Predictive factors of trastuzumab-based chemotherapy in HER2 positive advanced gastric cancer: a single-center prospective observational study

Establishment and evaluation of a prognostic model for patients with unresectable gastric cancer liver metastases

BACKGROUND

Liver metastases (LM) is the primary factor contributing to unfavorable outcomes in patients diagnosed with gastric cancer (GC). The objective of this study is to analyze significant prognostic risk factors for patients with GCLM and develop a reliable nomogram model that can accurately predict individualized prognosis, thereby enhancing the ability to evaluate patient outcomes.

AIM

To analyze prognostic risk factors for GCLM and develop a reliable nomogram model to accurately predict individualized prognosis, thereby enhancing patient outcome assessment.

METHODS

Retrospective analysis was conducted on clinical data pertaining to GCLM (type III), admitted to the Department of General Surgery across multiple centers of the Chinese PLA General Hospital from January 2010 to January 2018. The dataset was divided into a development cohort and validation cohort in a ratio of 2:1. In the development cohort, we utilized univariate and multivariate Cox regression analyses to identify independent risk factors associated with overall survival in GCLM patients. Subsequently, we established a prediction model based on these findings and evaluated its performance using receiver operator characteristic curve analysis, calibration curves, and clinical decision curves. A nomogram was created to visually represent the prediction model, which was then externally validated using the validation cohort.

RESULTS

A total of 372 patients were included in this study, comprising 248 individuals in the development cohort and 124 individuals in the validation cohort. Based on Cox analysis results, our final prediction model incorporated five independent risk factors including albumin levels, primary tumor size, presence of extrahepatic metastases, surgical treatment status, and chemotherapy administration. The 1-, 3-, and 5-years Area Under the Curve values in the development cohort are 0.753, 0.859, and 0.909, respectively; whereas in the validation cohort, they are observed to be 0.772, 0.848, and 0.923. Furthermore, the calibration curves demonstrated excellent consistency between observed values and actual values. Finally, the decision curve analysis curve indicated substantial net clinical benefit.

CONCLUSION

Our study identified significant prognostic risk factors for GCLM and developed a reliable nomogram model, demonstrating promising predictive accuracy and potential clinical benefit in evaluating patient outcomes.

Identifying HER2 from serum-derived exosomes in advanced gastric cancer as a promising biomarker for assessing tissue HER2 status and predicting the efficacy of trastuzumab-based therapy

PURPOSE

This study aimed to evaluate the clinical relevance of exosomal HER2 (Exo HER2) level in assessing the tissue HER2 status and predicting the efficacy of trastuzumab treatment.

METHODS

In this prospective study, patients with advanced gastric cancer (AGC) from three hospitals between August 2016 to November 2020 were enrolled. The Exo HER2 level was detected by enzyme-linked immunosorbent assay. Receiver operating characteristic curve (ROC) was drawn referring to the HER2 tissue status to assess the diagnostic value of Exo HER2. Cox proportional hazards regression and logistic regression were used to evaluate the association between Exo HER2 and progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) in patients who received trastuzumab-based first-line therapy.

RESULTS

In this study, 242 patients with advanced or metastatic gastric adenocarcinoma were registered. Of these, 238 AGC patients were eligible for evaluating serum-derived exosome HER2 diagnostic value, including 114 HER2-positive. Finally, 64 were eligible for efficacy analysis. The area under the ROC curve was 0.746. The optimal cutoff value for diagnosing tissue HER2-positive status was 729.95 ng/ml, with a sensitivity of 66.7% and a specificity of 74.2%. In 64 patients treated with trastuzumab, higher baseline Exo HER2 level indicated better prognosis. 844 ng/ml and 723 ng/ml were the right cutoffs for distinguishing the population with superior PFS (hazard ratio [HR] = 0.41, P = 0.017) and OS (HR = 0.30, P < 0.001), respectively.

CONCLUSION

Serum exosomal HER2 level might serve as an effective biomarker for assessing tissue HER2 status in AGC and screening the potential patients who might benefit from anti-HER2 therapy.

