Clinical value of peripheral blood microRNA detection in evaluation of SOX regimen as neoadjuvant chemotherapy for gastric cancer

Intelligent identification system of gastric stromal tumors based on blood biopsy indicators

BACKGROUND

The most prevalent mesenchymal-derived gastrointestinal cancers are gastric stromal tumors (GSTs), which have the highest incidence (60-70%) of all gastrointestinal stromal tumors (GISTs). However, simple and effective diagnostic and screening methods for GST remain a great challenge at home and abroad. This study aimed to build a GST early warning system based on a combination of machine learning algorithms and routine blood, biochemical and tumour marker indicators.

METHODS

In total, 697 complete samples were collected from four hospitals in Gansu Province, including 42 blood indicators from 318 pretreatment GST patients, 180 samples of gastric polyps and 199 healthy individuals. In this study, three algorithms, gradient boosting machine (GBM), random forest (RF), and logistic regression (LR), were chosen to build GST prediction models for comparison. The performance and stability of the models were evaluated using two different validation techniques: 5-fold cross-validation and external validation. The DeLong test assesses significant differences in AUC values by comparing different ROC curves, the variance and covariance of the AUC value.

RESULTS

The AUC values of both the GBM and RF models were higher than those of the LR model, and this difference was statistically significant (P < 0.05). The GBM model was considered to be the optimal model, as a larger area was enclosed by the ROC curve, and the axes indicated robust model classification performance according to the accepted model discriminant. Finally, the integration of 8 top-ranked blood indices was proven to be able to distinguish GST from gastric polyps and healthy people with sensitivity, specificity and area under the curve of 0.941, 0.807 and 0.951 for the cross-validation set, respectively.

CONCLUSION

The GBM demonstrated powerful classification performance and was able to rapidly distinguish GST patients from gastric polyps and healthy individuals. This identification system not only provides an innovative strategy for the diagnosis of GST but also enables the exploration of hidden associations between blood parameters and GST for subsequent studies on the prevention and disease surveillance management of GST. The GST discrimination system is available online for free testing of doctors and high-risk groups at https://jzlyc.gsyy.cn/bear/mobile/index.html .

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

Treatment Response Predictors of Neoadjuvant Therapy for Locally Advanced Gastric Cancer: Current Status and Future Perspectives

Neoadjuvant chemotherapy (NAC) for locally advanced gastric cancer (LAGC) has been recognized as an effective therapeutic option because it is expected to improve the curative resection rate by reducing the tumor size and preventing recurrence of micrometastases. However, for patients resistant to NAC, not only will operation timing be delayed, but they will also suffer from side effects. Thus, it is crucial to develop a comprehensive strategy and select patients sensitive to NAC. However, the therapeutic effect of NAC is unpredictable due to tumor heterogeneity and a lack of predictive biomarkers for guiding the choice of optimal preoperative treatment in clinical practice. This article summarizes the related research progress on predictive biomarkers of NAC for gastric cancer. Among the many investigated biomarkers, metabolic enzymes for cytotoxic agents, nucleotide excision repair, and microsatellite instability, have shown promising results and should be assessed in prospective clinical trials. Noninvasive liquid biopsy detection, including miRNA and exosome detection, is also a promising strategy.

MicroRNA-381 in human cancer: Its involvement in tumour biology and clinical applications potential

MicroRNAs (miRNAs) are small non‐coding RNAs that regulate gene expression at the post‐transcriptional level. MiRNAs are involved in the development and progression of a wide range of cancers. Among such cancer‐associated miRNAs, miR‐381 has been a major focus of research. The expression pattern and role of miR‐381 vary among different cancer types. MiR‐381 modulates various cellular behaviours in cancer, including proliferation, apoptosis, cell cycle progression, migration and invasion. MiR‐381 is also involved in angiogenesis and lymphangiogenesis, as well as in the resistance to chemotherapy and radiotherapy. MiR‐381 itself is regulated by several factors, such as long noncoding RNAs, circular RNAs and cytokines. Aberrant expression of miR‐381 in blood samples indicates that it can be used as a diagnostic marker in cancer. Tissue miR‐381 expression may serve as a prognostic factor for the clinicopathological characteristics of cancers and survival of patients. Metformin and icaritin regulate miR‐381 expression and present anticancer properties. This review comprehensively summarizes the effect of miR‐381 on tumour biological behaviours, as well as the clinical application potential of miR‐381 for the treatment of cancer.

