FGFR2 alteration as a potential therapeutic target in poorly cohesive gastric carcinoma

Clinical Characteristics, Prognostic Factors and Therapeutic Strategies in Gastric Cancer Patients With Bone Metastasis: A Retrospective Analysis

BACKGROUND

Bone metastases are highly refractory and are associated with extremely poor survival. Despite the increasing incidence of bone metastasis in gastric cancer (GC), comprehensive analyses regarding the clinicopathological features, prognosis, and treatment of bone-metastatic GC remain limited.

METHODS

We obtained data from 120 bone-metastatic GC patients from Nanjing Drum Tower Hospital and 36,139 GC patients from the SEER database. Chi-square and Mann-Whitney U-tests evaluated clinicopathological features, while Cox models identified prognostic factors. Kaplan-Meier curves and forest plots assessed the effects of different treatment strategies on overall survival after bone metastasis (OS-BM).

RESULTS

Among 120 bone-metastatic GC patients, 55 (45.83%) were diagnosed with poorly cohesive gastric carcinoma (PCC). The higher incidence of bone metastasis was also observed in SRCC patients from the SEER database (p < 0.0001). PCC patients exhibited distinct pathological features compared to non-PCC patients, including lower PD-L1 (p = 0.042) and E-cadherin expression (p = 0.049). Multivariate analysis identified various negative prognostic factors such as metachronous bone metastasis (p < 0.001, HR = 2.35, 95% CI:1.47-3.74) and CA125 expression (p = 0.036, HR = 1.60, 95% CI:1.03-2.48), whereas immunotherapy was a positive prognostic factor (p < 0.001, HR = 0.44, 95% CI:0.29-0.66). Subgroup analysis also showed improved survival among different populations of bone-metastatic GC patients receiving immunotherapy. Moreover, combinational therapies including immunotherapy and other treatments (anti-angiogenic therapy and/or local radiotherapy) further improved patient OS-BM.

CONCLUSION

Our results suggest bone-metastatic GC patients exhibit distinct clinicopathological features, with a high incidence of bone metastasis in PCC. Immunotherapy-based combination therapies offer improved survival benefits, thus supporting the application of immunotherapy in GC patients at high risk of bone metastasis.

Synthesis and identification of a selective FGFR2 degrader with potent antiproliferative effects in gastric cancer

Despite numerous efforts to develop FGFR inhibitors for cancer treatment, the widespread clinical application of currently available FGFR inhibitors has been significantly limited due to the serious side effects caused by poor selectivity and resistance. PROTAC technology, a method for protein degradation, has shown notable advantages over conventional inhibitors. In our study, we coupled Erdafitinib, a pan-FGFR inhibitor, with a CRBN binder to synthesize and identify an effective FGFR2 degrader, N5. Our findings demonstrated that N5 displayed notable specificity for FGFR2 and outstanding enzyme inhibitory capabilities, achieving an IC50 value of 0.08 nM against FGFR2, and strong antiproliferative activity, maintaining an inhibitory rate above 50% on gastric cancer cells at a concentration of 0.17 nM. Mechanistically, N5 induced gastric cancer cell cycle arrest at the G0/G1 phase and apoptosis by decreasing the levels of FGFR downstream proteins. Moreover, N5 demonstrated favorable pharmacokinetic characteristics with a bioavailability of 74.8% when administered intraperitoneally and effectively suppressed the growth of SNU16 xenograft tumors, exhibiting greater potency compared to the parental inhibitor Erdafitinib. This study lays the groundwork for developing and potentially applying therapeutic agents targeting FGFR2 degradation.

Rediscovering immunohistochemistry in lung cancer

Several observations indicate that protein expression analysis by immunohistochemistry (IHC) remains relevant in individuals with non-small-cell lung cancer (NSCLC) when considering targeted therapy, as an early step in diagnosis and for therapy selection. Since the advent of next-generation sequencing (NGS), the role of IHC in testing for NSCLC biomarkers has been forgotten or ignored. We discuss how protein-level investigations maintain a critical role in defining sensitivity to lung cancer therapies in oncogene- and non-oncogene-addicted cases and in patients eligible for immunotherapy, suggesting that IHC testing should be reconsidered in clinical practice. We also argue how a panel of IHC tests should be considered complementary to NGS and other genomic assays. This is relevant to current clinical diagnostic practice but with potential future roles to optimize the selection of patients for innovative therapies. At the same time, strict validation of antibodies, assays, scoring systems, and intra- and interobserver reproducibility is needed.