Contribution of microRNA-30d to the prevention of the thyroid cancer occurrence and progression: mechanism and implications

Thyroid cancer is a major endocrine tumor and represents an emerging health problem worldwide. MicroRNAs (miRNAs) have been addressed to participate in the pathogenesis and progression of thyroid cancer. However, it remains largely unknown what functions miR-30d may exert on thyroid cancer. This study, herein, aimed to identify the functional significance and machinery of miR-30d in the progression of thyroid cancer. MiR-30b presented aberrant low expression and ubiquitin-specific protease 22 (USP22) exhibited aberrant high expression in thyroid cancer tissues and cells. The current study proposed the possible machinery that miR-30d could target and negatively regulate USP22. Additionally, USP22 could enhance the stability of SIRT1 by inducing deubiquitination which consequently contributed to FOXO3a deacetylation-induced PUMA repression. Responding to the gain- or loss-of-function of miR-30d and/or USP22, behaviors of thyroid cancer cells were altered. Accordingly, miR-30d inhibited proliferation and promoted apoptosis of thyroid cancer cells by suppressing USP22 through SIRT1/FOXO3a/PUMA axis. The effects of miR-30d and USP22-mediated SIRT1/FOXO3a/PUMA axis on thyroid tumorigenesis were finally validated in murine models. We ultimately confirmed the anti-proliferative and pro-apoptotic effect of miR-30d via suppressing USP22 through in vivo findings. Conclusively, our findings highlight that the occurrence and progression of thyroid cancer can be suppressed by miR-30d-mediated inhibition of USP22 via the SIRT1/FOXO3a/PUMA axis, which provides a attractive therapeutic target for thyroid cancer treatment.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

Safety and efficacy of HER2 blockade by trastuzumab-based chemotherapy-containing combination strategies in HER2+ gastroesophageal adenocarcinoma

Since completion of the Trastuzumab for Gastric Cancer study, trastuzumab with doublet chemotherapy (a fluoropyrimidine and a platinum) has been the gold-standard first-line therapy for patients with locally advanced unresectable or metastatic human epidermal growth factor receptor 2-positive (HER2+) gastroesophageal adenocarcinoma (GEA). The safety and efficacy of 23 studies of first-line trastuzumab plus doublet chemotherapy, without checkpoint inhibitors (n = 19) or with checkpoint inhibitors (n = 4), conducted in patients with locally advanced unresectable or metastatic HER2+ GEA, including phase II/III, prospective, and retrospective observational studies, were summarized. In studies without checkpoint inhibitors, the median duration of trastuzumab treatment ranged from 19.5 to 39.0 weeks and from 15.3 to 30.0 weeks for chemotherapy. In studies with checkpoint inhibitors, the median duration of pembrolizumab/trastuzumab/chemotherapy was 30 weeks, and 18 weeks for chemotherapy. In studies without checkpoint inhibitors, treatment-emergent adverse events (TEAEs) of grade ≥3 ranged from 32% to 84%. Serious adverse events (SAEs) ranged from 15% to 39%. Adverse events resulting in discontinuation ranged from 0% to 30%. Treatment-related deaths occurred in 0%-9% of patients. In studies with checkpoint inhibitors, TEAEs of grade ≥3 were 57%. SAEs ranged from 31% to 38%. Adverse events resulting in discontinuation ranged from 5% to 24%. Treatment-related deaths occurred in 0%-3% of patients. In studies without checkpoint inhibitors, objective response rate (ORR) ranged from 39% to 82%, median progression-free survival (PFS) from 5.7 to 11.6 months, and median overall survival (OS) from 11.2 to 27.6 months. In studies with checkpoint inhibitors, ORR ranged from 39% to 86%, median PFS from 8.0 to 13.0 months, and median OS from 19.3 to 27.3 months. This review provides a historical benchmark on safety and efficacy of available first-line chemotherapy-based standard of care for patients with locally advanced unresectable or metastatic HER2+ GEA.

