Heterogeneity and plasticity of epithelial-mesenchymal transition (EMT) in cancer metastasis: Focusing on partial EMT and regulatory mechanisms

Decoding the tumour-modulatory roles of LIMK2

LIM domains kinase 2 (LIMK2) is a 72 kDa protein that regulates actin and cytoskeleton reorganization. Once phosphorylated by its upstream activator (ROCK1), LIMK2 can phosphorylate cofilin to inactivate it. This relieves the levering stress on actin and allows polymerization to occur. Actin rearrangement is essential in regulating cell cycle progression, apoptosis, and migration. Dysregulation of the ROCK1/LIMK2/cofilin pathway has been reported to link to the development of various solid cancers such as breast, lung, and prostate cancer and liquid cancer like leukemia. This review aims to assess the findings from multiple reported in vitro, in vivo, and clinical studies on the potential tumour-regulatory role of LIMK2 in different human cancers. The findings of the selected literature unraveled that activated AKT, EGF, and TGF-β pathways can upregulate the activities of the ROCK1/LIMK2/cofilin pathway. Besides cofilin, LIMK2 can modulate the cellular levels of other proteins, such as TPPP1, to promote microtubule polymerization. The tumour suppressor protein p53 can transactivate LIMK2b, a splice variant of LIMK2, to induce cell cycle arrest and allow DNA repair to occur before the cell enters the next phase of the cell cycle. Additionally, several non-coding RNAs, such as miR-135a and miR-939-5p, could also epigenetically regulate the expression of LIMK2. Since the expression of LIMK2 is dysregulated in several human cancers, measuring the tissue expression of LIMK2 could potentially help diagnose cancer and predict patient prognosis. As LIMK2 could play tumour-promoting and tumour-inhibiting roles in cancer development, more investigation should be conducted to carefully evaluate whether introducing a LIMK2 inhibitor in cancer patients could slow cancer progression without posing clinical harms.

A new high-throughput screening methodology for the discovery of cancer-testis antigen using multi-omics data

BACKGROUND

Cancer/testis antigens (CTAs), also known as tumor-specific antigens (TSAs) are specifically expressed in cancer cells and exhibit high immunogenicity, making them promising targets for immunotherapy and cancer vaccines.

METHODS

A new integrated high-throughput screening methodology for CTAs was proposed in this study through combining DNA methylation and RNA sequencing data. Briefly, the genes with increased transcript level and decreased DNA methylation were identified by multi-omics analysis. RNA sequencing studies in cell lines exposed to DNA methyltransferase (DNMT) inhibitors were performed to validate the inherent causal relationship between DNA hypomethylation and gene expression upregulation.

RESULTS

We proposed a new integrated high-throughput screening methodology for identification of CTAs using multi-omics analysis. In addition, we tested the feasibility of this method using gastric cancer (GC) as an example. In GC, we identified over 2000 primary candidate CTAs and ultimately identified 20 CTAs with significant tissue-specificity, including a testis-specific serine protease TESSP1/PRSS41. Integrated analysis confirmed that PRSS41 expression was reactivated in gastrointestinal cancers by promoter DNA hypomethylation at the CpG site (cg08104780). Additionally, DNA hypomethylation of PRSS41 predicted a poor prognosis in GC.

CONCLUSION

We propose a new high-throughput screening method for the identification of CTAs in cancer and validate its effectiveness. Our work emphasizes that serine protease PRSS41 is a novel TSA that is reactivated in GC due to promoter DNA hypomethylation.

A novel TGFbeta/TGILR axis mediates crosstalk between cancer-associated fibroblasts and tumor cells to drive gastric cancer progression

Transforming growth factor beta (TGFβ) signaling plays a critical role in tumorigenesis and metastasis. However, little is known about the biological function of TGFbeta-induced lncRNA in cancer. In this study, we discovered a novel TGFbeta-induced lncRNA, termed TGILR, whose function in cancer remains unknown to date. TGILR expression was directly activated by the canonical TGFbeta/SMAD3 signaling axis, and this activation is highly conserved in cancer. Clinical analysis showed that TGILR overexpression showed a significant correlation with lymph node metastasis and poor survival and was an independent prognostic factor in gastric cancer (GC). Depletion of TGILR caused an obvious inhibitory effect on GC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) in vitro and in vivo. More importantly, we demonstrated that TGFbeta signaling in GC was overactivated due to cancer-associated fibroblast (CAF) infiltration. Mechanistically, increased level of CAF-secreted TGFbeta activates TGFbeta signaling, leading to TGILR overexpression in GC cells. Meanwhile, TGILR overexpression inhibited the microRNA biogenesis of miR-1306 and miR-33a by interacting with TARBP2 and reducing its protein stability, thereby promoting GC progression via TCF4-mediated EMT signaling. In conclusion, CAF infiltration drives GC metastasis and EMT signaling through activating TGFbeta/TGILR axis. Targeted blocking of CAF-derived TGFbeta should be a promising anticancer strategy in GC.