Biomarker evaluation in radically resectable locally advanced gastric cancer treated with neoadjuvant chemotherapy: an evidence reappraisal

Neoadjuvant chemotherapy (NAC) significantly improved the prognosis of patients with locally advanced resectable gastric cancer but, despite important progresses, relapse-related death remains a major challenge. Therefore, it appears crucial to understand which patients will benefit from peri-operative treatment. Biomarkers such as human epidermal growth factor receptor-2 (HER2), microsatellite instability (MSI), and Epstein-Barr Virus (EBV) have been widely studied; however, they do not yet guide the choice of perioperative treatment in clinical practice. We performed a narrative review, including 23 studies, addressing the value of tissue- or blood-based biomarkers in the neoadjuvant setting. Ten studies (43.5%) were prospective, and more than half were conducted in East-Asia. Biomarkers were evaluated only post-NAC (on surgical samples or blood) in seven studies (30.4%), only pre-NAC (on endoscopic specimens or blood) in 10 studies (43.5%), and both pre- and post-NAC (26.1%) in six studies. Among the high variety of investigated biomarkers, some of these including MSI-H or enzymatic profile (as TS, UGT1A1, MTHFR, ERCC or XRCC) showed promising results and deserve to be assessed in methodologically sound clinical trials. The identification of molecular biomarkers in patients treated with NAC for locally advanced resectable gastric or EGJ cancer remains crucial.

The tRNA-derived fragment 5026a inhibits the proliferation of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway

Background

Recently, tRNA-derived fragments (tRFs) have been shown to serve important biological functions. However, the role of tRFs in gastric cancer has not been fully elucidated. This study aimed to identify the tumor suppressor role of tRF-5026a (tRF-18-79MP9P04) in gastric cancer.

Methods

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was first used to detect tRF-5026a expression levels in gastric cancer tissues and patient plasma. Next, the relationship between tRF-5026a levels and clinicopathological features in gastric cancer patients was assessed. Cell lines with varying tRF-5026a levels were assessed by measuring tRF-5026a using qRT-PCR. After transfecting cell lines with a tRF-5026a mimic or inhibitor, cell proliferation, colony formation, migration, apoptosis, and cell cycle were evaluated. The expression levels of related proteins in the PTEN/PI3K/AKT pathway were also analyzed by Western blotting. Finally, the effect of tRF-5026a on tumor growth was tested using subcutaneous tumor models in nude mice.

Results

tRF-5026a was downregulated in gastric cancer patient tissues and plasma samples. tRF-5026a levels were closely related to tumor size, had a certain diagnostic value, and could be used to predict overall survival. tRF-5026a was also downregulated in gastric cancer cell lines. tRF-5026a inhibited the proliferation, migration, and cell cycle progression of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway. Animal experiments showed that upregulation of tRF-5026a effectively inhibited tumor growth.

Conclusions

tRF-5026a (tRF-18-79MP9P04) is a promising biomarker for gastric cancer diagnostics and has tumor suppressor effects mediated through the PTEN/PI3K/AKT signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02497-1.

Prognostic value of miR-892a in gastric cancer and its regulatory effect on tumor progression

BACKGROUND

Gastric cancer is a prevalent malignant around the world. Aberrantly expression of microRNAs (miRNAs) contributes to the progression of tumors. The aim of this study was to investigate the expression and role of miR-892a in gastric cancer.