Novel Biomarkers of Gastric Adenocarcinoma: Current Research and Future Perspectives

Simple Summary

Gastric cancer is characterized by poor survival rates despite surgery and chemotherapy. Current research focuses on biomarkers to improve diagnosis and prognosis, and to enable targeted treatment strategies. The aim of our review was to give an overview over the wide range of novel biomarkers in gastric cancer. These biomarkers are targets of a specific treatment, such as antibodies against human epidermal growth factor receptor 2. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are vascular endothelial growth factor, programmed cell death protein 1, and Claudin 18.2. There is a vast number of biomarkers based on DNA, RNA, and protein expression, as well as detection of circulating tumor cells and the immune tumor microenvironment.

Abstract

Overall survival of gastric cancer remains low, as patients are often diagnosed with advanced stage disease. In this review, we give an overview of current research on biomarkers in gastric cancer and their implementation in treatment strategies. The HER2-targeting trastuzumab is the first molecular targeted agent approved for gastric cancer treatment. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are VEGF and Claudin 18.2. Expression of MET has been shown to be a negative prognostic factor in gastric cancer. Targeting the PD-1/PD-L1 pathway with immune checkpoint inhibitors has proven efficacy in advanced gastric cancer. Recent technology advances allow the detection of circulating tumor cells that may be used as diagnostic and prognostic indicators and for therapy monitoring in gastric cancer patients. Prognostic molecular subtypes of gastric cancer have been identified using genomic data. In addition, transcriptome profiling has allowed a comprehensive characterization of the immune and stromal microenvironment in gastric cancer and development of novel risk scores. These prognostic and predictive markers highlight the rapidly evolving field of research in gastric cancer, promising improved treatment stratification and identification of molecular targets for individualized treatment in gastric cancer.

Efficacy of trastuzumab and potential risk factors on survival in patients with HER2-positive metastatic gastric cancer

Aim: To evaluate the efficacy of trastuzumab and potential risk factors on survival in patients with HER2-positive metastatic gastric cancer. Methods: We retrospectively included 138 patients who were given trastuzumab-based chemotherapy as first-line treatment and analyzed the relationship between clinical response rates and maintenance treatment status and survival outcomes. Results: In the whole group, the median progression-free survival and overall survival were 10.2 and 16 months, respectively. Clinical response was obtained in 79% of patients. The median overall survival was 16.9 months in follow-up group and 19.0 months in the maintenance group in patients with clinical response. Continuation of maintenance trastuzumab created a significant survival advantage (p = 0.021). Eastern Cooperative Oncology Group performance status 2 (hazard ratio [HR]: 2.02), grade 3 (HR: 1.78) and more than four metastatic lesions (HR: 1.67) were determined as risk factors for death. Conclusion: We recommend the continuation of maintenance trastuzumab in patients with clinical response, but those with identified risk factors may not benefit from treatment because life expectancy may be low.

The role of noncoding RNAs in pituitary adenoma

Pituitary adenomas (PAs) are common cranial tumors that affect the quality of life in patients. Early detection of PA is beneficial for avoiding clinical complications of this disease and increasing the quality of life. Noncoding RNAs, including long noncoding RNA, miRNA and circRNA, regulate protein expression, mostly by inhibiting the translation process. Studies have shown that dysregulation of noncoding RNAs is associated with PA. Hence understanding the expression pattern of noncoding RNAs can be considered a promising method for developing biomarkers. This article reviews data on the expression pattern of dysregulated noncoding RNAs involved in PA. Possible molecular mechanisms by which the dysregulated noncoding RNA could possibly induce PA are also described.

Effectiveness of Trastuzumab in Routine Clinical Practice: A Population-based Study of Patients with HER-2-positive Oesophageal, Gastroesophageal and Gastric Cancer

AIMS

In the pivotal Trastuzumab for Gastric Cancer (ToGA) trial, trastuzumab improved median survival in patients with advanced HER-2-positive gastric and gastroesophageal cancer from 11.1 to 13.8 months; however, its effectiveness in routine clinical practice has not been evaluated. Our objective was to evaluate the uptake and outcomes of trastuzumab in a population-based cohort of patients with oesophageal, gastroesophageal and gastric cancer in Ontario, Canada.

