IL-6 and TNF-α in silicosis group were significantly higher than that in control group (p < 0.05). Serum S100A4 levels were positively correlated with TGF-β1 and IL-6, while were negatively correlated with lung function parameters including percentage of predicted forced vital capacity (FVC%pre), maximum vital capacity (Vcmax), deep inspiratory capacity (IC) and peak expiratory flow at 75% of vital capacity (PEF75). In receiver operating characteristic (ROC) analyses, S100A4 > 61.7 ng/ml had 63.4% sensitivity and 83.3% specificity for silicosis, and the area under the curve (AUC) was 0.707. Furthermore, immunostaining of lung tissues showed the accumulation of S100A4-positive cells in the areas of nodules of silicotic mice. The mRNA expression of S100A4 in the lung tissues and AMs of silicotic mice were significantly higher than controls.

Conclusion

These data suggested that increased S100A4 might contribute to the pathogenesis of silicosis.

Extracellular Vesicles Derived from SIPA1high Breast Cancer Cells Enhance Macrophage Infiltration and Cancer Metastasis through Myosin-9

Simple Summary

The high expression of signal-induced proliferation-associated 1 (SIPA1) in breast cancer could aggravate cancer cell metastasis, but how the tumour microenvironment is involved in this incident is unknown. In this study, we investigated whether breast cancer cells with high SIPA1 expression recruited macrophages into the tumour microenvironment. We also found that extracellular vesicles (EVs) derived from MDA-MB-231 cells significantly enhanced macrophage migration, compared with that from SIPA1-knockdown MDA-MB-231 cells both in vitro and in vivo. In terms of the mechanism, SIPA1 in cancer cells modulated the key protein myosin-9 in EVs and promoted macrophage infiltration via EVs. We confirmed that either down-regulating SIPA1 expression or blocking myosin-9 by its inhibitor, blebbistatin, led to the suppression of macrophage infiltration. These findings contribute to a deep understanding of how SIPA1 regulates the tumour microenvironment in breast cancer to facilitate tumour metastasis and provide a basis for the development of therapeutics against breast cancer metastasis.

Abstract

Tumour cell metastasis can be genetically regulated by proteins contained in cancer cell-derived extracellular vesicles (EVs) released to the tumour microenvironment. Here, we found that the number of infiltrated macrophages was positively correlated with the expression of signal-induced proliferation-associated 1 (SIPA1) in invasive breast ductal carcinoma tissues and MDA-MB-231 xenograft tumours. EVs derived from MDA-MB-231 cells (231-EVs) significantly enhanced macrophage migration, compared with that from SIPA1-knockdown MDA-MB-231 cells (231/si-EVs) both in vitro and in vivo. We revealed that SIPA1 promoted the transcription of MYH9, which encodes myosin-9, and up-regulated the expression level of myosin-9 in breast cancer cells and their EVs. We also found that blocking myosin-9 by either down-regulating SIPA1 expression or blebbistatin treatment led to the suppression of macrophage infiltration. Survival analysis showed that breast cancer patients with high expression of SIPA1 and MYH9 molecules had worse relapse-free survival (p = 0.028). In summary, SIPA1^high breast cancer can enhance macrophage infiltration through EVs enriched with myosin-9, which might aggravate the malignancy of breast cancer.

circ-EIF6 encodes EIF6-224aa to promote TNBC progression via stabilizing MYH9 and activating the Wnt/beta-catenin pathway

The protein-coding ability of circular RNAs (circRNAs) has recently been a hot topic, but the expression and roles of protein-coding circRNAs in triple-negative breast cancer (TNBC) remain uncertain. By intersecting circRNA sequencing data from clinical samples and cell lines, we identified a circRNA, termed circ-EIF6, which predicted a poorer prognosis and correlated with clinicopathological characteristics in a cohort of TNBC patients. Functionally, we showed that circ-EIF6 promoted the proliferation and metastasis of TNBC cells in vitro and in vivo. Mechanistically, we found that circ-EIF6 contains a 675-nucleotide (nt) open reading frame (ORF) and that the -150-bp sequence from ATG functioned as an internal ribosome entry site (IRES), which is required for translation initiation in 5' cap-independent coding RNAs. circ-EIF6 encodes a novel peptide, termed EIF6-224 amino acid (aa), which is responsible for the oncogenic effects of circ-EIF6. The endogenous expression of EIF6-224aa was further examined in TNBC cells and tissues by specific antibody. Moreover, EIF6-224aa directly interacted with MYH9, an oncogene in breast cancer, and decreased MYH9 degradation by inhibiting the ubiquitin-proteasome pathway and subsequently activating the Wnt/beta-catenin pathway. Our study provided novel insights into the roles of protein-coding circRNAs and supported circ-EIF6/EIF6-224aa as a novel promising prognostic and therapeutic target for tailored therapy in TNBC patients.

