Surgical resection of metachronous hepatic metastases from gastric cancer improves long-term survival: A population-based study

Genomic biology and therapeutic strategies of liver metastasis from gastric cancer

The liver is a frequent site of metastasis in advanced gastric cancer (GC). Despite significant advancements in diagnostic and therapeutic techniques, the overall survival rate for patients afflicted with gastric cancer liver metastasis (GCLM) remains dismally low. Precision oncology has made significant progress in identifying therapeutic targets and enhancing our understanding of metastasis mechanisms through genome sequencing and molecular characterization. Therefore, it is crucial to have a comprehensive understanding of the various molecular processes involved in GCLM and the fundamental principles of systemic therapy to develop new treatment approaches. This paper aims to review recent findings on the diagnosis, potential biomarkers, and therapies targeting the multiple molecular processes of GCLM, with the goal of improving treatment strategies for patients with GCLM.

Prognostic Role of Preoperative Chemotherapy in Liver-Limited Metastasis from Gastric Cancer

BACKGROUND

We investigated the prognostic role of preoperative chemotherapy in patients who underwent hepatectomy for liver-limited metastasis (LLM) from gastric cancer (GC).

METHODS

A retrospective analysis was conducted for 52 consecutive patients who underwent macroscopically complete (R0 or R1) resection for synchronous or metachronous LLM from GC.

RESULTS

Of the 52 patients, 18 (35%) received preoperative chemotherapy (PC group), while 34 (65%) underwent upfront surgery (US group). The PC group had a significantly longer overall survival than the US group (cumulative 5-year OS rate: 47.6% vs. 24.8%, p = 0.041). Multivariate analysis of OS revealed that preoperative chemotherapy was an independent favorable prognostic factor (hazard ratio: 0.445, p = 0.036). Patients showing a partial response to preoperative chemotherapy on RECIST had an improved OS compared with those exhibiting stable or progressive disease after preoperative chemotherapy and with US (p = 0.025), even among those with solitary LLM (p = 0.062) and multiple LLM (p = 0.026). At recurrence after hepatectomy for LLM, the PC group had a significantly higher incidence of solitary tumors than the US group (p = 0.043) and had a higher chance to undergo surgical resection for recurrent sites (p = 0.006).

CONCLUSIONS

Preoperative chemotherapy can be recommended for patients with LLM from GC. The evaluation of the efficacy of preoperative chemotherapy offers additional information to determine the surgical indication for LLM.

Influence of cancer-directed surgery on the prognosis of liver metastases from gastric cancer

There are controversial about the application of cancer-directed surgery (CDS) in patients with liver metastases from gastric cancer, with improved responses to chemotherapy and targeted treatments, the role of CDS in metastatic gastric cancer to the liver needs to be revisited. This study aimed to evaluate the effect of CDS on patients with liver metastases from gastric cancer. Data for patients with liver metastases from gastric cancer were extracted from the population-based Surveillance, Epidemiology, and End Results (SEER) database. A total of 958 individuals were enrolled, 285 in the CDS group and 673 in the non-cancer guided surgery (Non-CDS) group. Following propensity score matching (PSM) analysis at 1:1 in the two groups,285 were included in the survival analysis for each group. Kaplan-Meier values and Cox proportional risk models were used to estimate the effect of CDS on patients' prognoses. Compared with the Non-CDS group, the CDS group significantly prolonged the median overall survival from 4 months (95% confidence interval [CI] 3-5) to 11 months (95% CI 8-12), p value < 0.001. Overall survival (OS) at 1 year was higher in the CDS group than in the Non-CDS group, at 44% (95 CI 38-50) and 25% (95 CI 20-30), respectively. OS at 3 years was also higher in the CDS group than in the Non-CDS group, at 24% (95 CI 19-29) and 6% (95 CI 3-9), respectively. Multivariate analysis showed that Non-CDS (hazard ratio[HR] = 2.26, 95% CI 1.88-2.72, p value < 0.001) was an adverse independent prognostic factor for patients. This study concludes that CDS prolonged survival in patients with gastric cancer with liver metastases. Due to the lack of information on the quality of life, biomarkers, targeted therapies, and immunotherapy in the SEER database, the observed improved survival rates following CDS of hepatic metastasis from gastric cancer requires prospective studies that take these factors into account to properly address the survival advantages and impact on quality of life of such a method.

