FOXO1 Suppression is a Determinant of Acquired Lapatinib-Resistance in HER2-Positive Gastric Cancer Cells Through MET Upregulation

The novel BCL-2/BCL-XL inhibitor APG-1252-mediated cleavage of GSDME enhances the antitumor efficacy of HER2-targeted therapy in HER2-positive gastric cancer

HER2-positive gastric cancer has a poor prognosis, with a high incidence of drug resistance and a lack of effective treatments for drug-resistant patients. The exploration of the mechanism of resistance to HER2-targeted therapy in HER2-positive gastric cancer and the identification of effective strategies to reverse it are urgently needed. In this study, we found that HER2-targeted agents upregulated the expression of GSDME and that the overexpression of GSDME attenuated the sensitivity of HER2-targeted agents. Furthermore, we observed that the BCL-2/BCL-XL inhibitor APG-1252 plus lapatinib promoted GSDME-mediated pyroptosis and exhibited remarkable antitumor activity both in vitro and in vivo. Mechanistically, APG-1252 combined with lapatinib synergistically induced GSDME-mediated pyroptosis in HER2-positive gastric cancer by activating caspase-dependent pathways and blocking the phospho-AKT/GSK-3β/MCL-1 signaling pathway. Our data indicated that the combination of lapatinib and APG-1252 had a synergistic antitumor effect on HER2-positive gastric cancer through the induction of caspase-3/GSDME-mediated apoptosis and pyroptosis.

FoxO1 Deficiency in Monocytic Myeloid-Derived Suppressor Cells Exacerbates B Cell Dysfunction in Systemic Lupus Erythematosus

OBJECTIVE

Myeloid-derived suppressor cells (MDSCs) contribute to the pathogenesis of systemic lupus erythematosus (SLE), in part due to promoting the survival of plasma cells. FoxO1 expression in monocytic MDSCs (M-MDSCs) exhibits a negative correlation with the SLE Disease Activity Index score. This study aimed to investigate the hypothesis that M-MDSC-specific FoxO1 deficiency enhances aberrant B cell function in aggressive SLE.

METHODS

We used GEO data sets and clinical cohorts to verify the clinical significance of FoxO1 expression and circulating M-MDSCs. Using Cre-LoxP technology, we generated myeloid FoxO1 deficiency mice (mFoxO1-/-) to establish murine lupus-prone models. The transcriptional stage was assessed by integrating chromatin immunoprecipitation (ChIP)-sequencing with transcriptomic analysis, luciferase reporter assay, and ChIP-quantitative polymerase chain reaction. Methylated RNA immunoprecipitation sequencing, RNA sequencing, and CRISPR-dCas9 were used to identify N6-adenosine methylation (m6A) modification. In vitro B cell coculture experiments, capmatinib intragastric administration, m6A-modulated MDSCs adoptive transfer, and sample validation of patients with SLE were performed to determine the role of FoxO1 on M-MDSCs dysregulation during B cell autoreacted with SLE.

RESULTS

We present evidence that low FoxO1 is predominantly expressed in M-MDSCs in both patients with SLE and lupus mice, and mice with myeloid FoxO1 deficiency (mFoxO1-/-) are more prone to B cell dysfunction. Mechanically, FoxO1 inhibits mesenchymal-epithelial transition factor protein (Met) transcription by binding to the promoter region. M-MDSCs FoxO1 deficiency blocks the Met/cyclooxygenase2/prostaglandin E2 secretion pathway, promoting B cell proliferation and hyperactivation. The Met antagonist capmatinib effectively mitigates lupus exacerbation. Furthermore, alkB homolog 5 (ALKBH5) targeting catalyzes m6A modification on FoxO1 messenger RNA in coding sequences and 3' untranslated regions. The up-regulation of FoxO1 mediated by ALKBH5 overexpression in M-MDSCs improves lupus progression. Finally, these correlations were confirmed in untreated patients with SLE.

CONCLUSION

Our findings indicate that effective inhibition of B cells mediated by the ALKBH5/FoxO1/Met axis in M-MDSCs could offer a novel therapeutic approach to manage SLE.

HER2-targeted therapies beyond breast cancer - an update

The receptor tyrosine-kinase HER2 (also known as ErbB2) is a well-established therapeutic target in patients with breast or gastric cancer selected on the basis of HER2 overexpression on immunohistochemistry and/or ERBB2 amplification on in situ hybridization. With advances in cancer molecular profiling and increased implementation of precision medicine approaches into oncology practice, actionable HER2 alterations in solid tumours have expanded to include ERBB2 mutations in addition to traditional HER2 overexpression and ERBB2 amplification. These various HER2 alterations can be found in solid tumour types beyond breast and gastric cancer, although few HER2-targeted therapeutic options have been established for the other tumour types. Nevertheless, during the 5 years since our previous Review on this topic was published in this journal, obvious and fruitful progress in the development of HER2-targeted therapies has been made, including new disease indications, innovative drugs with diverse mechanisms of action and novel frameworks for approval by regulatory authorities. These advances have culminated in the recent histology-agnostic approval of the anti-HER2 antibody-drug conjugate trastuzumab deruxtecan for patients with HER2-overexpressing solid tumours. In this new Review, we provide an update on the current development landscape of HER2-targeted therapies beyond breast cancer, as well as anticipated future HER2-directed treatment strategies to overcome resistance and thereby improve efficacy and patient outcomes.