An age stratified analysis of the biomarkers in patients with colorectal cancer

Colorectal cancer (CRC), a common malignant tumor of the digestive tract, has a high incidence and mortality rate. Several recent studies have found that aging is associated with the increasing risk of cancer. Nevertheless, the expression status and function of age-related genes in CRC is still not well understood. In the study, we comprehensively analyzed the gene expression data of CRC patients from The Cancer Genome Atlas (TCGA) database. Age-related differential expression genes (age-related DEGs) in tumor tissues compared with normal tissues of CRC were further identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of age-related DEGs were performed by clusterProfiler of R. Afterwards, we used the STRING database to map the protein-protein interaction network of DEGs. We constructed prognostic model through univariate and multivariate COX regression analyses, and further evaluated their predictive power. The prognostic gene signature-related functional pathways were explored by gene set enrichment analysis (GSEA). The weighted gene co-expression network analysis (WGCNA) was used to identify key module associated with two prognostic gene signatures. Finally, we used the Metascape to perform functional enrichment analysis of genes in the key module. A total of 279 age-related DEGs were identified from the TCGA database. GO and KEGG enrichment analysis showed that the age-related DEGs were enriched in the Modulation of chemical synaptic transmission and Neuroactive ligand-receptor interaction. Moreover, we established a novel age-related gene signature (DLX2 and PCOLCE2) for overall survival in CRC, which was further predicted in both the training and validation sets. The results of GSEA demonstrated that numerous disease-related pathways were enriched in the high-risk group. We identified 43 genes related to the DLX2 and PCOLCE2 by the WGCNA co-expression network. We also found that these 43 genes were enriched in the cancer-related pathways. To sum up, the study identified an age-related gene signature for predicting the prognosis of CRC patients, which is conducive to the identification of novel prognostic molecular markers.

Changes in the expression and functional activities of Myosin II isoforms in human hyperplastic prostate

Benign prostatic hyperplasia (BPH) is a common disease among aging males with the etiology remaining unclear. We recently found myosin II was abundantly expressed in rat and cultured human prostate cells with permissive roles in the dynamic and static components. The present study aimed to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in the hyperplastic prostate. Human prostate cell lines and tissues from normal human and BPH patients were used. Hematoxylin and Eosin (H&E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. We further created cell models with NMM II isoforms silenced and proliferation, cycle, and apoptosis of prostate cells were determined by cell counting kit-8 (CCK-8) assay and flow cytometry. Hyperplastic prostate SM expressed more SM1 and LC17b isoforms compared with their alternatively spliced counterparts, favoring a slower more tonic-type contraction and greater force generation. For BPH group, blebbistatin (BLEB, a selective myosin II inhibitor), exhibited a stronger effect on relaxing phenylephrine (PE) pre-contracted prostate strips and inhibiting PE-induced contraction. Additionally, NMMHC-A and NMMHC-B were up-regulated in hyperplastic prostate with no change in NMMHC-C. Knockdown of NMMHC-A or NMMHC-B inhibited prostate cell proliferation and induced apoptosis, with no changes in cell cycle. Our novel data demonstrate that expression and functional activities of myosin II isoforms are altered in human hyperplastic prostate, suggesting a new pathological mechanism for BPH. Thus, the myosin II system may provide potential new therapeutic targets for BPH/lower urinary tract symptoms (LUTS).

Long noncoding RNA ERLR mediates epithelial-mesenchymal transition of retinal pigment epithelial cells and promotes experimental proliferative vitreoretinopathy