METHODS

A total of 119 gastric cancer patients were enrolled in this study. And the expression of miR-892a in gastric cancer tissues and cells was measured using RT-qPCR analysis. Kaplan-Meier plotter and multivariate Cox regression analysis were used to explore the prognostic value of miR-892a in gastric cancer. The biological function of miR-892a in gastric cancer cells was evaluated using CCK-8 assays and Transwell assays.

RESULTS

The expression of miR-892a was high-expressed in gastric cancer tissues and cells. The miR-892a expression was associated with tumor size, differentiation, lymph node metastasis, and TNM stages. Gastric cancer patients with high miR-892a expression showed a short overall survival rate. Overexpression of miR-892a promoted cell proliferation, migration, and invasion of gastric cancer cells.

CONCLUSION

miR-892a was upregulated and predictor of poor prognosis in gastric cancer patients. The miR-892a in gastric cancer cells significantly promoted cell proliferative, migratory, and invasive properties. Furthermore, miR-892a may be served as a prognostic marker as well as a therapeutic target for gastric cancer.

Elevated microRNA-7 inhibits proliferation and tumor angiogenesis and promotes apoptosis of gastric cancer cells via repression of Raf-1

OBJECTIVE

Since the essential involvement of microRNAs (miRNAs) in the development and progression of GC, the study was for the exploration of the value of microRNA-7 (miR-7) in the evaluation of neoadjuvant chemotherapy for gastric cancer (GC) and its effects on apoptosis, proliferation and angiogenesis of GC.

METHODS

miR-7 expression in serum of GC patients before and after neoadjuvant chemotherapy were detected to explore its role in neoadjuvant chemotherapy of GC. The GC cells were transfected with miR-7 mimics/inhibitors, or siRNA-Raf-1 to figure out their roles in proliferation, migration, invasion, cycle distribution and apoptosis. Tumor xenograft was conducted to test tumor growth. Microvessel density (MVD) in tumors was tested by immunohistochemical staining.

RESULTS

miR-7 expression in serum of GC patients was lower than that of healthy controls while it was elevated after neoadjuvant chemotherapy. Moreover, higher miR-7 expression was exhibited in chemotherapy-effective patients rather than chemotherapy-ineffective patients (P < 0.01). miR-7 expression in serum was connected with tumor size, degree of differentiation, TNM stage and lymphatic metastasis.miR-7 was decreased and Raf-1 was elevated in GC cells (both P < 0.05). Elevated miR-7 or declined Raf-1 inhibited GC cell migration, proliferation and invasion, cell cycle entry, xenografted tumor growth and MVD and stimulated apoptosis (all P < 0.05). Down-regulated Raf-1 reversed the impacts of miR-7 knockdown on GC cells (all P < 0.05).

CONCLUSION

Our study highlights that elevated miR-27a indicates the good efficacy of neoadjuvant chemotherapy in GC and miR-7 targets Raf-1 to suppress tumor development and angiogenesis of GC cells.

miR-212 as potential biomarker suppresses the proliferation of gastric cancer via targeting SOX4

Background

Circulating microRNAs that post‐transcriptionally regulate gene expressions have been reported as promising biomarkers in cancer monitoring. This study was to identify the potential role of circulating miR‐212 in gastric cancer and whether it could serve as a novel biomarker for gastric cancer.

Methods

We detected the serum levels of miR‐212 in 100 health people and 110 gastric cancer patients and analyzed the relationships of the serum level of miR‐212 with gastric cancer. We detected the expression of miR‐212 in human gastric mucosal epithelial cell line (GES‐1) and human gastric cancer cell lines (NCI‐N87 and SNU‐16) using qRT‐PCR. Then, we detected the role of 5‐aza‐deoxycytidine on the epigenetic regulation of miR‐212 in human gastric cancer cell lines. Furthermore, luciferase reporter assay was used to detect binding activity of miR‐212 on SOX4 mRNA, and their functions on the cell proliferation and apoptosis.