Survival Outcomes of Hepatectomy in Gastric Cancer Liver Metastasis: A Systematic Review and Meta-Analysis

Gastric cancer liver metastasis (GCLM) is a contraindication for surgical treatment in current guidelines. However, the results of recent studies are questioning this paradigm. We assessed survival outcomes and their predictors following hepatectomy for GCLM in a systematic review of studies published from 2000 to 2022 according to PRISMA guidelines. We identified 42,160 references in four databases. Of these, 55 articles providing data from 1990 patients fulfilled our criteria and were included. We performed a meta-analysis using random-effects models to assess overall survival (OS) and disease-free survival (DFS) at one, three, and five years post-surgery. We studied the impact of potential prognostic factors on survival outcomes via meta-regression. One, three, and five years after surgery, OS was 69.79%, 34.79%, and 24.68%, whereas DFS was 41.39%, 23.23%, and 20.18%, respectively. Metachronous presentation, well-to-moderate differentiation, small hepatic tumoral size, early nodal stage, R0 resection, unilobar compromisation, and solitary lesions were associated with higher overall survival. Metachronous presentation, smaller primary tumoral size, and solitary metastasis were linked to longer DFS. The results of our meta-analysis suggest that hepatectomy leads to favorable survival outcomes in patients with GCLM and provides data that might help select patients who will benefit most from surgical treatment.

Survival benefit of primary tumor resection for gastric cancer with liver metastasis: A propensity score-matched, population-based study

OBJECTIVES

Gastric cancer with liver metastasis (GCLM) is highly aggressive and has a poor prognosis. This study aims to evaluate the survival benefit of primary tumor resection (PTR) for gastric cancer with liver metastasis.

METHODS

Data on patients with GCLM was extracted from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. A 1:1 propensity score matching (PSM) analysis was performed to minimize the heterogeneity between the PTR and no-PTR groups. The Kaplan-Meier method and Cox regression analysis were used to assess the impact of primary tumor resection (PTR) on overall survival (OS) and cause-specific survival (CSS).

RESULTS

A total of 3,001 patients with GCLM were included, with 328 patients treated with primary tumor resection (PTR), whereas the other 2,673 patients were not. Patients with PTR had a significantly higher OS and CSS rate than those without PTR in unmatched and PSM cohorts. In an unmatched cohort, the median OS was 12.0 months (95% CI, 10 months to 14 months) for those who underwent PTR and 4 months (95% CI, 4 months to 5 months) for those without PTR; the median CSS for those who underwent PTR was 12.0 months (95% CI, 10 months to14 months) and 4 months (95% CI, 4 months to 5 months) for those without PTR, respectively. After PMS, the median OS was 12.0 months (95% CI, 10 months to 17 months) for those who underwent PTR and 7 months (95% CI, 5 months to 10 months) for those without PTR, respectively; the median CSS for those who underwent PTR was 12.0 months (95% CI, 11 months to 17 months) and 7 months (95% CI, 5 months to 8 months) for those without PTR, respectively. In addition, multivariate Cox analysis in the PSM cohort showed that PTR, age, degree of tumor differentiation, and chemotherapy were independent prognostic factors for OS and CSS in GCLM. Specifically, PTR was a significant protective factor for OS (HR: 0.427; 95% CI, 0.325 to 0.561, P <0.001) and CSS (HR: 0.419; 95% CI, 0.313 to 0.561, P <0.001).

CONCLUSION

Primary tumor resection improves the survival of gastric cancer patients with liver metastasis.