Resistance to Anti-HER2 Therapies in Gastrointestinal Malignancies

Human epidermal growth factor 2 (HER2) is a tyrosine kinase receptor that interacts with multiple signaling pathways related to cellular growth and proliferation. Overexpression or amplification of HER2 is linked to various malignancies, and there have been decades of research dedicated to targeting HER2. Despite the landmark ToGA trial, progress in HER2-positive gastrointestinal malignancies has been hampered by drug resistance. This review examines current HER2 expression patterns and therapies for gastroesophageal, colorectal, biliary tract, and small bowel cancers, while dissecting potential resistance mechanisms that limit treatment effectiveness.

Characterization of MET Alterations in 37 Gastroesophageal Cancer Cell Lines for MET-Targeted Therapy

Capmatinib and savolitinib, selective MET inhibitors, are widely used to treat various MET-positive cancers. In this study, we aimed to determine the effects of these inhibitors on MET-amplified gastric cancer (GC) cells. Methods: After screening 37 GC cell lines, the following cell lines were found to be MET-positive with copy number variation >10: SNU-620, ESO51, MKN-45, SNU-5, and OE33 cell lines. Next, we assessed the cytotoxic response of these cell lines to capmatinib or savolitinib alone using cell counting kit-8 and clonogenic cell survival assays. Western blotting was performed to assess the effects of capmatinib and savolitinib on the MET signaling pathway. Xenograft studies were performed to evaluate the in vivo therapeutic efficacy of savolitinib in MKN-45 cells. Savolitinib and capmatinib exerted anti-proliferative effects on MET-amplified GC cell lines in a dose-dependent manner. Savolitinib inhibited the phosphorylation of MET and downstream signaling pathways, such as the protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) pathways, in MET-amplified GC cells. Additionally, savolitinib significantly decreased the number of colonies formed on the soft agar and exerted dose-dependent anti-tumor effects in an MKN-45 GC cell xenograft model. Furthermore, a combination of trastuzumab and capmatinib exhibited enhanced inhibition of AKT and ERK activation in human epidermal growth factor receptor-2 (HER2)- and MET-positive OE33 cells. Targeting MET with savolitinib and capmatinib efficiently suppressed the growth of MET-amplified GC cells. Moreover, these MET inhibitors exerted synergistic effects with trastuzumab on HER2- and MET-amplified GC cells.

The FOXO1/G6PC axis promotes gastric cancer progression and mediates 5-fluorouracil resistance by targeting the PI3K/AKT/mTOR signaling pathway

Gastric cancer (GC) is a prevalent malignancy of the digestive system. Distant metastasis and chemotherapy resistance are the crucial obstacles to prognosis in GC. Recent research has discovered that the glucose-6-phosphatase catalytic subunit (G6PC) plays an important role in tumor malignant development. However, little evidence has highlighted its role in GC. Herein, through a comprehensive analysis including profiling of tissue samples and functional validation in vivo and in vitro, we identify G6PC as a crucial factor in GC tumorigenesis. Importantly, we found that the FOXO1/G6PC axis could accelerate GC cell proliferation, metastasis, and 5-Fluorouracil (5-FU) resistance by targeting the PI3K/AKT/mTOR signaling pathway, implicating that as a prospective therapeutic approach in GC.

Up-regulation of microRNA-183 reduces FOXO1 expression in gastric cancer patients with Helicobacter pylori infection

The aim of the study is to detect the expression of FOXO1 mRNA and protein in samples from gastric cancer patients with Helicobacter pylori (H. pylori) infection, and to investigate the relationship between FOXO1 expression and miR-183 expression. Twenty-six gastric cancer patients with H. pylori infection and 26 gastric cancer patients without H. pylori infection were included into experimental group and control group, respectively. Tumor tissues and peripheral blood were collected from all subjects. QRT-PCR was used to determine the expression of miRNA and mRNA. Western blotting was carried out to measure protein expression. Dual luciferase reporter assay was used to identify direct interaction between miRNA and 3'-UTR of mRNA. Cell proliferation was examined by CCK-8 assay. FOXO1 mRNA and protein expression was down-regulated in gastric cancer patients, being possibly related to H. pylori infection. The expression of miR-183 in tumor tissues and serum from gastric cancer patients with H. pylori infection was elevated, and probably regulated the expression of FOXO1 by direct targeting. Stimulation by H. pylori up-regulated the expression of miR-183 in gastric cancer AGS cells, and reduced the levels of FOXO1 mRNA and protein. Inhibition of miR-183 elevated the expression of FOXO1 and suppressed the proliferation of AGS cells. The present study demonstrates that the expression of FOXO1 in tumor tissues and blood from gastric cancer patients with H. pylori infection is significantly down-regulated, and may be related to the up-regulation of miR-183. H. pylori may regulate FOXO1 expression through miR-183 to affect the pathological process of gastric cancer.

Targeted and Immunotherapy Approaches in HER2-Positive Gastric and Gastroesophageal Junction Adenocarcinoma: A New Era

HER2-targeted therapy with the HER2 monoclonal antibody trastuzumab has achieved impressive outcomes in the first-line settings of patients with advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma overexpressing HER2. However, considering that a substantial proportion of those patients eventually relapses, as well as the relatively limited performance of those agents in second-line settings, a deeper understanding of resistance mechanisms is needed for enhanced guidance for patients' therapeutic selection in the second-line setting and beyond. In this review, we highlight trastuzumab's (HER2-targeting agent) performance in patients with gastric or GEJ cancer, with insight into mechanisms of resistance. We also discuss the new integration of PD-1 inhibitor pembrolizumab into the trastuzumab for gastric cancer frontline regimen, the latest addition of trastuzumab deruxtecan to the treatment armamentarium, and the potential of pipeline HER2-targeting approaches and combinations in patients with gastric or GEJ adenocarcinoma.