Results

The expression of miR‐212 was higher in health people than that in gastric cancer patients, higher in gastric mucosal epithelial cell line than that in gastric cancer cells. miR‐212 can be a circulating biomarker and an independent prognostic factor of gastric cancer. Moreover, miR‐212 can directly regulate the 3′UTR of SOX4 mRNA to suppress p53 and Bax, resulting gastric cancer cells proliferation inhibition and apoptosis induction.

Conclusion

Our study demonstrated that miR‐212 was epigenetically downregulated in gastric cancer, and resulting low level of miR‐212 can be a potential circulating biomarker and poor prognosis predicator of gastric cancer.

An insight into the roles of piRNAs and PIWI proteins in the diagnosis and pathogenesis of oral, esophageal, and gastric cancer

P-Element induced wimpy testis (PIWI)-interacting RNA (piRNA) is a member of the non-coding RNAs family. Four PIWI proteins are found to be expressed in humans. The number of studies focusing on the roles of piRNAs and PIWI proteins in the field of cancer is increasing. Oral, esophageal, and gastric cancers are considered as important causes of death. PIWI proteins and piRNAs are suggested to be involved in the pathogenesis of these diseases. Thus, studying these molecules may be beneficial for finding new therapeutics. Since it is shown that currently used biomarkers for these cancers have low sensitivity and specificity, there is a necessity for identifying novel non-invasive biomarkers which are highly sensitive and specific. This paper will provide an insight into current knowledge about the functions of PIWI proteins and piRNAs in the oral, esophageal, and gastric cancer. We discuss how PIWI proteins and piRNAs can be involved in the pathogenesis of these cancers. Moreover, we review the studies concerning with the roles of PIWI proteins and piRNAs as biomarkers which are used for diagnostic and prognostic purposes.

Overexpression of SOX4 induces up-regulation of miR-126 and miR-195 in LNCaP prostate cancer cell line

The present study aims to investigate the association between SOX4, Wnt signaling, and miRNAs under Wnt3 induction via bioinformatics analysis and functional essays. To briefly explore the expression of SOX4 protein in various types of cancer, we used ONCOMINE, a highly reputable cancer database, for comparison of its expression in prostate carcinoma relative to normal prostate gland. Concomitantly, we used CCLE to plot the copy number of SOX4 against its mRNA expression status in various cancerous cell lines to confirm the carcinogenesis role of SOX4. Afterward, whole profiling expression of microRNA in SOX4-stably expressed LNCaP cell line under the effect of Wnt3A were demonstrated. After identifying microRNA targets, STRING database and MIROB were used to explore the functional connection between proteins and microRNA with proteins. The results from our study shows that over-expressed of SOX4 was confirmed in both carcinogenesis tissue and cancer cell lines in Oncomine and CCLE database. In addition, five miRNAs, miR-16, miR-19a, miR320, miR-195, and miR-126, were differentially expressed in LNCaP cell line induced by Wnt3a. Pathway analysis of these targets proposed interaction networks of SOX4, Wnt3a with miR-126 and miR-195. Altogether, the miRNAs involved in Wnt and SOX4-mediated prostate cancer such as miR-126 and miR-195 could be potential biomarkers in prostate cancer.

GCdiscrimination: identification of gastric cancer based on a milliliter of blood

Gastric cancer (GC) continues to be one of the major causes of cancer deaths worldwide. Meanwhile, liquid biopsies have received extensive attention in the screening and detection of cancer along with better understanding and clinical practice of biomarkers. In this work, 58 routine blood biochemical indices were tentatively used as integrated markers, which further expanded the scope of liquid biopsies and a discrimination system for GC consisting of 17 top-ranked indices, elaborated by random forest method was constructed to assist in preliminary assessment prior to histological and gastroscopic diagnosis based on the test data of a total of 2951 samples. The selected indices are composed of eight routine blood indices (MO%, IG#, IG%, EO%, P-LCR, RDW-SD, HCT and RDW-CV) and nine blood biochemical indices (TP, AMY, GLO, CK, CHO, CK-MB, TG, ALB and γ-GGT). The system presented a robust classification performance, which can quickly distinguish GC from other stomach diseases, different cancers and healthy people with sensitivity, specificity, total accuracy and area under the curve of 0.9067, 0.9216, 0.9138 and 0.9720 for the cross-validation set, respectively. Besides, this system can not only provide an innovative strategy to facilitate rapid and real-time GC identification, but also reveal the remote correlation between GC and these routine blood biochemical parameters, which helped to unravel the hidden association of these parameters with GC and serve as the basis for subsequent studies of the clinical value in prevention program and surveillance management for GC. The identification system, called GC discrimination, is now available online at http://lishuyan.lzu.edu.cn/GC/.