SERPINA5 promotes tumour cell proliferation by modulating the PI3K/AKT/mTOR signalling pathway in gastric cancer

SERPINA5 belongs to the serine protease inhibitor superfamily and has been reported to be lowly expressed in a variety of malignancies. However, few report of SERPINA5 in gastric cancer has been found. The purpose of this study was to determine the role of SERPINA5 in GC and to investigate potential tumorigenic mechanisms. We performed qPCR to determine the level of SERPINA5 expression in GC. We used public databases to evaluate whether SERPINA5 could be utilized to predict overall survival and disease‐free survival in GC patients. We also knocked down the expression of SERPINA5 and evaluated its effect on cell proliferation and migration. Furthermore, we explored the signal pathways and regulatory mechanisms related to SERPINA5 functions. According to our findings, SERPINA5 was shown to exhibit high expression in GC. Notably, SERPINA5 was prognostic in GC with high expression being unfavourable. SERPINA5 was further observed to promote GC tumorigenesis by modulating GC cell proliferation ability. Mechanically, SERPINA5 could inhibit CBL to regulate the PI3K/AKT/mTOR signalling pathway, thereby promoting GC carcinogenesis progression. These results highlight the important role of SERPINA5 in GC cell proliferation and suggest that SERPINA5 could be a novel target for GC treatment and a predictor for GC prognosis.

Surgery is Associated With Improved Overall Survival in Patients With Metastatic Gastric Cancer: A National Cancer Database Analysis

BACKGROUND

The 5-year overall survival (OS) rate for patients with metastatic gastric cancer (mGC) is 5.3%. Surgery for mGC is controversial.

METHODS

We identified all mGC patients who received chemotherapy using the National Cancer Database (2004-2015). Patients were grouped according to surgery of: (1) the primary site (PS) only, (2) primary and distant sites (PDS), (3) distant site only (DS), or (4) no surgery (NS). A propensity score adjustment and multivariate regression was used to compare OS.

RESULTS

Overall, 18,772 patients met the inclusion criteria: (1) PS (n = 962, 5.1%), (2) PDS (n = 380, 2.1%), (3) DS (n = 984, 5.2%), and 16,446 NS (87.6%). Surgery was associated with improved OS in the PS and PDS groups (hazard ratios: .489 (95% CI: .376-.636); .583 (95% CI: .420-.811), P < .001) (median OS 15.8 and 15.9 months vs 8.6 for NS patients, respectively).

CONCLUSIONS

Gastrectomy with or without metastasectomy is associated with improved survival in stage IV gastric cancer patients receiving chemotherapy. This warrants further prospective studies.

ω-3 and ω-6 Polyunsaturated Fatty Acids Regulate the Proliferation, Invasion and Angiogenesis of Gastric Cancer Through COX/PGE Signaling Pathway

Background

This study aims to investigate the effects of ω-3, ω-6 polyunsaturated fatty acids (PUFAs), and their middle metabolites prostaglandin (PGE)2 and PGE3 on proliferation, invasion, and angiogenesis formation of gastric cancer cells and to explore associated mechanism.

Methods

RT-PCR and ELISA were used to detect the expression of cyclooxygenase (COX)-1 and COX-2 in gastric cancer cell lines. The effect of ω-3, ω-6, PGE2, and PGE3 on the proliferation, invasion, and angiogenesis of gastric cancer cells were measured by cell proliferation, invasion, and angiogenesis assay in vitro. COX-2 small interfering RNA (siRNA) was transfected into gastric cancer cells, and the expression of COX-2 protein was detected by Western blot. COX-2 gene silencing influencing proliferation, invasion, and angiogenesis potential of gastric cancer cells was detected by WST-1, transwell chamber, and angiogenesis assay, respectively.

Results

COX-2 was only expressed in MKN74 and MKN45 cells. In gastric cancer cell lines with positive COX-2 expression, ω-6 and PGE2 could significantly enhance the proliferation, invasion, and angiogenesis of gastric cancer cells, and after transfection with COX-2 siRNA, the effects of ω-6 and PGE2 on enhancing the proliferation, invasion, and angiogenesis of gastric cancer cells were significantly attenuated; ω-3 and PEG3 could inhibit the proliferation, invasion, and angiogenesis of gastric cancer cells. In gastric cancer cell lines with negative COX-2 expression, ω-6 and PGE2 had no significant effect on the proliferation, invasion, and angiogenesis of gastric cancer; ω-3 and PGE3 could significantly inhibit the proliferation, invasion, and angiogenesis of gastric cancer.