MATERIALS AND METHODS

The Ontario Cancer Registry and linked treatment records were used to identify all patients with oesophageal, gastroesophageal and gastric cancer treated with trastuzumab during 2012-2017. Outcomes were analysed from the time of first trastuzumab cycle and included a primary outcome (survival) and secondary outcomes (uptake, delivery, 30-day hospital admission and 30-day mortality). Trends over the study period and survival were evaluated.

RESULTS

In total, 476 patients with oesophageal, gastroesophageal and gastric cancer received trastuzumab during the study period. The mean age was 62 years, 78% (370/476) were male, and 65% (312/476) had gastric cancer. The annual number of patients receiving trastuzumab increased over the study period (53 in 2012 and 101 in 2017). The median number of cycles of trastuzumab delivered was six. Thirty-day hospital admission and mortality rates were 17% and 4%, respectively. The median overall survival was 282 days (9.3 months).

CONCLUSIONS

The median survival of patients treated with trastuzumab for advanced oesophageal, gastroesophageal and gastric cancer in routine practice is substantially less than that observed in the pivotal clinical trial. Studies of comparative effectiveness using real-world data offer insight into outcomes achieved in routine practice.

Downregulation of miR-140 is Correlated with Poor Prognosis and Progression of Thyroid Cancer

BACKGROUND

The incidence of thyroid cancer is increasing rapidly and there is an urgent need to explore novel therapeutic targets for thyroid cancer. MiR-140 has been reported to affect the progression of various cancers, which makes it possible to play a role in thyroid cancer. This study aimed to investigate the expression and role of miR-140 in thyroid cancer.

METHODS

The expression of miR-140 was investigated by reverse transcription-quantitative polymerase chain reaction (qRT-PCR) in thyroid cancer tissues and cell lines. The prognostic value of miR- 140 in thyroid cancer was evaluated by Kaplan-Meier survival and Cox regression. Moreover, the effects of miR-140 on cell proliferation, migration, and invasion of thyroid cancer were investigated by CCK-8 and Transwell assay.

RESULTS

MiR-140 was downregulated in thyroid cancer tissues and cells, which correlated with TNM stage and lymph node metastasis of patients. Patients with low miR-140 expression had a shorter survival time compared with that in patients with high miR-140 expression. Furthermore, miR-140 acts as an independent factor for the prognosis of thyroid cancer. Overexpression of miR-140 inhibited cell proliferation, migration, and invasion of thyroid cancer.

CONCLUSION

MiR-140 can serve as a potential prognostic factor for patients with thyroid cancer and suppress the progression of thyroid cancer, which provides new insight for the therapeutic target for thyroid cancer.

Review of Survival, Safety, and Clinical Outcomes in HER2+ Metastatic Gastric Cancer Following the Administration of Trastuzumab

BACKGROUND

Therapies targeting human epidermal growth factor receptor 2 (HER2) have become a focus for improving treatment outcomes in patients with gastric cancer. This literature review sought to assesses clinical outcomes, including safety, survival, and treatment outcomes, of patients who received trastuzumab for the treatment of HER2+ metastatic gastric cancer.

METHODS

Searches were conducted in PubMed and Embase to identify observational research studies investigating the clinical outcomes of trastuzumab and combination therapies for the treatment of HER2+ metastatic gastric cancer, published January 1, 2014-August 22, 2019. Article screening was a two-phase process, and the results of each screening level were documented in accordance with PRISMA.

RESULTS

Twenty articles met the selection criteria for data extraction. Studies focused on treatment patterns or survival, safety, and clinical outcomes, as well as the natural history of disease. In the combined HER2+ patient populations included in this review, tumors were located in the stomach (33.7%), gastroesophageal junction (GEJ, 14.2%), unspecific GEJ or stomach (50.3%), or esophagus (1.9%). Studies observed increases in both overall survival and progression-free survival with the use of trastuzumab-based chemotherapy compared with chemotherapy treatment alone. Additionally, trastuzumab-based chemotherapy appeared to improve survival and clinical outcomes regardless of the presence of multi-organ metastases or tumor location.

CONCLUSIONS

Trastuzumab-treated patients have longer survival times than those not treated with trastuzumab and tolerate treatment well, with few serious adverse events. New treatments for second- and subsequent-line therapies would increase regimen options.