Gastric juice piR-1245: A promising prognostic biomarker for gastric cancer

Background

Emerging reports demonstrated that PIWI‐interacting RNAs (piRNAs) played an indispensable role in tumorigenesis. However, it still remains elusive whether piR‐1245 in gastric juice specific in stomach could be employed as a biomarker for gastric cancer (GC). The present work is aiming at exploring the possibility of piR‐1245 in gastric juice as a potential marker to judge for diagnosis and prognosis of gastric cancer.

Methods

Gastric juice was collected from 66 GC patients and 66 healthy individuals. Quantitative real‐time reverse transcriptase polymerase chain reaction (qRT‐PCR) was employed to measure the levels of piR‐1245 expression. Then, the pattern of piR‐1245 expression in gastric juice was determined between GC patients and healthy individuals. A receiver operating characteristic (ROC) curve was constructed for distinguishing GC from healthy individuals.

Results

Gastric juice piR‐1245 levels in GC were higher than those of controls (P < .0001). The value of area under ROC (AUC) was 0.885 (sensitivity, 90.9%; specificity, 74.2%; 95% confidence interval, 0.8286 to 0.9414). High gastric juice piR‐1245 expression was signally correlated with tumor size (P = .013) and TNM stage (P = .001). GC patients with high piR‐1245 expression in gastric juice exerted a poorer overall survival (OS) (P = .0152) and progression‐free survival (PFS) (P = .013). COX regression analysis verified that gastric juice piR‐1245 expression was an independent prognostic risk variable for OS (P < .05).

Conclusions

The current study suggested that piR‐1245 in gastric juice had the potential to be a useful biomarker for GC detection and prognosis prediction.

Relationship between microRNA-27a and efficacy of neoadjuvant chemotherapy in gastric cancer and its mechanism in gastric cancer cell growth and metastasis

Objective: The aim of the present study is to investigate the relationship between microRNA-27a (miR-27a) and the efficacy of neoadjuvant chemotherapy in gastric cancer (GC) and its mechanism in the growth and metastasis of GC cells.

Methods: The expression of miR-27a in serum of 74 GC patients received neoadjuvant chemotherapy was detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Clinical value and prognosis of miR-27a expression in predicting the efficacy of neoadjuvant chemotherapy in GC were evaluated. Besides, GC cells with low miR-27a expression were transfected with miR-27a mimics, and cells with high miR-27a expression were transfected with miR-27a inhibitors and secreted frizzled-related protein 1 (SFRP1) siRNA. A series of experiments were applied for the determination of cell viability, invasion and migration of GC cells.

Results: After neoadjuvant chemotherapy, the expression of miR-27a in serum of GC patients decreased significantly. Additionally, the expression of miR-27a in GC cell line was significantly higher than that in normal gastric mucosa cell line. Meanwhile, after down-regulating the expression of miR-27a in GC cells, the mRNA and protein expression of SFRP1 increased, the proliferation rate of cells slowed down, and the ability of invasion and migration decreased. Furthermore, combined with low expression of miR-27a and SFRP1, the proliferation rate of GC cells increased and the ability of invasion and migration increased.

Conclusion: Collectively, our study highlights that the high expression of miR-27a indicates the poor efficacy and prognosis of neoadjuvant chemotherapy in GC patients. Down-regulation of miR-27a can inhibit the growth and metastasis of GC cells via up-regulation of SFRP1.