P53/NANOG balance; the leading switch between poorly to well differentiated status in liver cancer cells

Enforcing a well-differentiated state on cells requires tumor suppressor p53 activation as a key player in apoptosis induction and well differentiation. In addition, recent investigations showed a significant correlation between poorly differentiated status and higher expression of NANOG. Inducing the expression of NANOG and decreasing p53 level switch the status of liver cancer cells from well differentiated to poorly status. In this review, we highlighted p53 and NANOG cross-talk in hepatocellular carcinoma (HCC) which is regulated through mitophagy and makes it a novel molecular target to attenuate cancerous phenotype in the management of this tumor.

Epithelial-to-mesenchymal transition and NF-kB pathways are promoted by a mutant form of DDB2, unable to bind PCNA, in UV-damaged human cells

BACKGROUND

DNA-Damaged Binding protein 2 (DDB2) is a protein involved in the early step of Nucleotide Excision Repair. Recently, it has been reported that DDB2 is involved in epithelial-to-mesenchymal transition (EMT), key process in tumour invasiveness and metastasis formation. However, its role is not completely known.

METHODS

Boyden chamber and cell adhesion assays, and ICELLigence analysis were performed to detect HEK293 adhesion and invasion. Western blotting and gelatine zymography techniques were employed to assess the EMT protein levels and MMP enzymatic activity. Immunofluorescence analysis and pull-down assays facilitated the detection of NF-kB sub-cellular localization and interaction.

RESULTS

We have previously demonstrated that the loss of DDB2-PCNA binding favours genome instability, and increases cell proliferation and motility. Here, we have investigated the phenotypic and molecular EMT-like changes after UV DNA damage, in HEK293 clones stably expressing DDB2Wt protein or a mutant form unable to interact with PCNA (DDB2PCNA-), as well as in HeLa cells transiently expressing the same DDB2 constructs. Cells expressing DDB2PCNA- showed morphological modifications along with a reduced expression of E-cadherin, an increased activity of MMP-9 and an improved ability to migrate, in concomitance with a significant upregulation of EMT-associated Transcription Factors (TFs), whose expression has been reported to favour tumour invasion. We observed a higher expression of c-Myc oncogene, NF-kB, both regulating cell proliferation and metastatic process, as well as ZEB1, a TF significantly associated with tumorigenic potential and cell migratory ability. Interestingly, a novel interaction of DDB2 with NF-kB was detected and found to be increased in cells expressing the DDB2PCNA-, suggesting a direct modulation of NF-kB by DDB2.

CONCLUSION

These results highlight the role of DDB2-PCNA interaction in counteracting EMT since DDB2PCNA- protein induces in HEK293 transformed cells a gain of function contributing to the acquisition of a more aggressive phenotype.

N-cadherin: A diagnostic marker to help discriminate primary liver carcinomas from extrahepatic carcinomas

Distinguishing primary liver cancer (PLC), namely hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), from liver metastases is of crucial clinical importance. Histopathology remains the gold standard, but differential diagnosis may be challenging. While absent in most epithelial, the expression of the adherens junction glycoprotein N-cadherin is commonly restricted to neural and mesenchymal cells, or carcinoma cells that undergo the phenomenon of epithelial-to-mesenchymal transition (EMT). However, we recently established N- and E-cadherin expression as hallmarks of normal hepatocytes and cholangiocytes, which are also preserved in HCC and iCCA. Therefore, we hypothesized that E- and/or N-cadherin may distinguish between carcinoma derived from the liver vs carcinoma of other origins. We comprehensively evaluated E- and N-cadherin in 3359 different tumors in a multicenter study using immunohistochemistry and compared our results with previously published 882 cases of PLC, including 570 HCC and 312 iCCA. Most carcinomas showed strong positivity for E-cadherin. Strong N-cadherin positivity was present in HCC and iCCA. However, except for clear cell renal cell carcinoma (23.6% of cases) and thyroid cancer (29.2%), N-cadherin was only in some instances faintly expressed in adenocarcinomas of the gastrointestinal tract (0%-0.5%), lung (7.1%), pancreas (3.9%), gynecological organs (0%-7.4%), breast (2.2%) as well as in urothelial (9.4%) and squamous cell carcinoma (0%-5.6%). As expected, N-cadherin was detected in neuroendocrine tumors (25%-75%), malignant melanoma (46.2%) and malignant mesothelioma (41%). In conclusion, N-cadherin is a useful marker for the distinction of PLC vs liver metastases of extrahepatic carcinomas (P < .01).