Proliferative vitreoretinopathy (PVR) is a disease that causes severe blindness and is characterized by the formation of contractile fibrotic subretinal or epiretinal membranes. The epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is a hallmark of PVR. This work aims to examine the role of a long noncoding RNA (lncRNA) named EMT-related lncRNA in RPE (ERLR, LINC01705-201 (ENST00000438158.1)) in PVR and to explore the underlying mechanisms. In this study, we found that ERLR is upregulated in RPE cells stimulated with transforming growth factor (TGF)-β1 as detected by lncRNA microarray and RT-PCR. Further studies characterized full-length ERLR and confirmed that it is mainly expressed in the cytoplasm. In vitro, silencing ERLR in RPE cells attenuated TGF-β1-induced EMT, whereas overexpressing ERLR directly triggered EMT in RPE cells. In vivo, inhibiting ERLR in RPE cells reduced the ability of cells to induce experimental PVR. Mechanistically, chromatin immunoprecipitation (ChIP) assays indicated that the transcription factor TCF4 directly binds to the promoter region of ERLR and promotes its transcription. ERLR mediates EMT by directly binding to MYH9 protein and increasing its stability. TCF4 and MYH9 also mediate TGF-β1-induced EMT in RPE cells. Furthermore, ERLR is also significantly increased in RPE cells incubated with vitreous PVR samples. In clinical samples of PVR membranes, ERLR was detected through fluorescent in situ hybridization (FISH) and colocalized with the RPE marker pancytokeratin (pan-CK). These results indicated that lncRNA ERLR is involved in TGF-β1-induced EMT of human RPE cells and that it is involved in PVR. This finding provides new insights into the mechanism and treatment of PVR.

Helicobacter urease suppresses cytotoxic CD8 + T cell responses through activating Myh9-dependent induction of PD-L1

As a key virulence factor for persistent colonization, Urease B subunit (UreB) is considered to be an ideal vaccine antigen against Helicobacter pylori (H. pylori) infection. However, the role and molecular mechanisms of UreB involved in immune microenvironment dysregulation still remains largely unknown. In the present study, we evaluated the effects of UreB on macrophage activation and found that UreB induced PD-L1 accumulation on Bone marrow-derived macrophages (BMDMs). Co-culture assays further revealed that UreB-induced PD-L1 expression on BMDMs significantly decreased the proliferation and secretion of cytolytic molecules (granzyme B and perforin) of splenic CD8 + T cells isolated from inactivated H. pylori-immunized mice. More importantly, myosin heavy chain 9 (Myh9) was confirmed to be a direct membrane receptor of UreB via using LC-MS/MS and Co-immunoprecipitation and required for PD-L1 upregulation on BMDMs. Molecular studies further demonstrated that the interaction between UreB and Myh9 decreased GCN2 autophosphorylation and enhanced intracellular pool of amino acids, leading to the upregulation of S6K phosphorylation, a commonly used marker for monitoring activation of mTORC1 signaling activity. Furthermore, blocking mTORC1 activation with its inhibitor Temsirolimus reversed UreB-induced PD-L1 upregulation and the subsequently inhibitory effects of BMDMs on activation of cytotoxic CD8 + T cell responses. Overall, our data unveil a novel immunosuppressive mechanism of UreB during H. pylori infection, which may provide valuable clue for the optimization of H. pylori vaccine.

MYH9-dependent polarization of ATG9B promotes colorectal cancer metastasis by accelerating focal adhesion assembly

Tumour metastasis is a major reason accounting for the poor prognosis of colorectal cancer (CRC), and the discovery of targets in the primary tumours that can predict the risk of CRC metastasis is now urgently needed. In this study, we identified autophagy-related protein 9B (ATG9B) as a key potential target gene for CRC metastasis. High expression of ATG9B in tumour significantly increased the risk of metastasis and poor prognosis of CRC. Mechanistically, we further find that ATG9B promoted CRC invasion mainly through autophagy-independent manner. MYH9 is the pivotal interacting protein for ATG9B functioning, which directly binds to cytoplasmic peptide segments aa368-411 of ATG9B by its head domain. Furthermore, the combination of ATG9B and MYH9 enhance the stability of each other by decreasing their binding to E3 ubiquitin ligase STUB1, therefore preventing them from ubiquitin-mediated degradation, which further amplified the effect of ATG9B and MYH9 in CRC cells. During CRC cell invasion, ATG9B is transported to the cell edge with the assistance of MYH9 and accelerates focal adhesion (FA) assembly through mediating the interaction of endocytosed integrin β1 and Talin-1, which facilitated to integrin β1 activation. Clinically, upregulated expression of ATG9B in human CRC tissue is always accompanied with highly elevated expression of MYH9 and associated with advanced CRC stage and poor prognosis. Taken together, this study highlighted the important role of ATG9B in CRC metastasis by promoting focal adhesion assembly, and ATG9B together with MYH9 can provide a pair of potential therapeutic targets for preventing CRC progression.

LINC00665 promotes cell proliferation, invasion, and metastasis by activating the TGF-β pathway in gastric cancer

BACKGROUND AND AIMS

Accumulating studies have demonstrated that long noncoding RNA plays a vital role in cancer progression. A previous study reported that LINC00665 was overexpressed and acted as a key tumor promoter in lung cancer, but the role of LINC00665 in gastric cancer (GC) remained uncharacterized. Thus, this study aimed to explore the mechanism of LINC00665 in GC.