Conclusion

ω-6 PUFAs reinforce the metastatic potential of gastric cancer cells via COX-2/PGE2; ω-3 PUFAs inhibit the metastatic potential of gastric cancer via COX-1/PGE3 signaling axis.

Identifying Optimal Surgical Intervention-Based Chemotherapy for Gastric Cancer Patients With Liver Metastases

BACKGROUND

This study aimed at evaluating the effects of surgical treatments-based chemotherapy in the treatment of gastric cancer with liver metastases (GCLM). It has not been established whether Liver-directed treatment (LDT) options such as hepatectomy and gastrectomy plus chemotherapy (HGCT), radiofrequency ablation and gastrectomy plus chemotherapy (RFAG), transarterial chemoembolization and gastrectomy plus chemotherapy (TACEG), gastrectomy plus chemotherapy (GCT) enhance the survival of GCLM patients.

METHODS

We performed systematic literature searches in PubMed, EMBASE, and Cochrane library from inception to September 2021. We created a network plot to comprehensively analyze the direct and indirect evidence, based on a frequentist method. A contribution plot was used to determine inconsistencies, a forest plot was used to evaluate therapeutic effects, the publication bias was controlled by funnel plot, while the value of surface under the cumulative ranking curves (SUCRA) was calculated to estimate rank probability.

RESULTS

A total of 23 retrospective studies were identified, involving 5472 GCLM patients. For OS and 1-, 2-, 3-year survival rate of all trials, meta-analysis of the direct comparisons showed significant better for HGCT treatments compared with GCT or PCT. In the comparison of the 5 treatments for 1-, 2-, 3-year survival rate, HGCT and RFAG were found to be more effective than GCT and PCT, respectively. By OS and 2-, 3-year survival rate analysis, RFAG was identified as the best option, followed by HGCT, TACEG, GCT and PCT. By 1-year survival rate analysis, HGCT and RFAG were identified as the most effective options.

CONCLUSION

HGCT and RFAG has remarkable survival benefits for GCLM patients when compared to TACEG, GCT and PCT. HGCT was found to exhibit superior therapeutic effects for GCLM patients for 1-year survival rate while RFAG was found to be a prospective therapeutic alternative for OS and 2-, 3-year survival rate.

SYSTEMATIC REVIEW REGISTRATION

identifier [10.37766/inplasy2020.12.0009].

Efficacy of Surgery for the Treatment of Gastric Cancer Liver Metastases: A Systematic Review of the Literature and Meta-Analysis of Prognostic Factors

BACKGROUND

In the last 10 years, the management of patients with gastric cancer liver metastases (GCLM) has changed from chemotherapy alone, towards a multidisciplinary treatment with liver surgery playing a leading role. The aim of this systematic review and meta-analysis is to assess the efficacy of hepatectomy for GCLM and to analyze the impact of related prognostic factors on long-term outcomes.

METHODS

The databases PubMed (Medline), EMBASE, and Google Scholar were searched for relevant articles from January 2010 to September 2020. We included prospective and retrospective studies that reported the outcomes after hepatectomy for GCLM. A systematic review of the literature and meta-analysis of prognostic factors was performed.

RESULTS

We included 40 studies, including 1573 participants who underwent hepatic resection for GCLM. Post-operative morbidity and 30-day mortality rates were 24.7% and 1.6%, respectively. One-year, 3-years, and 5-years overall survival (OS) were 72%, 37%, and 26%, respectively. The 1-year, 3-years, and 5-years disease-free survival (DFS) were 44%, 24%, and 22%, respectively. Well-moderately differentiated tumors, pT1-2 and pN0-1 adenocarcinoma, R0 resection, the presence of solitary metastasis, unilobar metastases, metachronous metastasis, and chemotherapy were all strongly positively associated to better OS and DFS.