The FOXO family of transcription factors: key molecular players in gastric cancer

Gastric cancer (GC) is the fifth most frequently diagnosed cancer worldwide and the third leading cause of cancer-related death with an oncological origin. Despite its decline in incidence and mortality in recent years, GC remains a global public problem that seriously threatens patients' health and lives. The forkhead box O proteins (FOXOs) are a family of evolutionarily conserved transcription factors (TFs) with crucial roles in cell fate decisions. In mammals, the FOXO family consists of four members FOXO1, 3a, 4, and 6. FOXOs play crucial roles in a variety of biological processes, such as development, metabolism, and stem cell maintenance, by regulating the expression of their target genes in space and time. An accumulating amount of evidence has shown that the dysregulation of FOXOs is involved in GC progression by affecting multiple cellular processes, including proliferation, apoptosis, invasion, metastasis, cell cycle progression, carcinogenesis, and resistance to chemotherapeutic drugs. In this review, we systematically summarize the recent findings on the regulatory mechanisms of FOXO family expression and activity and elucidate its roles in GC progression. Moreover, we also highlight the clinical implications of FOXOs in GC treatment.

Overcoming resistance to targeted therapy using MET inhibitors in solid cancers: evidence from preclinical and clinical studies

Targeted therapy is a hallmark of cancer treatment that has changed the landscape of cancer management and enabled a personalized treatment approach. Nevertheless, the development of cancer resistance is a major challenge that is currently threatening the effective utilization of targeted therapies. The hepatocyte growth factor receptor, MET, is a receptor tyrosine kinase known for its oncogenic activity and tumorigenic potential. MET is a well-known driver of cancer resistance. A growing body of evidence revealed a major role of MET in mediating acquired resistance to several classes of targeted therapies. Deregulations of MET commonly associated with the development of cancer resistance include gene amplification, overexpression, autocrine activation, and crosstalk with other signaling pathways. Small-molecule tyrosine kinase inhibitors of MET are currently approved for the treatment of different solid cancers. This review summarizes the current evidence regarding MET-mediated cancer resistance toward targeted therapies. The molecular mechanisms associated with resistance are described along with findings from preclinical and clinical studies on using MET inhibitors to restore the anticancer activity of targeted therapies for the treatment of solid tumors.

Diverse roles of FOXO family members in gastric cancer

Gastric cancer (GC) is the fifth most diagnosed cancer and the third leading cause of cancer-related death worldwide. Although progress has been made in diagnosis, surgical resection, systemic chemotherapy, and immunotherapy, patients with GC still have a poor prognosis. The overall 5-year survival rate in patients with advanced GC is less than 5%. The FOXO subfamily, of the forkhead box family of transcription factors, consists of four members, FOXO1, FOXO3, FOXO4, and FOXO6. This subfamily plays an important role in many cellular processes, such as cell cycle, cell growth, apoptosis, autophagy, stress resistance, protection from aggregate toxicity, DNA repair, tumor suppression, and metabolism, in both normal tissue and malignant tumors. Various studies support a role for FOXOs as tumor suppressors based on their ability to inhibit angiogenesis and metastasis, and promote apoptosis, yet several other studies have shown that FOXOs might also promote tumor progression in certain circumstances. To elucidate the diverse roles of FOXOs in GC, this article systematically reviews the cellular functions of FOXOs in GC to determine potential therapeutic targets and treatment strategies for patients with GC.

Current therapeutic options for gastric adenocarcinoma

Gastric cancer inflicts significant health issues globally despite its declining incidence. The disease is known to be diagnosed at its advanced stages also corresponding with a poor prognosis for patients. The integral therapeutic choices to cure advanced gastric cancer have progressed swiftly in modern days. The preface of molecularly targeted therapeutic techniques would potentiate the personalized approach depending on patient-specific and tumor-specific features, exasperating the advantages of chemotherapy. Here we have reviewed the modern therapeutics such as immune therapy, chemotherapy, m-RNA based therapeutics, alongside evaluating the influence of age, sex and comorbidities-like factors on the occurrence of gastric cancer. Gastric cancer therapy consolidated target agents comprising inhibitors of programmed death-1(PD-1), human epidermal growth factor receptor 2 (HER2), mRNA, and epidermal growth factor receptor (EPGF). A combination of trastuzumab to platinum-mediated chemotherapy evolved has a typical front-line therapy in advanced gastric cancer. An attempt has been made to epitomize the contemporary-modern research on targeted therapy for advanced gastric cancer.