METHODS

LINC00665 expression was explored using the Cancer Genome Atlas (TCGA), and a meta-analysis was conducted to assess the expression and prognostic value of LINC00665 in GC from Gene Expression Omnibus databases and the TCGA dataset. Real-time polymerase chain reaction (RT-PCR) was then conducted to verify the LINC00665 expression in GC tissues and cell lines. The effects of LINC00665 on cell proliferation, invasion, metastasis, and cell cycle in GC were evaluated using the CCK-8, wound healing, Transwell, and flow cytometry assays. In vitro validation was also performed.

RESULTS

LINC00665 overexpression was found in GC, and LINC00665 upregulation was significantly related to poor overall survival and disease-free survival. LINC00665 expression was associated with tumor depth, lymph node metastasis, and TNM stage. Univariate and multivariate analyses proved that LINC00665 could be an independent prognostic biomarker in GC. LINC00665 knockdown subsequently inhibited cell proliferation, invasion, and metastasis in GC cell lines; promoted cell apoptosis; and arrested GC cell lines in the G0/G1 phase. Western blot analysis indicated that LINC00665 silencing inhibited epithelial-mesenchymal transition and decreased the expression levels of TGF-β1, Smad2, and α-SMA.

CONCLUSION

LINC00665 can be a potential diagnostic and prognostic biomarker for GC patients, and LINC00665 promotes GC cell proliferation, invasion, and metastasis by activating the TGF-β signal pathway.

The Overexpression of NMHC IIA Promoted Invasion and Metastasis of Nasopharyngeal Carcinoma Cells

Background: Nasopharyngeal carcinoma (NPC) is a kind of head and neck squamous cell carcinoma (HNSCC) with a strong tendency for metastasis and recurrence. Non-muscle myosin heavy chain IIA (NMHC IIA) plays important roles in recurrence and metastasis of cancers. However, the function and mechanism of NMHC IIA expression in NPC remain unclear. Methods: A receiver operating characteristic (ROC) curve was constructed for 141 specimens of HNSCC tissues and 44 control samples from The Cancer Genome Atlas (TCGA) database. Co-expressed genes with MYH9 were identified using LinkedOmics. Transcription factors (TFs) and miRNA regulation network were constructed using Networkanalyst. The migration and invasion ability of nasopharyngeal carcinoma cells were evaluated by in vitro migration and matrigel invasion assays, respectively. Results: The public microarray results showed that MYH9 expression levels were upregulated in HNSCC tissues compared with the matched adjacent normal tissues in this study (p<0.0001). The AUC of MYH9 reached up to 0.8303 at a cutoff value of 175.2, with a sensitivity and specificity of 70.21% and 86.36%, respectively. MYH9 expression was increased in lymph node metastasis HNSCC tumors compared with that in tumors without lymph node metastasis (p<0.05) and showed a strong positive association with expression of FLNA. High MYH9 and FLNA expression were related with poorer overall survival in HNSCC. MYH9 with positively associated genes regulated focal adhesion, cell-substrate junction assembly and cell morphogenesis were involved in differentiation using GO and KEGG analysis. MYH9 was correlated with a network of TFs including SP1, SRF, JUN and FOS in HNSCC. The suppression of endogenous NMHC IIA decreased cellular migration and invasion in HNE1 cells and reduced the expression of phosphorylation of EGFR, AKT and ERK. The over-expression of NMHC IIA increased cellular migration and invasion in COS-7 cells and increased the expression of phosphorylation of EGFR, AKT and ERK. Conclusion: Expression of NMHC IIA mRNA was higher in HNSCC than in the adjacent normal tissues. NMHC IIA expression was increased in lymph node metastasis HNSCC tumors compared with tumors without lymph node metastasis. High MYH9 was association with poorer overall survival in HNSCC. NMHC IIA expression increased the invasion and metastasis abilities of the nasopharyngeal cancer cell line in vitro by augmenting the expression of phosphorylation of EGFR, AKT and ERK. These findings will be beneficial for providing an effectively therapeutic strategy for NPC.