New roles of tumor-derived exosomes in tumor microenvironment

Throughout tumorigenesis, the co-evolution of tumor cells and their surrounding microenvironment leads to the development of malignant phenotypes. Cellular communication within the tumor microenvironment (TME) plays a critical role in influencing various aspects of tumor progression, including invasion and metastasis. The release of exosomes, a type of extracellular vesicle, by most cell types in the body, is an essential mediator of intercellular communication. A growing body of research indicates that tumor-derived exosomes (TDEs) significantly expedite tumor progression through multiple mechanisms, inducing epithelial-mesenchymal transition and macrophage polarization, enhancing angiogenesis, and aiding in the immune evasion of tumor cells. Herein, we describe the formation and characteristics of the TME, and summarize the contents of TDEs and their diverse functions in modulating tumor development. Furthermore, we explore potential applications of TDEs in tumor diagnosis and treatment.

Cancer-associated fibroblasts promote gastric cancer cell proliferation by paracrine FGF2-driven ribosome biogenesis

The cancer-associated fibroblast (CAF)-derived secretome plays critical roles in tumor progression by remodelling tumor microenvironment. Tumorigenesis is accompanied by the transformation of normal fibroblasts (NF) into CAF, leading to significant changes in their secretome. This work aims to identify the differential components of secretome between NFs and CAFs and reveal their functions in gastric cancer (GC). Firstly, our molecular typing studies and immune infiltration analysis showed that CAF infiltration level was increased and showed a significant association with clinical characteristics and poor prognosis of GC patients. Secondly, RNA-seq analysis revealed that a total of 1531 genes showed significant expression changes between NF and CAF. According to the annotation of the Human Protein Atlas (HPA) database, 147 genes encode secreted proteins, including FGF2. Particularly, the cell co-culture and RNA sequencing studies confirmed that exogenous recombinant FGF2 protein treatment promoted GC cell proliferation by enhancing ribosome biogenesis. The rescue assay showed that CAF-secreted FGF2 protein promotes GC cell growth and proliferation in a FGFR1-dependent manner. Our finding provides evidence that targeting blockade of CAF-derived FGF2 protein might be a promising treatment for GC.

FTO promotes gastric cancer progression by modulating MAP4K4 expression via demethylation in an m6A-dependent manner

Gastric cancer (GC) is a serious malignant tumour with a high mortality rate and a poor prognosis. Recently, emerging evidence has suggested that N6-methyladenosine (m6A) modification plays a crucial regulatory role in cancer progression. However, the exact role of m6A regulatory factors FTO in GC is unclear. First, the expression of m6A methylation-related regulatory factors in clinical samples and the clinical data of the corresponding patients were obtained from The Cancer Genome Atlas (TCGA-STAD) dataset, and correlation analysis between FTO expression and patient clinicopathological parameters was subsequently performed. qRT-PCR, immunohistochemistry (IHC) and western blotting (WB) were used to verify FTO expression in GC. CCK-8, EdU, flow cytometry and transwell assays were used to evaluate the effect of FTO on the behaviour of GC cells. Transcriptome sequencing and RNA immunoprecipitation analysis were used to explore the potential regulatory mechanisms mediated by FTO. FTO was highly expressed in GC tissues and cells, and high expression of FTO predicted a worse prognosis than low expression. Functionally, overexpression of FTO promoted the proliferation, migration and invasion of GC cells but inhibited cell apoptosis. Mechanistically, we found that FTO is upregulated in GC and promotes GC progression by modulating the expression of MAP4K4. Taken together, our findings provide new insights into the effects of FTO-mediated m6A demethylation and could lead to the development of new strategies for GC monitoring and aggressive treatment.

Linking EMT Status of Circulating Tumor Cells to Clinical Outcomes in Lung Cancer

Background

Lung cancer (LC) remains a leading cause of cancer-related mortality worldwide, with its prognosis influenced by complex biological factors.

Objective

This study delves into the clinical relevance of circulating tumor cells (CTCs) and their Epithelial-Mesenchymal Transition (EMT) status in LC patients.

Methods

We enrolled 30 newly diagnosed LC patients and utilized the CanPatrol technique for the separation and categorization of CTCs from peripheral blood samples. Immunofluorescent staining identified epithelial (CK8/18/19, EpCAM), mesenchymal (Vimentin, Twist), and leukocyte (CD45) markers in these cells. Fluorescence microscopy analyzed the slides, and RECIST 1.1 criteria assessed treatment response. Spearman's method was used to correlate CTCs' EMT states with their count and clinical characteristics.

Results

Our findings reveal three distinct CTC groups: epithelial (E-CTCs), hybrid epithelial/mesenchymal (E/M-CTCs), and mesenchymal (M-CTCs). Significant statistical differences were observed in stages III-IV vs I-II, tumor sizes T3-T4 vs T1-T2, and in the presence or absence of distant metastasis and lymph node involvement. Notably, the count of E/M-CTCs was positively correlated with TNM staging, tumor size, lymph node, and distant metastasis. Changes in M-CTC count pre- and post-treatment closely mirrored disease progression and control, showing considerable consistency with RECIST criteria.