Analysis of DNA methylation at birth and in childhood reveals changes associated with season of birth and latitude

BACKGROUND

Seasonal variations in environmental exposures at birth or during gestation are associated with numerous adult traits and health outcomes later in life. Whether DNA methylation (DNAm) plays a role in the molecular mechanisms underlying the associations between birth season and lifelong phenotypes remains unclear.

METHODS

We carried out epigenome-wide meta-analyses within the Pregnancy And Childhood Epigenetic Consortium to identify associations of DNAm with birth season, both at differentially methylated probes (DMPs) and regions (DMRs). Associations were examined at two time points: at birth (21 cohorts, N = 9358) and in children aged 1-11 years (12 cohorts, N = 3610). We conducted meta-analyses to assess the impact of latitude on birth season-specific associations at both time points.

RESULTS

We identified associations between birth season and DNAm (False Discovery Rate-adjusted p values < 0.05) at two CpGs at birth (winter-born) and four in the childhood (summer-born) analyses when compared to children born in autumn. Furthermore, we identified twenty-six differentially methylated regions (DMR) at birth (winter-born: 8, spring-born: 15, summer-born: 3) and thirty-two in childhood (winter-born: 12, spring and summer: 10 each) meta-analyses with few overlapping DMRs between the birth seasons or the two time points. The DMRs were associated with genes of known functions in tumorigenesis, psychiatric/neurological disorders, inflammation, or immunity, amongst others. Latitude-stratified meta-analyses [higher (≥ 50°N), lower (< 50°N, northern hemisphere only)] revealed differences in associations between birth season and DNAm by birth latitude. DMR analysis implicated genes with previously reported links to schizophrenia (LAX1), skin disorders (PSORS1C, LTB4R), and airway inflammation including asthma (LTB4R), present only at birth in the higher latitudes (≥ 50°N).

CONCLUSIONS

In this large epigenome-wide meta-analysis study, we provide evidence for (i) associations between DNAm and season of birth that are unique for the seasons of the year (temporal effect) and (ii) latitude-dependent variations in the seasonal associations (spatial effect). DNAm could play a role in the molecular mechanisms underlying the effect of birth season on adult health outcomes.

Molecular Landscape and Association With Crohn Disease of Poorly Cohesive Carcinomas of the Nonampullary Small Bowel

OBJECTIVES

Poorly cohesive carcinomas (PCCs) are neoplasms defined by a predominantly dyshesive growth pattern with single cell or cord-like stromal infiltration. The -distinctive clinicopathologic and prognostic features of small bowel PCCs (SB-PCCs) in comparison with conventional-type small intestinal adenocarcinomas have only recently been characterized. However, as SB-PCCs' genetic profile is still unknown, we aimed to analyze the molecular landscape of SB-PCCs.

METHODS

A next-generation sequencing analysis through Trusight Oncology 500 on a series of 15 nonampullary SB-PCCs was performed.

RESULTS

The most frequently found gene alterations were TP53 (53%) and RHOA (13%) mutations and KRAS amplification (13%), whereas KRAS, BRAF, and PIK3CA mutations were not identified. Most SB-PCCs (80%) were associated with Crohn disease, including both RHOA-mutated SB-PCCs, which featured a non-SRC-type histology, and showed a peculiar appendiceal-type, low-grade goblet cell adenocarcinoma (GCA)-like component. Rarely, SB-PCCs showed high microsatellite instability, mutations in IDH1 and ERBB2 genes, or FGFR2 amplification (one case each), which are established or promising therapeutic targets in such aggressive cancers.

CONCLUSIONS

SB-PCCs may harbor RHOA mutations, which are reminiscent of the diffuse subtype of gastric cancers or appendiceal GCAs, while KRAS and PIK3CA mutations, commonly involved in colorectal and small bowel adenocarcinomas, are not typical of such cancers.