CONCLUSION

In the present study, we demonstrated that hepatectomy for GCLM is feasible and provides benefits in terms of long-term survival. Identification of patient subgroups that could benefit from surgical treatment is mandatory in a multidisciplinary setting.

Bariatric Surgery Decreases the Risk of Non-traffic Accident-Related Fractures in Patients with Obesity: Real-world Data from Taiwan

OBJECTIVES

The aim of this study is to investigate the impact of bariatric surgery on non-traffic accident-related fractures in patients with obesity.

METHODS

This retrospective cohort study was conducted using the Taiwan National Health Insurance Research Database. Patients aged 18 to 55 years with obesity diagnosis between 2003 and 2008 were enrolled and divided into two groups: non-surgical and bariatric surgery groups. Patients with endocrine bone disease and malignancy history were excluded. Healthy patients were also randomly selected from the database and assigned to the general population group. The development of fracture was the primary end point. All patients were followed until the end of 2013 or death, whichever came first.

RESULTS

After propensity score matching, 1322, 1322, and 4359 subjects were included in the bariatric surgery (BS), non-surgical (NS), and general population (GP) groups, respectively. Based on multivariate analysis, the risk of overall fractures is similar between the BS group (hazard ratio [HR] = 0.774, p = 0.164) and the NS group; nevertheless, the risk of overall fractures was higher in the BS group (HR = 2.210, p<0.001) than in the GP group. The BS group had a significantly lower risk of non-traffic accident-related fractures (HR = 0.542, p = 0.010) than the NS group but a higher risk of non-traffic accident-related fractures (HR = 1.693, p = 0.023) than the GP group.

CONCLUSIONS

Bariatric surgery may decrease the risk of non-traffic accident-related fractures; however, the risk remains higher in patients with obesity than in the general population.

Decreased Long-Term Respiratory Infection Risk After Bariatric Surgery: a Comprehensive National Cohort Study

PURPOSE

This study aims to determine whether bariatric surgery (BS) decreases the risk of respiratory tract infections (RTIs) in obese patients.

MATERIALS AND METHODS

This retrospective, population-based, matched cohort study utilized data from the Taiwan National Health Insurance Research Database. All patients 18 to 55 years of age with obesity diagnosed between 2005 and 2010 were enrolled. Patients were separated into two groups based on whether they underwent BS. Two groups were selected using 1:1 propensity score matching according to age, sex, and comorbidities. The general population was also enrolled for comparison. The primary endpoint was the incidence of RTIs, including pneumonia, influenza, and bronchitis. All patients were followed up until the end of 2013, the primary endpoint, or death.

RESULTS

Compared to the non-surgery group, the BS group was at significantly lower risk for RTIs (aHR 0.432, 95% CI 0.340-0.549, p < 0.001) with shorter length of hospital stay (LOH) and lower cost. Regardless of the RTI-related mortality, pneumonia, influenza, and bronchitis rates, BS did have significant protective effects on the non-surgery group. Compared to the general population, the BS group was at higher risk for RTIs (aHR 3.601, 95% CI 2.742-4.728, p < 0.001) with similar LOH and lower cost.

CONCLUSION

Patients with obesity who underwent BS were at significantly lower risk for RTIs than obese patients who did not undergo BS but were at higher risk for RTIs than the general population. BS may result in a long-term reduction of the RTI risk.

The Increasing Possibility of Pregnancy Postbariatric Surgery: a Comprehensive National Cohort Study in Asian Population

PURPOSE

The present study aimed to investigate bariatric surgery's effects on pregnancy in obese women.

MATERIALS AND METHODS

The source of the data was the Taiwan National Health Insurance Research Database. We extracted female patients aged 18 to 45 years who had been diagnosed with obesity from 2005 to 2010. Two groups were formed based on bariatric surgery, according to the medical procedure codes of ICD-9-2001. The propensity score match of 1:1 was coordinated, based on the age, previous delivery, and the existence of comorbidities in patients. The primary endpoint was regarded as a pregnancy, including abortion, ectopic pregnancy, and delivery. The follow-up was performed until the end of 2013, or death.