Conclusion

In conclusion, the EMT status of CTCs, especially E/M-CTCs, holds predictive value for LC staging, tumor size, and metastasis. Dynamic monitoring of M-CTCs can accurately reflect disease progression.

Expression Profiling of EMT Transcriptional Regulators ZEB1 and ZEB2 in Different Histopathological Grades of Oral Squamous Cell Carcinoma Patients

Background

Pakistan has a high burden of oral cancers, with a prevalence rate of around 9%. Oral Squamous Cell Carcinoma (OSCC) accounts for about 90% of oral cancer cases. Epithelial to Mesenchymal Transition (EMT) gets highly stimulated in tumor cells by adopting subsequent malignant features of highly invasive cancer populations. Zinc Finger E-Box binding factors, ZEB1 and ZEB2, are regulatory proteins that promote EMT by suppressing the adherent ability of cells transforming into highly motile cancerous cells. The present study aimed to analyze the expression of EMT regulators, ZEB1 and ZEB2, and their association with the clinicopathological features in different grades of OSCC patients.

Methods

Tissue samples were collected for both case and control groups from the recruited study participants. Cancer tissues (cases) were collected from the confirmed OSCC patients, and healthy tissues (controls) were collected from third-molar dental extraction patients. The study participants were recruited with informed consent and brief demographic and clinical characteristics. The case group was further segregated with respect to the histological cancer grading system into well-differentiated (WD), moderately differentiated (MD), and poorly differentiated (PD) squamous cell carcinoma (SCC) groups. RNA was extracted from the tissue samples for expression profiling of ZEB1 and ZEB2 genes through quantitative real-time PCR (qRT-PCR).

Results

All of the recruited participants had a mean age of 46.55 ± 11.7 (years), with most of them belonging to Urdu speaking ethnic group and were married. The BMI (kg/m2) of the healthy participants was in the normal range (18-22 kg/m2). However, BMI was found to be reduced with the proliferation in the pathological state of cancer. The oral hygiene of patients was better than the healthy participants, possibly due to the strict oral hygiene practice concerns of consultants. Every recruited OSCC patient had one or multiple addiction habits for more than a year. Patients reported health frailty (46.6%), unhealed mouth sores (40%), swallowing difficulties and white/reddish marks (80%), and restricted mouth opening (64.4%). Furthermore, 82.2% of the recruited patients observed symptoms within 1-12 months, and buccal mucosa was the most exposed tumor site among 55.6% of the patients. Expression profiling of EMT regulators showed gradual over-expressions of ZEB1 (8, 20, and 42 folds) and ZEB2 (4, 10, and 18 folds) in respective histological cancer grades.

Conclusion

High expressions of ZEBs have been significantly associated with cancer progression and poor health. However, no association was found between OSCC with other clinicopathological features when compared to healthy controls.

Gastric cancer with brain metastasis: from molecular characteristics and treatment

Gastric cancer is one of the cancers with increasing incidence and ranks fourth globally among the most frequent causes of cancer-related mortality. Early gastric cancer is often asymptomatic or presents with atypical symptoms, and the majority of patients present with advanced disease upon diagnosis. Brain metastases are present in approximately 1% of gastric cancer patients at the time of diagnosis, which significantly contributed to the overall mortality of the disease worldwide. Conventional therapies for patients with brain metastases remain limited and the median overall survival of patients is only 8 months in advanced cases. Recent studies have improved our understanding of the molecular mechanisms underlying gastric cancer brain metastases, and immunotherapy has become an important treatment option in combination with radiotherapy, chemotherapy, targeted therapy and surgery. This review aims to provide insight into the cellular processes involved in gastric cancer brain metastases, discuss diagnostic approaches, evaluate the integration of immune checkpoint inhibitors into treatment and prognosis, and explore the predictive value of biomarkers in immunotherapy.

Cancer associated fibroblasts-derived SULF1 promotes gastric cancer metastasis and CDDP resistance through the TGFBR3-mediated TGF-β signaling pathway

SULF1 has been implicated in a number of malignancies. The function of SULF1 in gastric cancer is disputed. The objective of this study was to examine the role and underlying molecular mechanisms of SULF1 in the context of gastric cancer. We found that the expression of SULF1 was increased in gastric cancer, especially in cancer-associated fibroblasts. The overexpression of SULF1 was found to be significantly correlated with unfavorable prognosis among individuals diagnosed with gastric cancer. Functionally, cancer-associated fibroblasts-derived SULF1 served as a oncogenic molecule which facilitated gastric cancer cells metastasis and CDDP resistance. Mechanistically, SULF1 regulated the communication between gastric cancer cells and cancer-associated fibroblasts in tumor microenvironment as a signaling molecule. Cancer-associated fibroblasts-secreted SULF1 interfered with the interaction between TGF-β1 and TGFBR3 by combining with TGFBR3 on gastric cancer cell membrane, subsequently activated TGF-β signaling pathway. In conclusion, our findings have presented novel approaches for potential treatment and prognosis prediction in individuals diagnosed with gastric cancer through the targeting of the CAFs-SULF1-TGFBR3-TGF-β1 signaling axis.