Involvement of cancer-derived EMT cells in the accumulation of 18F-fluorodeoxyglucose in the hypoxic cancer microenvironment

A high rate of glycolysis, one of the most common features of cancer, is used in positron emission tomography (PET) imaging to visualize tumor tissues using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG). Heterogeneous intratumoral distribution of ¹⁸F-FDG in tissues has been established in some types of cancer, and the maximum standardized uptake value (SUVmax) has been correlated with poor prognosis. However, the phenotype of cells that show high ¹⁸F-FDG accumulation in tumors remains unknown. Here, we combined quantitative micro-autoradiography with fluorescence immunohistochemistry to simultaneously visualize ¹⁸F-FDG distribution, the expression of multiple proteins, and hypoxic regions in the cancer microenvironment of a human A431 xenograft tumor in C.B-17/Icr-scid/scid mice. We found that the highest ¹⁸F-FDG accumulation was in cancer-derived cells undergoing epithelial-mesenchymal transition (EMT) in hypoxic regions, implicating these regions as a major contributor to increased glucose metabolism, as measured by ¹⁸F-FDG-PET.

5-Aza-2'-Deoxycytidine and Valproic Acid in Combination with CHIR99021 and A83-01 Induce Pluripotency Genes Expression in Human Adult Somatic Cells

A generation of induced pluripotent stem cells (iPSC) by ectopic expression of OCT4, SOX2, KLF4, and c-MYC has established promising opportunities for stem cell research, drug discovery, and disease modeling. While this forced genetic expression represents an advantage, there will always be an issue with genomic instability and transient pluripotency genes reactivation that might preclude their clinical application. During the reprogramming process, a somatic cell must undergo several epigenetic modifications to induce groups of genes capable of reactivating the endogenous pluripotency core. Here, looking to increase the reprograming efficiency in somatic cells, we evaluated the effect of epigenetic molecules 5-aza-2'-deoxycytidine (5AZ) and valproic acid (VPA) and two small molecules reported as reprogramming enhancers, CHIR99021 and A83-01, on the expression of pluripotency genes and the methylation profile of the OCT4 promoter in a human dermal fibroblasts cell strain. The addition of this cocktail to culture medium increased the expression of OCT4, SOX2, and KLF4 expression by 2.1-fold, 8.5-fold, and 2-fold, respectively, with respect to controls; concomitantly, a reduction in methylated CpG sites in OCT4 promoter region was observed. The epigenetic cocktail also induced the expression of the metastasis-associated gene S100A4. However, the epigenetic cocktail did not induce the morphological changes characteristic of the reprogramming process. In summary, 5AZ, VPA, CHIR99021, and A83-01 induced the expression of OCT4 and SOX2, two critical genes for iPSC. Future studies will allow us to precise the mechanisms by which these compounds exert their reprogramming effects.

The DDX39B/FUT3/TGFβR-I axis promotes tumor metastasis and EMT in colorectal cancer

DDX39B is a member of the DEAD box (DDX) RNA helicase family required for nearly all cellular RNA metabolic processes. The exact role and potential molecular mechanism of DDX39B in the progression of human colorectal cancer (CRC) remain to be investigated. In the present study, we demonstrate that DDX39B expression is higher in CRC tissues than in adjacent normal tissues. Gain- and loss-of-function assays revealed that DDX39B facilitates CRC metastasis in vivo and in vitro. Mechanistically, RNA-sequencing (RNA-seq) and RNA-binding protein immunoprecipitation-sequencing (RIP-seq) showed that DDX39B binds directly to the FUT3 pre-mRNA and upregulates FUT3 expression. Splicing experiments in vitro using a Minigene assay confirmed that DDX39B promotes FUT3 pre-mRNA splicing. A nuclear and cytoplasmic RNA separation assay indicates that DDX39B enhances the mRNA export of FUT3. Upregulation of FUT3 accelerates the fucosylation of TGFβR-I, which activates the TGFβ signaling pathway and eventually drives the epithelial–mesenchymal transition (EMT) program and contributes to CRC progression. These findings not only provide new insight into the role of DDX39B in mRNA splicing and export as well as in tumorigenesis, but also shed light on the effects of aberrant fucosylation on CRC progression.

Aminated Fullerene Abrogates Cancer Cell Migration by Directly Targeting Myosin Heavy Chain 9

Functional fullerene derivatives exhibit fantastic inhibitory capabilities against cancer survival and metastasis, but the absence of clarified biological molecular targets and ambiguous regulation mechanisms set barriers for their clinical transformation. Cancer metastasis is the primary cause of mortality and initiated with increased cell migration, making cell motility regulation a high-value therapeutic target in precision medicine. Herein, a critical molecular target of the aminated fullerene derivative (C₇₀-EDA), myosin heavy chain 9 (MYH9), was initially identified by a pull-down assay and MS screening. MYH9 is a cytoplasm-located protein and is responsible for cell motility and epithelial-mesenchymal transition regulation. Omics data from large-scale clinical samples reveals that MYH9 gets overexpressed in various cancers and correlates with unfavorable prognosis, indicating that it is a potential antineoplastic target. It is unveiled that C₇₀-EDA binds to the C-terminal of MYH9, triggering the transport of MYH9 from the cytoplasm to the cell edge, blocking the MYH9-involved cell mobility, and inhibiting the metastasis-associated EMT process. This work provides a precise biological target and new strategies for fullerene applications in cancer therapy.