RESULTS

There were 689 patients placed in each group, with a median of 64.8 follow-up months. Following multivariate analysis of the data, bariatric surgery resulted in significantly higher chances for pregnancy (aHR 2.886, p < 0.001) and resulted in a higher chance of successful delivery (aHR 2.775, p < 0.001) and vaginal delivery (aHR = 6.426, p < 0.001) compared with NS group. Moreover, we identified BS has a significantly higher proportion of vaginal delivery (BS 44.74% vs. NS 20%, p = 0.025) with significantly lower overall complications during labor (BS 9.21% vs. NS 33.3%, p = 0.006).

CONCLUSION

Patients suffering from obesity who undergo bariatric surgery have higher chances of pregnancy, successful delivery, vaginal delivery, and lower maternal complications during labor. Bariatric surgery did increase the possibility of pregnancy in obese patients.

Is there a role for treatment-oriented surgery in liver metastases from gastric cancer?

BACKGROUND

Distant metastases are found in approximately 35% of patients with gastric cancer at their first clinical observation, and of these, 4%-14% involves the liver. Unfortunately, only 0.4%-2.3% of patients with metastatic gastric cancer are eligible for radical surgery. Although surgical resection for gastric cancer metastases is still debated, there have been changes in recent years, although several clinical issues remain to be defined and that must be taken into account before surgery is proposed.

AIM

To analyze the clinicopathological factors related to primary gastric tumor and metastases that impact the survival of patients with liver metastatic gastric cancer.

METHODS

We performed a systematic review of the literature from 2000 to 2018 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The study protocol was based on identifying studies with clearly defined purpose, eligibility criteria, methodological analysis, and patient outcome.

RESULTS

We selected 47 studies pertaining to the purpose of the review, which involved a total of 2304 patients. Median survival was 7-52.3 mo, median disease-free survival was 4.7-18 mo. The 1-, 2-, 3-, and 5-year overall survival (OS) was 33%-90.1%, 10%-60%, 6%-70.4%, and 0%-40.1%, respectively. Only five papers reported the 10-year OS, which was 5.5%–31.5%. The general recurrence rate was between 55.5% and 96%, and that for hepatic recurrence was between 15% and 94%.

CONCLUSION

Serous infiltration and lymph node involvement of the primary cancer indicate an unfavorable prognosis, while the presence of single metastasis or ≤ 3 metastases associated with a size of < 5 cm may be considered data that do not contraindicate liver resection.

Surgery Strategies for Gastric Cancer With Liver Metastasis

Gastric cancer with liver metastasis is defined as advanced gastric cancer and remains one of the deadliest diseases with poor prognosis. Approximately 4–14% of patients with gastric cancers presented with liver metastases at the initial diagnosis. Owing to its incurability, first-line treatment for gastric cancer with liver metastases is systematic chemotherapy, whereas surgery is usually performed to alleviate severe gastrointestinal symptoms. However, continuously emerging retrospective studies confirmed the role of surgery in gastric cancer with liver metastases and showed significantly improved survival rate in patients assigned to a group of surgery with or without chemotherapy. Therefore, more and more convincing data that resulted from prospective randomized clinical trials is in need to clarify the surgery strategies in patients with gastric cancer with liver metastasis.