6-O-endosulfatases in tumor metastasis: heparan sulfate proteoglycans modification and potential therapeutic targets

Metastasis is the leading cause of cancer-associated mortality. Although advances in the targeted treatment and immunotherapy have improved the management of some cancers, the prognosis of metastatic cancers remains unsatisfied. Therefore, the specific mechanisms in tumor metastasis need further investigation. 6-O-endosulfatases (SULFs), comprising sulfatase1 (SULF1) and sulfatase 2 (SULF2), play pivotal roles in the post-synthetic modifications of heparan sulfate proteoglycans (HSPGs). Consequently, these extracellular enzymes can regulate a variety of downstream pathways by modulating HSPGs function. During the past decades, researchers have detected the expression of SULF1 and SULF2 in most cancers and revealed their roles in tumor progression and metastasis. Herein we reviewed the metastasis steps which SULFs participated in, elucidated the specific roles and mechanisms of SULFs in metastasis process, and discussed the effects of SULFs in different types of cancers. Moreover, we summarized the role of targeting SULFs in combination therapy to treat metastatic cancers, which provided some novel strategies for cancer therapy.

OVOL2 induces autophagy-mediated epithelial-mesenchymal transition by the ERK1/2 MAPK signaling in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is one of the leading causes of cancer-related death worldwide. Epithelial-mesenchymal transition (EMT) plays an important role in malignant tumor progression. Recently, accumulating evidence has shown that autophagy is involved in the regulation of EMT-induced migration. Therefore, the exploration of targets to inhibit EMT by targeting autophagy is important. In this study, we found that OVO-like zinc finger 2 (OVOL2) may be a key target for regulating autophagy-induced EMT. Firstly, we found that OVOL2 expression was dramatically downregulated in LUAD. Low expression of OVOL2 is an indicator of poor prognosis in LUAD. In vitro experiments have shown that downregulation of OVOL2 expression induces EMT, thereby promoting malignant biological behavior, such as proliferation, migration, and invasion of LUAD cells. Interestingly, autophagy is a key step in regulating OVOL2 and inducing EMT. Furthermore, OVOL2 regulates autophagy through the MAPK signaling pathway, ultimately inhibiting the malignant progression of LUAD.

Unveiling the mechanisms and challenges of cancer drug resistance

Cancer treatment faces many hurdles and resistance is one among them. Anti-cancer treatment strategies are evolving due to innate and acquired resistance capacity, governed by genetic, epigenetic, proteomic, metabolic, or microenvironmental cues that ultimately enable selected cancer cells to survive and progress under unfavorable conditions. Although the mechanism of drug resistance is being widely studied to generate new target-based drugs with better potency than existing ones. However, due to the broader flexibility in acquired drug resistance, advanced therapeutic options with better efficacy need to be explored. Combination therapy is an alternative with a better success rate though the risk of amplified side effects is commonplace. Moreover, recent groundbreaking precision immune therapy is one of the ways to overcome drug resistance and has revolutionized anticancer therapy to a greater extent with the only limitation of being individual-specific and needs further attention. This review will focus on the challenges and strategies opted by cancer cells to withstand the current therapies at the molecular level and also highlights the emerging therapeutic options -like immunological, and stem cell-based options that may prove to have better potential to challenge the existing problem of therapy resistance. Video Abstract.

Pirfenidone inhibits TGF-β1-induced metabolic reprogramming during epithelial-mesenchymal transition in non-small cell lung cancer

Metastasis is an important contributor to increased mortality rates in non-small cell lung cancer (NSCLC). The TGF-β signalling pathway plays a crucial role in facilitating tumour metastasis through epithelial-mesenchymal transition (EMT). Glycolysis, a key metabolic process, is strongly correlated with NSCLC metastasis. Pirfenidone (PFD) has been shown to safely and effectively inhibit TGF-β1 in patients with lung diseases. Furthermore, TGF-β1 and glycolysis demonstrate an interdependent relationship within the tumour microenvironment. Our previous study demonstrated that PFD effectively inhibited glycolysis in NSCLC cells, prompting further investigation into its potential antitumour effects in this context. Therefore, the present study aims to investigate the potential antitumour effect of PFD in NSCLC and explore the relationship among TGF-β1, glycolysis and EMT through further experimentation. The antitumour effects of PFD were evaluated using five different NSCLC cell lines and a xenograft tumour model. Notably, PFD demonstrated a significant antitumour effect specifically in highly glycolytic H1299 cells. To elucidate the underlying mechanism, we compared the efficacy of PFD after pretreatment with either TGF-β1 or a TGF-β receptor inhibitor (LY2109761). The energy metabolomics analysis of tumour tissue demonstrated that PFD, a chemosensitizing agent, reduced lactate and ATP production, thereby inhibiting glycolysis and exerting synergistic antineoplastic effects. Additionally, PFD combined with cisplatin targeted TGF-β1 to inhibit glycolysis during EMT and enhanced the chemosensitization of A549 and H1299 cells. The magnitude of the anticancer effect exhibited by PFD was intricately linked to its metabolic properties.