HER2-targeted therapies in gastric cancer

Molecular targeted therapy of cancer has always been the focus of clinicians. Among those therapeutic targets, the human epidermal growth factor receptor-2 (HER-2) signaling pathway is one of the most popular targets for translational research in cancer. However, unlike prospect in breast cancer, HER-2 inhibitor trastuzumab is the only molecular targeted drug approved by US Food and Drug Administration (FDA) for the first-line treatment of HER-2 positive advanced gastric cancer. On this basis, a variety of novel HER2- targeted drugs for gastric cancer are under development, and related clinical researches are in full swing, including small molecular kinase inhibitors (e.g., afatinib, neratinib, pyrotinib), antibody-drug conjugates (e.g., DS-8201a, RC48-ADC) and other novel therapies (e.g., ZW25, CAR-T, BVAC-B). In this study, we will summarize the recent advances in anti-HER-2 agents, potential mechanisms of resistance to HER2-targeted therapy in HER2-positive gastric cancer. We will also discuss the future prospects of potential strategies to overcome anti-HER-2 resistance and development of novel anti-HER-2 approaches for the treatment of HER2-positive gastric cancer patients.

Fertility preservation in women with ovarian cancer: Finding new pathways: A case-control study

Background

Surgery and chemotherapy are the two most common treatments for cancers, including ovarian cancer. Although most ovarian cancers occur over the age of 45 yr, it may involve younger women and affect their reproductive ability.

Objective

To assess the expression of Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), Forkhead Box O1 (FOXO1), and miR-340 genes in the ovarian cancer tissues as well as ovarian cancer cell lines.

Materials and Methods

In this case-control study, 30 ovarian cancer samples (with the average age of 37 ± 2.5 years) coupled with their non-tumor marginal tissue (as a control) were collected. Proliferated cell lines were treated with several concentrations of cisplatin, and the half maximal inhibitory concentration (IC50) of cisplatin was quantified by MTT-assay. After RNA extraction, cDNA synthesis and qRT-PCR were done. Finally, the results were analyzed.

Results

While the expression levels of miR-340 and FOXO1 genes in tumor samples displayed a significant reduction (p ≤ 0.001), the LGR5 gene presented a significant increase in expression (p ≤ 0.0001). However, conversely, the expression levels of miR-340 and FOXO1 genes in cisplatin-sensitive cell lines, after 24, 48, and 72 hr of cisplatin treatment, indicated a significant increase (p ≤ 0.001) while the expression of LGR5 gene showed a significant decrease in the cisplatin-sensitive cell line (p < 0.05).

Conclusion

The LGR5, FOXO1, and miR-340 genes can be targeted for early diagnosis and more accurate treatment of ovarian cancer and may prevent some of the ovarian cancer complications such as infertility.

VGLL1 phosphorylation and activation promotes gastric cancer malignancy via TGF-β/ERK/RSK2 signaling

We previously reported that vestigial-like 1 (VGLL1), a cofactor of transcriptional enhanced associate domain 4 (TEAD4), is transcriptionally regulated by PI3K and β-catenin signaling and is involved in gastric cancer malignancy. However, the precise mechanism underlying the regulation of VGLL1 activation remains unknown. Therefore, we aimed to investigate the molecular mechanism underlying the transforming growth factor-β (TGF-β)-mediated activation of VGLL1 and the VGLL1-TEAD4 interaction in gastric cancer cells. We showed that TGF-β enhanced VGLL1 phosphorylation and that this phosphorylated VGLL1 functioned as a transcription cofactor of TEAD4 in NUGC3 cells. TGF-β also increased the phosphorylation of ERK and ribosomal S6 kinase 2 (RSK2) in NUGC3 cells, thereby triggering the translocation of phosphorylated RSK2 to the nucleus. Site-directed mutagenesis and immunoprecipitation experiments revealed that RSK2 phosphorylated VGLL1 at S84 in the presence of TGF-β. Mutation of VGLL1 at S84 suppressed VGLL1-TEAD4 binding and the subsequent transcriptional activation of matrix metalloprotease 9 (MMP9). Moreover, VGLL1 peptide containing S84 suppressed the TGF-β-induced MMP9 expression and reduced the invasion and proliferation of gastric cancer cells, whereas VGLL1 peptide containing S84A did not. Furthermore, suppression of expression or activation of VGLL1 enhances the therapeutic effects of lapatinib. Collectively, these results indicate that VGLL1 phosphorylation via TGF-β/ERK/RSK2 signaling plays a crucial role in MMP9-mediated malignancy of gastric cancer. In addition, our study highlights the therapeutic potential of the peptide containing VGLL1 S84 for the treatment of gastric cancer.

FOXO transcription factor family in cancer and metastasis

Forkhead box O (FOXO) transcription factors regulate diverse biological processes, affecting development, metabolism, stem cell maintenance and longevity. They have also been increasingly recognised as tumour suppressors through their ability to regulate genes essential for cell proliferation, cell death, senescence, angiogenesis, cell migration and metastasis. Mechanistically, FOXO proteins serve as key connection points to allow diverse proliferative, nutrient and stress signals to converge and integrate with distinct gene networks to control cell fate, metabolism and cancer development. In consequence, deregulation of FOXO expression and function can promote genetic disorders, metabolic diseases, deregulated ageing and cancer. Metastasis is the process by which cancer cells spread from the primary tumour often via the bloodstream or the lymphatic system and is the major cause of cancer death. The regulation and deregulation of FOXO transcription factors occur predominantly at the post-transcriptional and post-translational levels mediated by regulatory non-coding RNAs, their interactions with other protein partners and co-factors and a combination of post-translational modifications (PTMs), including phosphorylation, acetylation, methylation and ubiquitination. This review discusses the role and regulation of FOXO proteins in tumour initiation and progression, with a particular emphasis on cancer metastasis. An understanding of how signalling networks integrate with the FOXO transcription factors to modulate their developmental, metabolic and tumour-suppressive functions in normal tissues and in cancer will offer a new perspective on tumorigenesis and metastasis, and open up therapeutic opportunities for malignant diseases.