MINI-ABSTRACT

The treatment patterns and clinical outcomes observed in this literature review suggest patients treated with trastuzumab have longer survival times compared with chemotherapy treatment alone and tolerate treatment.

Hepatic Arterial Infusion Combined with Systemic Chemotherapy for Patients with Extensive Liver Metastases from Gastric Cancer

Purpose

Liver metastases in patients with gastric cancer often indicate poor prognosis. Once liver metastases are extensive, it is difficult to achieve disease control by using systemic chemotherapy alone. The purpose of this study was to evaluate the effect and safety of hepatic arterial infusion (HAI) combined with systemic chemotherapy on extensive liver metastases from gastric cancer.

Patients and Methods

Between 2012 and 2019, 21 patients with extensive liver metastases from gastric cancer (LMGC) were enrolled in our study. Liver metastases were identified as unresectable and a major factor affecting prognosis mainly based on size and number of intrahepatic lesions. All patients received systemic chemotherapy with S-1 and HAI oxaliplatin plus floxuridine (FUDR).

Results

Liver metastases in 16 patients (76.2%) were evaluated as H3. The overall response rate was 76.2% (9.5% complete response). Intrahepatic and extrahepatic median progression-free survival times were 9.5 and 5.2 months, respectively. Median survival time (MST) was 12.3 months. All patients did not have the toxicity of grade 4. Grade 3 toxic effects included bone marrow suppression (14.3%) and diarrhea (9.5%). The other treatment-related toxicities were mild and reversible.

Conclusion

HAI combined with systemic chemotherapy for extensive LMGC seems to be safe and effective, which achieves a high-local response and may contribute to long survival time for patients.

IntegrinB5 upregulated by HER2 in gastric cancer: a promising biomarker for liver metastasis

BACKGROUND

Liver is the most frequent metastatic site of gastric cancer (GC), especially in patients with HER2 positive GC. Exosomal integrin αvβ5 has been shown to promote liver metastasis (LM), and the cross talk between integrins and HER2 during breast cancer metastasis has been reported. However, whether there's an association between HER2 and integrin αvβ5 (ITGAvB5), and whether their association has predictive value in GC liver metastasis (GCLM) remains unknown.

METHODS

The association between ITGβ5 and HER2 were accessed by RT-PCR, western blot and ELISA. We tested the function of ITGβ5 on HER2 positive GC cells using Transwell assays and scratch assays. Besides, we detect ITGβ5 expression in tumor tissue of GC patients and exosomes derived from advanced GC to analyze the association between HER2 and LM.

RESULTS

In our study, we found that ITGβ5, rather than ITGAV, was highly upregulated by HER2 through PI3K-AKT pathways in HER2 positive GC. Overexpression of ITGβ5 promoted the migration and invasion of HER2 positive GC cells in vitro. ITGβ5 was found to be an independent prognostic factor for GC. Besides, ITGβ5 level was only associated with LM. Detection of exosomal ITGβ5 and HER2 in the serum of GC patients revealed that exosomal ITGβ5 and HER2 levels are in accordance with that in tissue, and exosomal ITGβ5 level was higher in GCLM than other metastasis.

CONCLUSIONS

Our study demonstrated ITGβ5 is regulated and functions in accordance with HER2 in promoting GCLM. Exosomal ITGβ5 levels might be a potential liquid biopsy biomarker for GCLM.

The functions and targets of miR-212 as a potential biomarker of cancer diagnosis and therapy

Cancer is a major health problem worldwide. An increasing number of researchers are studying the diagnosis, therapy and mechanisms underlying the development and progression of cancer. The study of noncoding RNA has attracted a lot of attention in recent years. It was found that frequent alterations of miRNA expression not only have various functions in cancer but also that miRNAs can act as clinical markers of diagnosis, stage and progression of cancer. MiR-212 is an important example of miRNAs involved in cancer. According to recent studies, miR-212 may serve as an oncogene or tumour suppressor by influencing different targets or pathways during the oncogenesis and the development and metastasis of cancer. Its deregulation may serve as a marker for the diagnosis or prognosis of cancer. In addition, it was recently reported that miR-212 was related to the sensitivity or resistance of cancer cells to chemotherapy or radiotherapy. Here, we summarize the current understanding of miR-212 functions in cancer by describing the relevant signalling pathways and targets. The role of miR-212 as a biomarker and its therapeutic potential in cancer is also described. The aim of this review was to identify new methods for the diagnosis and treatment of human cancers.