Promoting effect and immunologic role of secretogranin II on bladder cancer progression via regulating MAPK and NF-κB pathways

Bladder cancer (BLCA) is ranked among the top ten most prevalent cancers worldwide and is the second most common malignant tumor within the field of urology. The limited effectiveness of immune targeted therapy in treating BLCA, due to its high metastasis and recurrence rates, necessitates the identification of new therapeutic targets. Secretogranin II (SCG2), a member of the chromaffin granin/secreted granin family, plays a crucial role in the regulated release of peptides and hormones. The role of SCG2 in the tumor microenvironment (TME) of lung adenocarcinoma and colon cancer has been established, but its functional significance in BLCA remains uncertain. This study aimed to investigate SCG2 expression in 15 bladder cancer tissue samples and their corresponding adjacent control tissues. The potential involvement of SCG2 in BLCA progression was assessed using various techniques, including analysis of public databases, immunohistochemistry, Western Blotting, immunofluorescence, wound-healing assay, Transwell assay, and xenograft tumor formation experiments in nude mice. This study provided novel evidence indicating that SCG2 plays a pivotal role in facilitating the proliferation, migration, and invasion of BLCA by activating the MEK/Erk and MEK/IKK/NF-κB signaling pathways, as well as by promoting M2 macrophage polarization. These findings propose the potential of SCG2 as a molecular target for immunotherapy in human BLCA.

The biological role of extracellular vesicles in gastric cancer metastasis

Gastric cancer (GC) is a tumor characterized by high incidence and mortality, with metastasis being the primary cause of poor prognosis. Extracellular vesicles (EVs) are an important intercellular communication medium. They contain bioactive substances such as proteins, nucleic acids, and lipids. EVs play a crucial biological role in the process of GC metastasis. Through mechanisms such as remodeling the tumor microenvironment (TME), immune suppression, promoting angiogenesis, and facilitating epithelial-mesenchymal transition (EMT) and mesothelial-mesenchymal transition (MMT), EVs promote invasion and metastasis in GC. Further exploration of the biological roles of EVs will contribute to our understanding of the mechanisms underlying GC metastasis and may provide novel targets and strategies for the diagnosis and treatment of GC. In this review, we summarize the mechanisms by which EVs influence GC metastasis from four aspects: remodeling the TME, modulating the immune system, influencing angiogenesis, and modulating the processes of EMT and MMT. Finally, we briefly summarized the organotropism of GC metastasis as well as the potential and limitations of EVs in GC.

System Biology Approach in Investigating Epithelial-Mesenchymal Transition (EMT)

Epithelial-mesenchymal transition (EMT) is a trans-differentiating and reversible process that leads to dramatic cell phenotypic changes, enabling epithelial cells in acquiring mesenchymal phenotypes and behaviors. EMT plays a crucial role during embryogenesis, and occurs in several para-physiologic and pathological conditions, as during fibrosis or cancer development. EMT displays some hallmarks of critical transitions, as a sudden change in the overall configuration of a system in correspondence of specific tipping point around which a "catastrophic bifurcation" happens. The transition occurs when external conditions breach specific thresholds. This definition helps in highlighting two main aspects: (1) the change involves the overall system, rather than single, discrete components; (2) cues from the microenvironment play an irreplaceable role in triggering the transition. This evidence implies that critical transition should be ascertained focusing the investigation at the system level (rather than investigating only molecular parameters) in a well-defined context, as the transition is strictly dependent on the microenvironment in which it occurs. Therefore, we need a systems biology approach to investigate EMT across the Waddington-like epigenetic landscape wherein the participation of both internal and external cues can be studied to follow the extent and the main characteristics of the phenotypic transition. Herein, we suggest a set of systems parameters (motility, invasiveness) altogether with specific molecular/histological markers to identify those critical observables, which can be integrated into a comprehensive mechanistic model.