In vitro and in vivo Anti-Tumor Effects of Pan-HER Inhibitor Varlitinib on Cholangiocarcinoma Cell Lines

Background

Cholangiocarcinoma (CCA) is a slowly progressing but highly aggressive malignancy. Targeting the HER protein family represents a potential therapeutic strategy for CCA treatment. The pan-HER inhibitor varlitinib is being developed for the treatment of breast cancer, gastric cancer, and biliary tract cancer, which includes CCA. This study aims to evaluate the anti-tumor effect of varlitinib on CCA using both in vitro and in vivo models.

Materials and Methods

HER family expression profiles and the cytotoxic activity of varlitinib were determined in CCA cell lines (KKU-214, KKU-213, KKU-156 and KKU-100) and cholangiocyte (MMNK-1). Anti-proliferation and apoptosis induction were examined in KKU-214 and KKU-100 cell lines. A combination of varlitinib with PI3K inhibitor, BKM-120, was explored for efficacy in the KKU-100 cell line. In addition, the anti-tumor activity of varlitinib on CCA and the key metabolites were evaluated in tumor tissues from CCA xenograft model.

Results

Elevated expressions of EGFR and HER2 were observed in KKU-214 and KKU-100 cells and varlitinib can suppress CCA cell growth in the micromolar range. Varlitinib inhibits cell proliferation and enhances cell death via the suppression of Akt and Erk1/2 activity in the KKU-214 cell line. While KKU-100 cells showed a poor response to varlitinib, a combination of varlitinib with BKM-120 improved anti-tumor activity. Varlitinib can significantly suppress tumor growth in the CCA xenograft model after oral administration for 15 days without noticeable toxicity, and aspartate can be the key metabolite to correlate with varlitinib response.

Conclusion

Our study indicates that varlitinib is a promising therapeutic agent for CCA treatment via the inhibition of EGFR/HER2. The anti-tumor effect of varlitinib on CCA also showed synergism in combination with PI3K inhibition. Aspartate metabolite level was correlated with varlitinib response. Combination of varlitinib with targeted drug or cytotoxic drug was recommended.

Machine Learning-Guided Prediction of Antigen-Reactive In Silico Clonotypes Based on Changes in Clonal Abundance through Bio-Panning

c-Met is a promising target in cancer therapy for its intrinsic oncogenic properties. However, there are currently no c-Met-specific inhibitors available in the clinic. Antibodies blocking the interaction with its only known ligand, hepatocyte growth factor, and/or inducing receptor internalization have been clinically tested. To explore other therapeutic antibody mechanisms like Fc-mediated effector function, bispecific T cell engagement, and chimeric antigen T cell receptors, a diverse panel of antibodies is essential. We prepared a chicken immune scFv library, performed four rounds of bio-panning, obtained 641 clones using a high-throughput clonal retrieval system (TrueRepertoireTM, TR), and found 149 antigen-reactive scFv clones. We also prepared phagemid DNA before the start of bio-panning (round 0) and, after each round of bio-panning (round 1-4), performed next-generation sequencing of these five sets of phagemid DNA, and identified 860,207 HCDR3 clonotypes and 443,292 LCDR3 clonotypes along with their clonal abundance data. We then established a TR data set consisting of antigen reactivity for scFv clones found in TR analysis and the clonal abundance of their HCDR3 and LCDR3 clonotypes in five sets of phagemid DNA. Using the TR data set, a random forest machine learning algorithm was trained to predict the binding properties of in silico HCDR3 and LCDR3 clonotypes. Subsequently, we synthesized 40 HCDR3 and 40 LCDR3 clonotypes predicted to be antigen reactive (AR) and constructed a phage-displayed scFv library called the AR library. In parallel, we also prepared an antigen non-reactive (NR) library using 10 HCDR3 and 10 LCDR3 clonotypes predicted to be NR. After a single round of bio-panning, we screened 96 randomly-selected phage clones from the AR library and found out 14 AR scFv clones consisting of 5 HCDR3 and 11 LCDR3 AR clonotypes. We also screened 96 randomly-selected phage clones from the NR library, but did not identify any AR clones. In summary, machine learning algorithms can provide a method for identifying AR antibodies, which allows for the characterization of diverse antibody libraries inaccessible by traditional methods.

Identification of lapatinib sensitivity-related genes by integrative functional module analysis

Background

Globally, gastric carcinoma (GC) is one of the most commonly encountered malignancies and is the second highest contributor to cancer mortality. Lapatinib is a potent, orally-bioavailable small-molecule inhibitor of both epidermal growth factor receptor and human epidermal growth factor receptor-2 tyrosine kinases, and is administered to treat GC. However, a large proportion of patients either develop resistance to or do not respond to lapatinib, often because the treatment activates alternative signaling pathways. It is, therefore, vital to identify the key pathways which mediate resistance to lapatinib treatment.