Long non-coding RNA LOC285194 inhibits proliferation and migration but promoted apoptosis in vascular smooth muscle cells via targeting miR-211/PUMA and TGF-β1/S100A4 signal

Long non-coding RNA LOC285194 (LOC285194) has reported to regulate vascular smooth muscle cells (VSMCs) proliferation and apoptosis in vitro and in vivo. Here we aimed to determine the role of LOC285194 in the proliferation, migration and apoptosis of VSMCs and its underlying mechanisms. A7r5 cells were transfected with Lv-LOC285194 or control Lv-NC for 24-72 h, or small interfering RNA targeting S100A4 (S100A4 siRNA) for 24-48 h, or co-transfected with Lv-LOC285194 and PUMA siRNA for 72 h, or treated with miR-211 inhibitor or co-transfected with Lv-LOC285194 and miR-211 mimics for 72 h. A7r5 cells were also treated with transforming growth factor - β(TGF-β) (5 ng/ml) after Lv-LOC285194 transfection for 24 h. The relationship between LOC285194 and TGF-β was confirmed using luciferase reporter assay. Cell proliferation and cell apoptosis were analyzed by Cell Counting Kit-8 (CCK-8) assay, ELISA and TUNEL staining. LOC285194 and miR-211 expression were detected by qPCR assay. S100A4, pro-apoptotic and anti-apoptotic protein were detected by Western blot assay. LOC285194 inhibited cell proliferation, invasion and migration and promoted cell apoptosis accompanied by upregulation of PUMA and downregulation of miR-211 and S100A4. Targeting PUMA reversed the effect of LOC285194 on cell apoptosis and proliferation. miR-211 mimic inhibited LOC285194-induced PUMA upregulation and decreased LOC285194-induced cell apoptosis. TGF-β (5 ng/ml) treatment reversed S100A4 siRNA or LOC285194-induced S100A4 expression. Luciferase reporter assay showed that TGF-β was the target of LOC285194. LOC285194 inhibits proliferation and promoted apoptosis in vascular smooth muscle cells via targeting miR-211/PUMA signal; In addition, LOC285194 decreased cell invasion and migration by targeting TGF-β1/S100A4 signal.

Molecular biology and immunology of gastric cancer peritoneal metastasis

Peritoneal metastases occur in 55-60% of patients with gastric cancer (GC) and are associated with a 2% 5-year overall survival rate. There are limited treatment options for these patients, and no targeted therapy or immunotherapy is available. Rational therapeutic targets remain to be found. In this review, we present the published literature and our own recent experience in molecular biology to identify important molecules and signaling pathways as well as cellular immunity involved in the peritoneal metastasis of GC. We also suggest potential novel strategies for improving the outcomes of GC patients with peritoneal metastasis.

Knockdown of ferritin heavy chain (FTH) inhibits the migration of prostate cancer through reducing S100A4, S100A2, and S100P expression

BACKGROUND

Ferritin plays a key role in the development of prostate cancer (PCa). Our earlier studies showed that the knockdown of ferritin heavy chain (FTH) suppressed the migration and invasion of the prostate cancer cell line (PC3). However, the mechanisms behind FTH in the cell migration regulation of PCa have not been thoroughly investigated.

METHODS

Isobaric tags for relative and absolute quantitation (iTRAQ) proteomics was used to analyze the protein expression in PC3 cells with FTH knockdown by small interfering RNAs and negative control cells. We subsequently ranked the differentially expressed proteins according to the change in expression. We further performed Gene Ontology (GO) analysis for the changing-expression protein. Finally, Western blot analysis was performed to determine the expression of the target protein.

RESULTS

Compared with the negative group, 420 proteins were downregulated, including proteins S100A4, S100P, and S100A2, while the expression of 442 protein was elevated in FTH-silencing PC3 cells (P<0.05, fold change >1.2). The mass spectrometry results showing decreased expression of protein S100A4, S100P, and S100A2 in the cells were further validated by Western blot (P<0.05). Levels of protein S100A4, S100A2, and S100P were reduced in FTH-silencing PC3 cells (P<0.05, fold change >1.6).