Prostate cancer-derived small extracellular vesicle proteins: the hope in diagnosis, prognosis, and therapeutics

Current diagnostic tools for prostate cancer (PCa) diagnosis and risk stratification are insufficient. The hidden onset and poor efficacy of traditional therapies against metastatic PCa make this disease a heavy burden in global men's health. Prostate cancer-derived extracellular vesicles (PCDEVs) have garnered attention in recent years due to their important role in communications in tumor microenvironment. Recent advancements have demonstrated PCDEVs proteins play an important role in PCa invasion, progression, metastasis, therapeutic resistance, and immune escape. In this review, we briefly discuss the applications of sEV proteins in PCa diagnosis and prognosis in liquid biopsy, focus on the roles of the PCa-derived small EVs (sEVs) proteins in tumor microenvironment associated with cancer progression, and explore the therapeutic potential of sEV proteins applied for future metastatic PCa therapy.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Integrating network pharmacology with molecular docking for elucidation of molecular biological mechanisms of Jiedu Qingjin formula for non-small cell lung cancer

Traditional Chinese medicine is an important part of complementary alternative medicine. Jiedu Qingjin formula (JDQJF) is an effective national invention patent for the treatment of non-small cell lung cancer (NSCLC). We investigated the molecular biological mechanisms based on network pharmacology, molecular docking, and molecular dynamics simulations. Compounds of JDQJF were screened through the TCMSP, ETCM, and literature. Targets were searched by DrugBank and predicted by SwissTargetPrediction. GEO database was applied for screening differentially expressed genes between cancerous tissues and healthy tissues of NSCLC. Subsequently, the protein-protein interaction between JDQJF and NSCLC were obtained by Cytoscape. Visual analyses were carried out to extract candidate genes, then subjected to Metascape for enrichment analyses. Finally, molecular docking was performed by AutoDock, and the best complexes were subjected to molecular dynamics simulation and binding energy calculations by MMPBSA. A total of 273 compounds, 390 targets, 3146 GO terms, and 174 KEGG pathways were obtained. Five potential compounds (quercetin, adenosine, apigenin, heptadecanoic acid, and luteolin) were notably modulated by key targets AKT1, MAPK3, and RAF1. Enrichment results included cell cycle process, growth transduction factor, immune response-activating transduction, and involved PI3K/AKT, MAPK, NF-κB and VEGF pathway. RAF1-quercetin showed the highest binding affinity (-9.1 kcal/mol), revealed stable interactions during the simulation, and the highest estimated relative binding energy of the RAF1-Heptadecanoic was -184.277 kcal/mol. This study suggested that EMT-related, inflammation-related, immune-related, and angiogenesis-related pathways may be associated with JDQJF, and involved in the advancement of NSCLC, which points out the research direction for subsequent utility mechanism validation.Communicated by Ramaswamy H. Sarma.

LncRNA THUMPD3-AS1 promotes invasion and EMT in gastric cancer by regulating the miR-1297/BCAT1 pathway

Long noncoding RNA (lncRNA) plays crucial roles in the development of gastric cancer (GC); however, studies of their mechanisms of action are needed to determine their clinical value. The aim of this study is to explore the effects and mechanisms of THUMPD3-AS1 in GC. Elevated levels of THUMPD3-AS1 were observed in GC and demonstrated a significant positive correlation with poor prognosis. Functionally, THUMPD3-AS1 promoted GC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) and induced tumor growth in vivo. THUMPD3-AS1 exerts its regulatory function on BCAT1 through competitive binding with miR-1297. Further investigations confirmed that both THUMPD3-AS1 and miR-1297 interact with BCAT1. These findings suggest that THUMPD3-AS1 promotes GC invasion and EMT by regulating the miR-1297/BCAT1 pathway, indicating that THUMPD3-AS1 may serve as a biomarker and therapeutic target for GC.

Tumor-derived CircRNA_102191 promotes gastric cancer and facilitates M2 macrophage polarization

BACKGROUND

Gastric cancer is a common malignant tumor of the digestive tract and the fourth leading cause of death from cancer-related diseases. In recent years, many studies have found that circular RNAs play an important role in cancer. Tumor-associated macrophages (TAMs) are also critical for tumor progression.

OBJECTIVE

This study examined the role of circRNA_102191 in gastric cancer progression.

METHODS

The relative mRNA levels were determined by qRT-PCR. Western blotting and ELISA were used to detect the protein levels. In vitro proliferation was assessed using CCK8 and clonogenic assays. The migration and invasion of cell lines were assessed by transwell-based assays. The interactions between molecules were detected using a luciferase reporter assay. M0 macrophages were induced with PMA. M1 macrophages were induced with LPS and IFN-γ, and M2 macrophages were induced with IL-4.

RESULTS

The expression of circRNA_102191 was enhanced significantly in gastric cancer cell lines and clinical tumor tissues. CircRNA_102191 promotes gastric cancer cell progression by regulating miR-493-3p and its downstream target gene XPR1. CircRNA_102191 can enhance the EMT process of gastric cancer cells by promoting the M2 polarization of macrophages.

CONCLUSION

CircRNA_102191 promotes the biological function of gastric cancer cells by regulating the miR-493-3p/XPR1 axis and M2 macrophage polarization.