Methods

The lapatinib sensitivity-related genes were extracted from the CellMiner database (version 2.2) using “NCI-60 Analysis Tools”. The differentially expressed genes (DEGs) in gastric cancer were derived from The Cancer Genome Atlas (TCGA) database, the protein-protein interaction (PPI) network was derived from the Human Protein Reference Database (HPRD), and the Database for Annotation, Visualization and Integrated Discovery (DAVID) facilitated the functional analysis. The cell function was tested by CCK-8 cell viability assay, colony formation assay, acridine orange/ethidium bromide (AO/EB) staining, and Transwell assay.

Results

The functional linkage networks of lapatinib sensitivity were constructed. Two modules were identified, and pathway analysis indicated that these modules were involved in several pathways, including the neuroactive ligand-receptor interaction network and the Rap1 signaling pathway. Finally, the breast cancer anti-estrogen resistance 1 (BCAR1) gene was selected for further study with lapatinib-resistant SUN216 cells (SUN216/LR). We found the expression of BCAR1 was upregulated in SUN216/LR cells compared to SUN216 cells. The IC50 of lapatinib in SUN216/LR cells was reduced upon BCAR1 knockdown, as measured by a CCK-8 assay. A clonogenic assay showed fewer SUN216/LR colonies with BCAR1 knockdown and lapatinib treatment.

Conclusions

In brief, we efficiently identified those crucial modules highly related to lapatinib sensitivity in GC by using a topological network method. BCAR1 was identified as a potentially critical gene that plays a role in lapatinib sensitivity, and experiments confirmed that BCAR1 might contribute to lapatinib resistance in GC. These results provide further insight into the molecular basis of lapatinib sensitivity and may offer novel strategies for the future treatment of GC.

Caveolin-1 Promotes Chemoresistance of Gastric Cancer Cells to Cisplatin by Activating WNT/β-Catenin Pathway

Drug resistance is a major challenge for chemotherapy in treating human gastric cancer (GC), as the underlying molecular mechanism of chemoresistance in GC remains unknown. Caveolin-1 (Cav-1) is a scaffold protein of plasma membrane caveolae that acts as a tumor modulator by interacting with several cell signals. In this research, we showed that the survival rate of GC cells to cisplatin (CDDP) increased in the presence of Cav-1. Moreover, Cav-1 overexpression inhibited cisplatin-induced apoptosis and improved the survival rate of GC cells. Cav-1 overexpression and knock-down experiments indicated that Cav-1 expression stimulated wingless-type MMTV integration site (WNTs) pathway through the phosphorylation of LRP6 and dephosphorylation of β-catenin. Cav-1 was positively associated with the increase of WNT downstream target gene Met, which led to the activation of HER2 signaling. Moreover, our results demonstrated that the expression of Cav-1 and Met were positively associated with the resistance of GC cells to cisplatin. Collectively, Cav-1 enhances the cisplatin-resistance of GC cells by activating the WNT signaling pathway and Met-HER2 crosstalk. Understanding the role of Cav-1 in the chemoresistance of GC would help to develop novel therapies for a better treatment outcome of GC patients.

The efficacy and safety of onartuzumab in patients with solid cancers: A meta-analysis of randomized trials

Background

Onartuzumab, a humanized monovalent monoclonal antibody to the MET protein, has been tested in various cancers. We conducted a meta-analysis of randomized phase II and III clinical trials to investigate the efficacy and safety of onartuzumab in solid cancers.

Methods

We searched PubMed, PMC, EMBASE, and the Cochrane library databases. We included randomized phase II or III trials that evaluated the additional benefits of onartuzumab in comparison with the standard treatments. Data on progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were pooled and analyzed.

Results

From nine studies, a total of 2,138 patients were included in the meta-analysis. The addition of onartuzumab to the standard treatment resulted in no improvement of PFS (hazard ratio (HR) = 1.00 [95% confidence interval (CI), 0.90-1.11], P = 0.93) and OS (HR = 1.08 [95% CI, 0.94-1.23], P = 0.29). In the subgroup analysis with patients with non-small-cell lung cancer (NSCLC), onartuzumab was not associated with a significant improvement of OS (HR = 1.12 [95% CI, 0.93-1.34], P = 0.23) and PFS (HR = 1.05 [95% CI, 0.91-1.21], P = 0.52). With respect to AEs, onartuzumab increased the incidence of hypoalbuminemia (odds ratio (OR) = 14.8 [95% CI, 3.49-62.71], P < 0.001), peripheral edema (OR = 6.52 [95% CI, 3.60-11.81], P < 0.001), neutropenia (OR = 1.36 [95% CI, 1.03-1.79], P = 0.03), thrombocytopenia (OR = 1.98 [95% CI, 1.03-3.81], P = 0.04), and venous thrombotic events (OR = 3.05 [95% CI, 1.39-6.71], P = 0.006).

Conclusion

This meta-analysis indicates that the addition of onartuzumab to the standard treatments had no definite survival benefit with increased severe toxicities in patients with solid cancer.