CONCLUSIONS

The downregulation of FTH expression reduced the level of protein S100A4, S100A2, and S100P, which all play a key role in the migration and invasion of tumor cells. Therefore, it is reasonable to assume that there are correlations between the expression of the S100A4, S100A2, and S100P genes with FTH. Based on this research, FTH may be a new biomarker for the diagnosis of PCa.

FNDC3B 3'-UTR shortening escapes from microRNA-mediated gene repression and promotes nasopharyngeal carcinoma progression

Alternative polyadenylation (APA), which induces shortening of the 3'-UTR, is emerging as an important feature in cancer development and progression. Nevertheless, the effects and mechanisms of APA-induced 3'-UTR shortening in nasopharyngeal carcinoma (NPC) remain largely unclear. Fibronectin type III domain containing 3B (FNDC3B) tended to use proximal polyadenylation site and produce shorter 3'-UTR according to our previous sequencing study. Herein, we found that FNDC3B with shorter 3'-UTR could escape from miRNA-mediated gene repression, and caused its increased expression in NPC. Knocking down of FNDC3B inhibited NPC cell proliferation, migration, invasion, and metastasis in vitro and in vivo. Overexpression of FNDC3B, especially those with shorter 3'-UTR, promoted NPC progression. Furthermore, the mechanism study revealed that FNDC3B could bind to and stabilize myosin heavy chain 9 (MYH9) to activate the Wnt/β-catenin signaling pathway. In addition, MYH9 could reverse the inhibitory effects of FNDC3B knockdown in NPC. Altogether, our results suggested that the 3'-UTR shortening of FNDC3B mRNA mediated its overexpression in NPC and promoted NPC progression by targeting MYH9. This newly identified FNDC3B-MYH9-Wnt/β-catenin axis could represent potential targets for individualized treatment in NPC.

Silencing MYH9 blocks HBx-induced GSK3β ubiquitination and degradation to inhibit tumor stemness in hepatocellular carcinoma

MYH9 has dual functions in tumors. However, its role in inducing tumor stemness in hepatocellular carcinoma (HCC) is not yet determined. Here, we found that MYH9 is an effective promoter of tumor stemness that facilitates hepatocellular carcinoma pathogenesis. Importantly, targeting MYH9 remarkably improved the survival of hepatocellular carcinoma-bearing mice and promoted sorafenib sensitivity of hepatocellular carcinoma cells in vivo. Mechanistic analysis suggested that MYH9 interacted with GSK3β and reduced its protein expression by ubiquitin-mediated degradation, which therefore dysregulated the β-catenin destruction complex and induced the downstream tumor stemness phenotype, epithelial-mesenchymal transition, and c-Jun signaling in HCC. C-Jun transcriptionally stimulated MYH9 expression and formed an MYH9/GSK3β/β-catenin/c-Jun feedback loop. X protein is a hepatitis B virus (HBV)-encoded key oncogenic protein that promotes HCC pathogenesis. Interestingly, we observed that HBV X protein (HBX) interacted with MYH9 and induced its expression by modulating GSK3β/β-catenin/c-Jun signaling. Targeting MYH9 blocked HBX-induced GSK3β ubiquitination to activate the β-catenin destruction complex and suppressed cancer stemness and EMT. Based on TCGA database analysis, MYH9 was found to be elevated and conferred poor prognosis for hepatocellular carcinoma patients. In clinical samples, high MYH9 expression levels predicted poor prognosis of hepatocellular carcinoma patients. These findings identify the suppression of MYH9 as an alternative approach for the effective eradication of CSC properties to inhibit cancer migration, invasion, growth, and sorafenib resistance in HCC patients. Our study demonstrated that MYH9 is a crucial therapeutic target in HCC.

PTP1B up-regulates EGFR expression by dephosphorylating MYH9 at Y1408 to promote cell migration and invasion in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide. Protein tyrosine phosphatase 1B (PTP1B) is a member of protein tyrosine phosphatases (PTPs) family. In our previous work, PTP1B was found to be overexpressed in ESCC tissues and made contributions to the the cell migration and invasion as well as lung metastasis of ESCC. In this study, we explored the underlying molecular mechanisms. PTP1B enhanced cell migration and invasion by promoting epidermal growth factor receptor (EGFR) expression in ESCC, which was relied on phosphatase activity of PTP1B. Using GST-pulldown combined with LC/MS/MS, we found that nonmuscle myosin IIA (MYH9) was a novel substrate of PTP1B in ESCC cells. PTP1B dephosphorylated MYH9 at Y1408, by which PTP1B up-regulated EGFR expression and enhanced cell migration and invasion in ESCC. In conclusion, our study first reported that PTP1B was the positive regulator of EGFR by dephosphorylating MYH9 at Y1408 to promote cell migration and invasion, which revealed the regulatory mechanism of PTP1B-MYH9-EGFR axis in ESCC.