Serine protease PRSS56, a novel cancer-testis antigen activated by DNA hypomethylation, promotes colorectal and gastric cancer progression via PI3K/AKT axis

BACKGROUND

Cancer/testis (CT) antigens/genes are usually overexpressed in cancers and exhibit high immunogenicity, making them promising targets for immunotherapy and cancer vaccines. The role of serine protease PRSS56 in cancers remains unknown to date.

METHODS

RNA sequencing studies were performed to screen CT genes in gastric cancer (GC) and colorectal cancer (CRC) cells exposed to DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-AZA-CdR). Bioinformatics analysis was conducted to analyze the correlation between PRSS56 expression and DNA methylation. Functional experiments were performed to explore the biological function of PRSS56 in GC and CRC.

RESULTS

In this study, we identified the testis-specific serine proteases PRSS56 as a novel CT antigen. PRSS56 was frequently overexpressed in various cancers, especially in gastrointestinal cancer. PRSS56 expression was negatively associated with promoter DNA methylation level, and positively associated with gene body methylation level. PRSS56 expression was significantly activated in colorectal and gastric cancer cells exposed to DNA methyltransferase inhibitors. Importantly, our finding highlights that the decreased methylation level of the CpG site cg10242318 in the PRSS56 promoter region resulted in its overexpression in GC and CRC. Additionally, functional assays verified that PRSS56 overexpression activated PI3K-AKT signaling in GC and CRC.

CONCLUSION

Serine protease PRSS56 is a novel CT antigen that is reactivated in cancers by promoter DNA hypomethylation. PRSS56 functions oncogenic roles in GC and CRC by activating of PI3K/AKT axis. Our results presented here represent the first data on the function of the serine protease PRSS56 in cancers.

Emerging role of RNA acetylation modification ac4C in diseases: Current advances and future challenges

The oldest known highly conserved modification of RNA, N4-acetylcytidine, is widely distributed from archaea to eukaryotes and acts as a posttranscriptional chemical modification of RNA, contributing to the correct reading of specific nucleotide sequences during translation, stabilising mRNA and improving transcription efficiency. Yeast Kre33 and human NAT10, the only known authors of ac4C, modify tRNA with the help of the Tan1/THUMPD1 adapter to stabilise its structure. Currently, the mRNA for N4-acetylcytidine (ac4C), catalysed by NAT10 (N-acetyltransferase 10), has been implicated in a variety of human diseases, particularly cancer. This article reviews advances in the study of ac4C modification of RNA and the ac4C-related gene NAT10 in normal physiological cell development, cancer, premature disease and viral infection and discusses its therapeutic promise and future research challenges.

Myeloid-like tumor hybrid cells in bone marrow promote progression of prostate cancer bone metastasis

BACKGROUND

Bone metastasis is the leading cause of death in patients with prostate cancer (PCa) and currently has no effective treatment. Disseminated tumor cells in bone marrow often obtain new characteristics to cause therapy resistance and tumor recurrence. Thus, understanding the status of disseminated prostate cancer cells in bone marrow is crucial for developing a new treatment.

METHODS

We analyzed the transcriptome of disseminated tumor cells from a single cell RNA-sequencing data of PCa bone metastases. We built a bone metastasis model through caudal artery injection of tumor cells, and sorted the tumor hybrid cells by flow cytometry. We performed multi-omics analysis, including transcriptomic, proteomic and phosphoproteomic analysis, to compare the difference between the tumor hybrid cells and parental cells. In vivo experiments were performed to analyze the tumor growth rate, metastatic and tumorigenic potential, drug and radiation sensitivity in hybrid cells. Single cell RNA-sequencing and CyTOF were performed to analyze the impact of hybrid cells on tumor microenvironment.

RESULTS

Here, we identified a unique cluster of cancer cells in PCa bone metastases, which expressed myeloid cell markers and showed a significant change in pathways related to immune regulation and tumor progression. We found that cell fusion between disseminated tumor cells and bone marrow cells can be source of these myeloid-like tumor cells. Multi-omics showed the pathways related to cell adhesion and proliferation, such as focal adhesion, tight junction, DNA replication, and cell cycle, were most significantly changed in these hybrid cells. In vivo experiment showed hybrid cells had a significantly increased proliferative rate, and metastatic potential. Single cell RNA-sequencing and CyTOF showed tumor-associated neutrophils/monocytes/macrophages were highly enriched in hybrid cells-induced tumor microenvironment with a higher immunosuppressive capacity. Otherwise, the hybrid cells showed an enhanced EMT phenotype with higher tumorigenicity, and were resistant to docetaxel and ferroptosis, but sensitive to radiotherapy.

CONCLUSION

Taken together, our data demonstrate that spontaneous cell fusion in bone marrow can generate myeloid-like tumor hybrid cells that promote the progression of bone metastasis, and these unique population of disseminated tumor cells can provide a potential therapeutic target for PCa bone metastasis.