The Use of Epidermal Growth Factor Receptor Type 2-Targeting Tyrosine Kinase Inhibitors in the Management of Epidermal Growth Factor Receptor Type 2-Positive Gastric Cancer: A Narrative Review

Gastric cancer (GC), including gastroesophageal junction cancer (GEJC), continues to be one of the most frequently diagnosed neoplasms globally. Moreover, GC/GEJC is a principal cause of neoplasm-related fatalities. Early-stage GC/GEJC has a favorable five-year overall survival (OS) rate with surgical resection. However, the vast majority of patients present with advanced inoperable or metastatic disease with a very unfavorable five-year OS rate. Such patients are left with very limited therapeutic options, such as systemic chemotherapy, targeted therapy, and immunotherapy, all of which can be performed as monotherapy or in various combinations. The molecular profiling of GC has revealed several personalized therapeutic vulnerabilities, one of which is the expression of epidermal growth factor receptor type 2 (EGFR2, also known as HER2). HER2 overexpression or amplification is present in a fair subset of patients with GC/GEJC and has been shown to correlate with poor clinicopathological prognostic outcomes. Generally, treatment schemes to tackle HER2 in HER2-positive GC/GEJC comprise the use of anti-HER2 monoclonal antibodies or HER2-targeting tyrosine kinase inhibitors (TKIs). In this study, we engage in a narrative review of the available phase II and III literature on the efficacy and safety of HER2-targeting TKIs in the management of HER2-positive GC/GEJC.

MiR-27a promotes EMT in ovarian cancer through active Wnt/𝜷-catenin signalling by targeting FOXO1

BACKGROUND

Ovarian cancer (OC) is the fifth most common type of cancer in women worldwide. MiR-27a plays an important role in the development of ovarian cancer. However, the exact function and molecular mechanism of miR-27a in epithelial-mesenchymal transition (EMT) has not been thoroughly elucidated to date.

METHODS

Quantitative real-time PCR (qRT-PCR) was used to determine the expression of miR-27a and FOXO1 mRNA in ovarian tissues and cells. The function of miR-27a in ovarian cancer was investigated through overexpression and knockdown of miR-27a in vitro. Wound healing and Transwell assays were performed to evaluate the migration and invasive capacity of the cells. A luciferase reporter assay was conducted to confirm the interaction between miR-27a and FOXO1. Western blotting was used to evaluate FOXO1, EMT and Wnt/β-catenin relative protein expression.

RESULTS

In our study, we found that the mRNA expression level of miR-27a was significantly higher in ovarian cancer tissues and in HO8910 and OV90 cells. Functional experiments showed that miR-27a overexpression potentiated the migration and invasion of HO8910 and OV90 cells, while miR-27a inhibition reduced the cells' migration and invasion. Moreover, miR-27a upregulated the expression of mesenchymal cell markers and downregulated the expression of epithelial cell markers, which were restored via silencing of miR-27a expression. Subsequently, miR-27a was found to directly target and suppress the expression of FOXO1. Finally, we demonstrated that miR-27a promoted the progression of ovarian cancer cells and induced the process of EMT via the Wnt/β-catenin signalling pathway through inhibition of FOXO1.

CONCLUSIONS

Taken together, these results indicate that targeting miR-27a and FOXO1 could represent a strategy for anticancer therapy in ovarian cancer.

HSP90 inhibitor, AUY922, debilitates intrinsic and acquired lapatinib-resistant HER2-positive gastric cancer cells

Human epidermal growth factor receptor 2 (HER2) inhibitors, such as trastuzumab and lapatinib are used to treat HER2-positive breast and gastric cancers. However, as with other targeted therapies, intrinsic or acquired resistance to HER2 inhibitors presents unresolved therapeutic problems for HER2-positive gastric cancer. The present study describes investigations with AUY922, a heat shock protein 90 (HSP90) inhibitor, in primary lapatinib-resistant (ESO26 and OE33) and lapatinib-sensitive gastric cancer cells (OE19, N87, and SNU-216) harboring HER2 amplification/over-expression. In order to investigate whether AUY922 could overcome intrinsic and acquired resistance to HER2 inhibitors in HER2-positive gastric cancer, we generated lapatinib-resistant gastric cancer cell lines (OE19/LR and N87/LR) by continuous exposure to lapatinib in vitro. We found that activation of HER2 and protein kinase B (AKT) were key factors in inducing intrinsic and acquired lapatinib-resistant gastric cancer cell lines, and that AUY922 effectively suppressed activation of both HER2 and AKT in acquired lapatinib-resistant gastric cancer cell lines. In conclusion, AUY922 showed a synergistic anti-cancer effect with lapatinib and sensitized gastric cancer cells with intrinsic resistance to lapatinib. Dual inhibition of the HSP90 and HER2 signaling pathways could represent a potent therapeutic strategy to treat HER2-positive gastric cancer with intrinsic and acquired resistance to lapatinib.

Role of FoxO Proteins in Cellular Response to Antitumor Agents

FoxO proteins (FoxOs) are transcription factors with a common DNA binding domain that confers selectivity for DNA interaction. In human cells, four proteins (FoxO1, FoxO3, FoxO4 and FoxO6), with redundant activity, exhibit mainly a positive effect on genes involved in cell cycle, apoptosis regulation and drug resistance. Thus, FoxOs can affect cell response to antitumor agent treatment. Their transcriptional activity depends on post-translational modifications, including phosphorylation, acetylation, and mono/poly-ubiquitination. Additionally, alterations in microRNA network impact on FoxO transcripts and in turn on FoxO levels. Reduced expression of FoxO1 has been associated with resistance to conventional agents (e.g., cisplatin) and with reduced efficacy of drug combinations in ovarian carcinoma cells. FoxO3 has been shown as a mediator of cisplatin toxicity in colorectal cancer. A requirement for FoxO3-induced apoptosis has been reported in cells exposed to targeted agents (e.g., gefitinib). Recently, the possibility to interfere with FoxO1 localization has been proposed as a valuable approach to improve cell sensitivity to cisplatin, because nuclear retention of FoxO1 may favor the induction of pro-apoptotic genes. This review focuses on the role of FoxOs in drug treatment response in tumor cells and discusses the impact of the expression of these transcription factors on drug resistance/sensitivity.