Hepatectomy for Liver Metastasis of Gastric Cancer: A Meta-Analysis

Background. Management of gastric cancer (GC) with liver metastases is debated. It is still controversial whether surgical resection provides a survival benefit or not. This systematic review was designed to evaluate the efficacy of hepatectomy for GC liver metastasis. Methods. We searched several electronic databases to identify eligible studies updated on September 2018. Studies assessing the efficacy and safety of hepatectomy versus no hepatectomy were included. Odds ratio (OR) along with 95% confidence interval (95% CI) were utilized for main outcome analysis. Results. In all, 10 studies were included. Patients who underwent hepatectomy had lower 1-year (OR = 0.15, 95% CI = 0.10-0.22, P < .00001), 3-year (OR = 0.16, 95% CI = 0.10-0.27, P < .00001), and 5-year mortality (OR = 0.13, 95% CI = 0.07-0.24, P < .00001) than those without hepatectomy. We also reported favorable survival outcome in patients with metachronous hepatic resection versus synchronous hepatic resection (OR = 2.09, 95% CI = 1.21-3.60, P = .008). However, there was no significant difference between solitary and multiple liver metastases (OR = 0.61, 95% CI = 0.35-1.07, P = .08). Conclusion. The present study demonstrates that hepatic resection in the management of liver metastases of GC can prolong the survival of patients and should be considered a promising treatment for such patients. Furthermore, there are more favorable outcomes in patients with metachronous metastases versus those with synchronous disease. Therefore, metachronous hepatic metastases from GC are not necessarily a contraindication for hepatectomy of the metastatic site.

TM4SF1 inhibits apoptosis and promotes proliferation, migration and invasion in human gastric cancer cells

Gastric cancer (GC) is associated with poor patient prognosis, and so it crucial to investigate the molecular mechanisms underlying the progression of GC. The aim of the present study was to investigate the role of transmembrane-4 L6 family member 1 (TM4SF1) in the progression of GC. TM4SF1 small interfering RNA (siRNA) and TM4SF1-expressing plasmids were employed to regulate TM4SF1 expression. In vitro experiments were performed to determine the effect of TM4SF1 on the expression of apoptosis-associated molecules and determine the role of TM4SF1 in apoptosis, proliferation, migration and invasion using human GC cell lines MGC803 and MKN45. The data of the present study demonstrated that TM4SF1 may regulate the expression of apoptosis-associated molecules at the mRNA and protein levels. TM4SF1 silencing reduced B-cell lymphoma 2 (Bcl2) expression, whilst caspase-3 and Bcl2-associated X expression increased, and upregulating TM4SF1 reversed these changes in GC cells. Furthermore, TM4SF1 knockdown promoted apoptosis while inhibiting the proliferation, migration and invasion of GC cells. Rescue experiments demonstrated that TM4SF1 upregulation reversed the changes induced by transfection with TM4SF1 siRNA. In summary, TM4SF1 is an anti-apoptosis protein associated with the progression of GC. Additional in vivo experiments and clinical trials are required to confirm the possible use of TM4SF1 in tumor therapy.

LGR6 promotes the progression of gastric cancer through PI3K/AKT/mTOR pathway

Background

In the present study, we aimed to investigate the role of LGR6 in the progression of gastric cancer (GC) and explore the intrinsic molecular mechanisms.

Materials and methods

The lentiviral LGR6 shRNA (sh-LGR6) and lentiviral expression vector of LGR6 gene (OE-LGR6) were used to regulate the LGR6 expression. Furthermore, we performed in vitro experiments to observe whether PI3K/AKT/mTOR pathway was affected by LGR6 and assess the role of LGR6 in the proliferation, apoptosis, migration, and invasion of GC cells.

Results

Our data showed that phosphorylated AKT and mTOR were downregulated by sh-LGR6 (P<0.05). The expressions of proapoptotic proteins Bax and Caspase-3 were upregulated by sh-LGR6 (P<0.05); the expression of antiapoptotic protein Bcl2 was downregulated by sh-LGR6 (P<0.001). Besides, the functional experiments proved that sh-LGR6 could promote the apoptosis of GC cells and inhibit the proliferation, invasion, and migration of GC cells (P<0.001). Compared with sh-LGR6, OE-LGR6 led to the opposite results.

Conclusion

LGR6 is an antiapoptosis protein which controls the progression of GC through PI3K/AKT/mTOR pathway. More in vivo experiments and clinical trials are necessary to confirm the possibility of LGR6 in tumor therapy.