MicroRNA-212-3p Attenuates Neuropathic Pain via Targeting Sodium Voltage-gated Channel Alpha Subunit 3 (NaV 1.3)

Purpose:

To explore the role and potential mechanism of miR-212-3p in neuropathic pain regulation.

Methods:

Adult male rats were used to establish chronic constriction injury (CCI) model to mimic the neuropathic pain. Then, paw withdrawal threshold (PWT) and paw withdrawal thermal latency (PWL) were determined. The concentrations of interleukin 1 beta (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured with enzyme-linked immune sorbent assay (ELISA) kit and the expression of miR-212-3p was measured by real time quantitative PCR (RTqPCR). Besides, miR-212-3p agomir was intrathecally injected into CCI rats and the expression of key apoptotic proteins was determined by western blot. Furthermore, dual-luciferase reporter assay was used to determine the binding of miR-212-3p and 3’ untranslated regions (3’UTR) of NaV1.3 and the expression levels of NaV1.3 were measured by western blot and RT-qPCR.

Results:

In the CCI group, the PWT and PWL were significantly decreased and IL-1β, IL-6 and TNF-α were increased. miR-212-3p was decreased in response to CCI. The intrathecal injection of miR-212-3p agomir into CCI rats improved the PWT and PWL, decreased the IL-1β, IL-6 and TNF-α, decreased the expression levels of BCL2 associated X, apoptosis regulator (Bax), cleaved caspase-3 and increased the expression levels of BCL2 apoptosis regulator (Bcl-2). The results of dual--luciferase reporter assay showed that miR-212-3p could directly bind with 3’UTR of NaV1.3. The expression of NaV1.3 was up-regulated in CCI rats who were intrathecally injected with miRctrl, whereas it decreased in CCI rats intrathecally injected with miR-212-3p agomir.

Conclusion:

The expression of miR-212a-3p attenuates neuropathic pain by targeting NaV1.3.

MiRNA-12129 Suppresses Cell Proliferation and Block Cell Cycle Progression by Targeting SIRT1 in GASTRIC Cancer

Gastric cancer is the most commonly occurring cancer with a rapidly increasing incidence rate worldwide. The underlying molecular mechanisms of gastric cancer require further investigation. MicroRNAs exhibit tissue sensitivity as tumor biomarkers that play a role by promoting tumor growth as oncogenes or tumor suppressor genes. We evaluated the effects of microRNA-12129 on gastric cancer and identified the underlying mechanisms of microRNA-12129. Quantitative real-time polymerase chain reaction was conducted to determine the expression levels of microRNA-12129 and sirtuin 1 in vivo and in vitro, and Western blot analysis was performed to detect sirtuin 1 at the protein level in gastric cancer cell lines. Cell proliferation and cell cycle progression were detected by Cell Counting Kit-8 assay and flow cytometry analysis, respectively. The potential targets of microRNA-12129 were predicted by bioinformatics analysis. The targets of microRNA-12129 were confirmed by luciferase reporter assay and rescue assay. We found that microRNA-12129 was downregulated in gastric cancer tissues and gastric cancer cell lines and was significantly associated with the prognosis of patients with gastric cancer. In addition, microRNA-12129 overexpression suppressed tumor cell proliferation and blocked cell cycle progression. Bioinformatics analysis and luciferase reporter assay suggested that sirtuin 1 was a target of microRNA-12129, and sirtuin 1 expression was negatively related to microRNA-12129. Restoration of sirtuin 1 partly reduced the inhibition of cell proliferation and cell cycle progression induced by microRNA-144. Our results collectively suggested that microRNA-12129 suppressed cell proliferation and cell cycle progression in gastric cancer by targeting sirtuin 1. These findings indicated that manipulation of microRNA-12129 expression could help develop a novel therapeutic strategy for gastric cancer.