The Dominant Role of Forkhead Box Proteins in Cancer

Forkhead box (FOX) proteins are multifaceted transcription factors that are significantly implicated in cancer, with various critical roles in biological processes. Herein, we provide an overview of several key members of the FOXA, FOXC, FOXM1, FOXO and FOXP subfamilies. Important pathophysiological processes of FOX transcription factors at multiple levels in a context-dependent manner are discussed. We also specifically summarize some major aspects of FOX transcription factors in association with cancer research such as drug resistance, tumor growth, genomic alterations or drivers of initiation. Finally, we suggest that targeting FOX proteins may be a potential therapeutic strategy to combat cancer.

Systems analysis of key genes and pathways in the progression of hepatocellular carcinoma

The carcinogenesis of hepatocellular carcinoma (HCC) is a complex process, starting from a chronically altered hepatic microenvironment due to liver cirrhosis and ultimately progressing to HCC. However, the sequential molecular alterations driving the malignant transformation in liver cirrhosis are not clearly defined.In this study, we obtained gene expression profiles of HCC, including 268 tumor tissues, 243 adjacent tumor tissues, and 40 cirrhotic tissues (GSE25097) from Gene Expression Omnibus (GEO), to comprehensively define changes in the transcriptome of HCC during the sequential evolution of liver cirrhosis into HCC.We showed that changes in the molecular profiles of cirrhotic and adjacent tumor samples were small and quite uniform, whereas there was a striking increase in the heterogeneity of tumors in HCC tissues at the mRNA level. A massive deregulation of key oncogenic molecules and pathways was observed from cirrhosis to HCC tumors. In addition, we focused on FOXO1 and DCN, 2 critical tumor suppressor genes that play an important role in liver cirrhosis and HCC development. FOXO1 and DCN expression levels were significantly reduced in tumor tissues compared with adjacent tumor tissues in HCC. Kaplan-Meier analysis revealed that FOXO1 and DCN expression was positively correlated with overall survival, defining FOXO1 and DCN as adverse prognostic biomarkers for HCC.This system-level research provided new insights into the molecular mechanisms of HCC carcinogenesis. FOXO1 and DCN may be applied as potential targets for HCC treatment in the future.

Nuclear division cycle 80 promotes malignant progression and predicts clinical outcome in colorectal cancer

Colorectal cancer (CRC) is a common human malignancy worldwide and increasing studies have attributed its malignant progression to abnormal molecular changes in cancer cells. Nuclear division cycle 80 (NDC80) is a newly discovered oncoprotein that regulates cell proliferation and cycle in numerous malignancies. However, its clinical significance and biological role in CRC remain unclear. Therefore, in this study, we firstly analyze its expression in a retrospective cohort enrolling 224 CRC patients and find its overexpression is significantly correlated with advanced tumor stage and poor prognosis in CRC patients. In addition, our result reveals it is an independent adverse prognostic factor affecting CRC-specific and disease-free survival. The subgroup analysis indicates NDC80 expression can stratify the clinical outcome in stage II and III patients, but fails in stage I and IV patients. In cellular assays, we find knockdown of NDC80 dramatically inhibits the proliferative ability, apoptosis resistance, cell cycle progression, and clone formation of CRC cells in vitro. Using xenograft model, we further prove knockdown of NDC80 also inhibits the tumorigenic ability of CRC cells in vivo. Finally, the microarray analysis is utilized to preliminarily clarify the oncogenic molecular mechanisms regulated by NDC80 and the results suggest it may promote CRC progression partly by downregulating tumor suppressors such as dual specificity phosphatase 5 and Forkhead box O1. Taken together, our study provides novel evidences to support that NDC80 is not only a promising clinical biomarker but also a potential therapeutical target for CRC precise medicine.

Trifluoperazine Activates FOXO1-Related Signals to Inhibit Tumor Growth in Hepatocellular Carcinoma

Schizophrenic patients tend to have reduced incidence of some cancers due to the treatment of antipsychotic drugs with antitumor effects, such as chlorpromazine and trifluoperazine (TFP). Forkhead Box O1 (FOXO1) as tumor suppressor in many malignancies is often inactivated by nuclear export, which could be inhibited by TFP. However, the antitumor efficiency of TFP and related role of FOXO1 in hepatocellular carcinoma (HCC) are unclear. Thus, two HCC cell lines SMMC-7721 and Bel-7402 were treated with different concentrations of TFP and the IC50 was determined. We found that TFP could inhibit the vitality of two cell lines and induce cell cycle arrest at G0/G1. Meanwhile, the apoptosis was also increased and the ability of migration or invasion was found to be impaired by TFP. Interestingly, TFP reversed the cytoplasmic localization of FOXO1 to nuclear and increased its expression in nuclear, and increased the ratio of Bax/Bcl-2. However, knockdown of FOXO1 significantly abrogated the TFP-induced apoptosis by decreasing the Bcl-2 expression [corrected]. Furthermore, we found that TFP in vivo could effectively restrict the angiogenesis and tumor growth with reduced expression of VEGF, Bcl-2, and PCNA, and increased the nuclear localization of FOXO1, which indicated its antitumor role in HCC.