TGF-β receptor inhibitor LY2109761 enhances the radiosensitivity of gastric cancer by inactivating the TGF-β/SMAD4 signaling pathway

Radiotherapy is used to treat gastric cancer (GC); however, radioresistance challenges the clinical outcomes of GC, and the mechanisms of radioresistance in GC remain poorly understood. Here, we report that the TGF-β receptor inhibitor, LY2109761 (LY), is a potential radiosensitizer both in vitro and in vivo. As per the Cancer Genome Atlas database, TGF-β overexpression is significantly related to poor overall survival in GC patients. We demonstrated that the TGF-β/SMAD4 signaling pathway was activated in both radioresistant GC cells and radioresistant GC patients. As a TGF-β receptor inhibitor, LY can enhance the activities of irradiation by inhibiting cell proliferation, decreasing clonogenicity and increasing apoptosis. Moreover, LY attenuated the radiation-induced migration and invasion, epithelial-mesenchymal transition (EMT), inflammatory factor activation, immunosuppression, and cancer stem cell characteristics of GC cells, thus leading to radiosensitization of the GC cells. We confirmed that LY reduced tumor growth, inhibited TGF-β/SMAD4 pathway activation and reversed irradiation-induced EMT in a tumor xenograft model. Our findings indicate that the novel TGF-β receptor inhibitor, LY, increases GC radiosensitivity by directly regulating the TGF-β/SMAD4 signaling pathway. These findings provide new insight for radiotherapy in GC patients.

Effects of cisatracurium on epithelial-to-mesenchymal transition in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of cancer worldwide, with a poor prognosis. The aim of the present study was to investigate the effect of cisatracurium (Cis) on epithelial-to-mesenchymal transition (EMT) in ESCC and its potential mechanism of action. In the present study, Cis was used to treat ECA-109 cells, with cell proliferation measured by a Cell Counting Kit-8 assay and the expression of TGF-β and phospho-Smad2/3 detected by western blotting. TGF-β was then applied to induce EMT. Flow cytometry, wound healing and Transwell assays were used to evaluate cell proliferation, apoptosis, invasion and migration. In addition, cell cycle-related proteins, including cyclin D1, p53 and p21, and EMT-associated proteins, including E-cadherin (E-cad), N-cadherin (N-cad), Vimentin and Slug, were examined by western blot analysis. The results revealed that Cis inhibited the proliferation and promoted apoptosis of ESCC cells. Following treatment with Cis, the expression of TGF-β and phosphorylation of Smad2/3 were downregulated. Cis also suppressed cancer cell invasion and migration induced by TGF-β. In addition, the expression levels of cyclin D1 were decreased, accompanied by increased p53 and p21 expression. In addition, the expression level of E-cad was increased, whereas N-cad, Vimentin and Slug were significantly reduced. Taken together, the results of the present study revealed that exposure of ESCC cells to Cis inhibited EMT and reduced cell invasion and metastasis through the TGF-β/Smad signaling pathway.

SOX9 promotes epithelial-mesenchymal transition via the Hippo-YAP signaling pathway in gastric carcinoma cells

SRY-box 9 (SOX9) is overexpressed in a number of human tumors, including gastric cancer (GC). However, the function of SOX9 in the development of GC remains unknown. In the present study, SOX9 activated the Hippo-yes-associated protein (YAP) signaling pathway to enhance the epithelial-mesenchymal transition in GC cell lines. The results suggested that SOX9 knockdown inhibited invasion, proliferation and migration of GC cells. Furthermore, SOX9 silencing upregulated the expression of E-cadherin, an epithelial marker, and downregulated the expression of mesenchymal markers, including snail family transcriptional repressor 1, vimentin and N-cadherin. SOX9 overexpression increased the expression of the aforementioned markers. SOX9 significantly affected YAP phosphorylation and total YAP protein levels, suggesting that SOX9 is involved in the Hippo-YAP signaling pathway. The current study revealed that SOX9 may be involved in the pathogenesis of GC, and further elucidation of the pathways involved may support the development of novel therapeutic options for the treatment of GC.