Inhibition of sirtuin 1 deacetylase by miR-211-5p provides a mechanism for the induction of cell death in breast cancer cells

Sirtuin 1 is one of the regulators of cell growth and survival and its inhibition is suggested as a suitable mechanism to overcome breast cancer development. In this study we explored the role of miR-211-5p in SIRT1/p53 pathway and its influence on breast cancer cell viability and apoptosis. Cells were transfected with miR-211-5p mimic and inhibitor to modulate cellular miR-211-5p levels in breast cancer cell lines, MDA-MB-231 and MCF-7. Gene expression of miR-211-5p and SIRT1 were measured with real-time PCR. SIRT1 protein level and the acetylation of p53 as well as SIRT1 activity were evaluated by Western blotting and fluorometry, respectively. In order to explore the direct attachment of miR-211-5p to the 3'-UTR of SIRT1 mRNA, luciferase reporter assay was applied. Cell viability in response to miR-211-5p was studied by MTT assay and apoptosis was assessed by annexin V labeling followed by flow cytometry. Results showed that SIRT1 gene and protein expression were inhibited by miR-211-5p and the 3'-UTR of SIRT1 was found to be directly targeted by miR-211-5p. Inhibition of SIRT1 expression resulted in its reduced activity. Up-regulation of miR-211-5p was also followed by a significant decline in the acetylation status of p53 which was associated with remarkable decreased cell viability and induction of apoptosis in breast cancer cells. Antisense oligonucleotide of miR-211-5p acted as its inhibitor and exerted opposite effects both on SIRT1 expression and cell apoptosis. In conclusion, inhibition of SIRT1 by miR-211-5p could effectively reduce breast cancer cell survival and cause cell death and therefore might be considered a seemly mechanism for designing anticancer therapies.

Aging, Melatonin, and the Pro- and Anti-Inflammatory Networks

Aging and various age-related diseases are associated with reductions in melatonin secretion, proinflammatory changes in the immune system, a deteriorating circadian system, and reductions in sirtuin-1 (SIRT1) activity. In non-tumor cells, several effects of melatonin are abolished by inhibiting SIRT1, indicating mediation by SIRT1. Melatonin is, in addition to its circadian and antioxidant roles, an immune stimulatory agent. However, it can act as either a pro- or anti-inflammatory regulator in a context-dependent way. Melatonin can stimulate the release of proinflammatory cytokines and other mediators, but also, under different conditions, it can suppress inflammation-promoting processes such as NO release, activation of cyclooxygenase-2, inflammasome NLRP3, gasdermin D, toll-like receptor-4 and mTOR signaling, and cytokine release by SASP (senescence-associated secretory phenotype), and amyloid-β toxicity. It also activates processes in an anti-inflammatory network, in which SIRT1 activation, upregulation of Nrf2 and downregulation of NF-κB, and release of the anti-inflammatory cytokines IL-4 and IL-10 are involved. A perhaps crucial action may be the promotion of macrophage or microglia polarization in favor of the anti-inflammatory phenotype M2. In addition, many factors of the pro- and anti-inflammatory networks are subject to regulation by microRNAs that either target mRNAs of the respective factors or upregulate them by targeting mRNAs of their inhibitor proteins.

SIRT1 in Secretory Organ Cancer

Mammalian silent information regulator 1 (SIRT1) is reported to play a role in cancers of the secretory organs, including thyroid, pancreatic endocrine, and ovarian tumors [1, 2, 3, 4]. A recent meta-analysis conducted on 37 selected studies of human cancers analyzed the correlations of overall survival (OS), disease-free survival (DFS) and relapse-free survival (RFS) with SIRT1 expression [5]. This study reported that SIRT1 overexpression was associated with a worse OS in liver and lung cancers, while it was not correlated with OS in breast cancer, colorectal cancer, or gastric carcinoma. Collectively, the meta-analysis revealed that an unfavorable OS was associated with SIRT1 expression for solid malignancies. Given the growing importance of this class of lysine/histone deacetylases in human endocrine malignancies, a rational and focused literature assessment is desirable in light of future clinical translations.