Vasodilator-stimulated phosphoprotein (VASP), a novel target of miR-4455, promotes gastric cancer cell proliferation, migration, and invasion, through activating the PI3K/AKT signaling pathway

Background

MicroRNAs (miRNAs) are small non-coding RNAs which play important roles in the carcinogenesis of gastric cancer (GC). Expression profiling of miRNAs in paired gastric cancer and adjacent normal gastric tissues has demonstrated that miR-4455 is down-regulated in gastric cancer tissues, but its functional role in the carcinogenesis of GC had not previously been investigated.

Aims

The purpose of this study was to investigate the functional and biological mechanisms of miR-4455 in the progression of GC, in vitro.

Methods

Expression of miR-4455 was compared in human GC tissue samples and paired adjacent normal tissue samples. The in vitro effects of miR-4455 expression in MGC-803 cells on their proliferation, invasion, and migration were assessed by MTT assays and 5-bromo-2′-deoxyuridine staining, matrigel-invasion analysis and wound healing assays. Bioinformatics analysis (using PicTar, target scan and miRBase target) was used to identify potential targets for miR-4455, and the luciferase reporter assay, qRT-PCR and Western-blotting analyses were used to confirm VASP as the target of miR-4455. In addition, the effects of downregulation of VASP on the activation of PI3K/AKT signaling pathway were measured using Western-blot analysis.

Results

The expression of miR-4455 was markedly down-regulated in gastric cancer tissues vs. adjacent normal tissues, and miR-4455 expression inhibited the proliferation, invasion and migration of MGC-803 GC cells in vitro. Luciferase reporter assays revealed that miR-4455 inhibited VASP expression by targeting the 3′-UTR sequence of VASP. Furthermore, silencing of VASP markedly inhibited the activation of the PI3K/AKT signaling pathway.

Conclusion

Our results suggest that miR-4455 functions as a tumor suppressor in gastric cancer, by targeting VASP leading to activation of the PI3K/AKT signaling pathway and the inhibition of VASP mediated proliferation, migration and invasion of gastric cancer cells.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0573-4) contains supplementary material, which is available to authorized users.

Clinical value of peripheral blood microRNA detection in evaluation of SOX regimen as neoadjuvant chemotherapy for gastric cancer

BACKGROUND

Neoadjuvant chemotherapy has been widely applied in treating advanced gastric cancer (GC). However, little research has been conducted on evaluating the effect of neoadjuvant chemotherapy. Purpose of this study was to evaluate the effect of SOX regimen as neoadjuvant chemotherapy by detecting some microRNAs.

METHODS

Total 120 GC patients who had received neoadjuvant chemotherapy (SOX regimen) were recruited with 100 healthy participants as control contemporarily. Age and gender have no significant difference in both groups (P > .05). The effect of chemotherapy was evaluated by the results of CT scan and surgery. Also, adverse effects of chemotherapy were documented. Peripheral blood of GC patients was collected twice: one day before chemotherapy and surgery, respectively, whereas healthy controls' peripheral blood was collected once. Quantitative real-time PCR (qPCR) was utilized to detect expression of miR-145, miR-185, miR-381, and miR-195 of peripheral blood in both groups.

RESULTS

One hundred and twenty patients with advanced GC completed a total of 386 cycles of neoadjuvant chemotherapy with effective rate at 84.17% (101 of 120). Expression of miR-145, miR-185, and miR-381 of patients with GC was lower than that in the control group before chemotherapy commence (all P < .05), while the expressions of miR-145 and miR-185 elevated noticeably in CG patients after neoadjuvant chemotherapy (P < .05). The differences in the expression of miR-145 and miR-185 in advanced GC patients with different chemotherapy outcomes were detected.

CONCLUSION

Patients with GC at advanced stages had aberrant miRs expressions. Detection of miR-145 and miR-185 expression may assist to predict effectiveness and adverse effects of SOX regimen as neoadjuvant chemotherapy.