Expression levels of RUNX3 and FGFR2 in peripheral blood of severe acute pancreatitis and their clinical significance

Purpose

Severe acute pancreatitis (SAP) is a life-threatening inflammatory syndrome of the pancreas. This study aimed to analyze the clinical significance of runt-associated transcription factor 3 (RUNX3) and fibroblast growth factor receptor 2 (FGFR2) expression alterations in SAP.

Methods

This study included 18 SAP patients in Wuzhong People's Hospital from November 2019 to December 2021 and 18 healthy controls. RUNX3 and FGFR2 expression levels were determined by RT-quantitative PCR. Correlations between RUNX3/FGFR2 and sex, age, etiology, CRP, procalcitonin, AST, LDH, BUN, Acute Physiology and Chronic Health Evaluation II (APACHE II), Ranson score, Bedside Index for Severity in Acute Pancreatitis (BISAP) score, sequential organ failure assessment (SOFA), and modified computed tomography severity index (MCTSI) score were analyzed. Diagnostic values of RUNX3 and FGFR2 in SAP were analyzed using the receiver-operating characteristic curve. The binding of RUNX3 to FGFR2 was analyzed by chromatin immunoprecipitation.

Results

RUNX3 and FGFR2 were downregulated in peripheral blood of SAP patients. RUNX3 and FGFR2 were negatively correlated with CRP, procalcitonin, AST, LDH, BUN, APACHE II score, Ranson score, BISAP score, SOFA score, and MCTSI score. Sensitivity and specificity of RUNX3 level of <0.9650 for SAP diagnosis were 88.89% and 72.22%, respectively. Sensitivity and specificity of FGFR2 level of <0.8950 for SAP diagnosis were 66.67% and 83.33%, respectively. RUNX3 was enriched in the FGFR2 promoter and was positively correlated with FGFR2.

Conclusion

RUNX3 and FGFR2 were downregulated in peripheral blood of SAP patients and served as candidate biomarkers for SAP diagnosis. RUNX3 bound to the FGFR2 promoter to promote FGFR2 transcription.

Integrative analysis of the proteome and transcriptome in gastric cancer identified LRP1B as a potential biomarker

Background: The aim of this study was to discover unique membrane proteins associated with gastric cancer (GC) in proteomics analysis. Methods: Using a data-independent acquisition strategy, we compared the relative expression levels of membrane proteins in GC. Results: A total of 2774 differentially expressed membrane proteins were identified between GC and normal cell lines. Conjoint analysis of transcriptomes and proteomes provided 11 potential biomarkers (GPRC5A, PSAT1, NUDCD1, RCC2, IPO4, FAM91A1, KANK2, PRADC1, NME4, METTL7A and LRP1B) for further exploration. Downregulation of LRP1B in GC was validated by immunohistochemistry. Moreover, LRP1B demonstrated an area under the receiver operating characteristic curve of 0.917 in differentiating GC from normal tissues. Conclusion: LRP1B was identified as a meaningful indicator assisting in GC detection and labeling of tumor boundaries.

Serological and Molecular Characterization of Hepatitis B Virus Infection in Gastric Cancer

Hepatitis B virus (HBV) infection has been reported to be associated with gastric cancer (GC). Nonetheless, no study has revealed the role of HBV infection in the survival of patients with GC, and the mutation profiles of HBV-infected patients with GC have never been documented. Here, we performed an updated meta-analysis and found a significantly increased risk of GC in HBV-infected individuals (sOR, 1.29; 95% CI, 1.22-1.37). Furthermore, we observed that in the Anhui area, the rate of serum HBsAg positivity (OR, 1.62; 95% CI, 1.03-2.55) was significantly higher in GC patients than in controls. Moreover, our results showed that HBV-positive patients had significantly worse disease-free survival (HR, 1.98; 95% CI, 1.39-2.82) and overall survival (HR, 1.84; 95% CI, 1.19-2.85) than HBV-negative patients. The results of Cox proportional hazards regression proved that HBV infection was an independent adverse prognostic factor in GC. Furthermore, by performing targeted-NGS, we found unique mutation profiles in HBV-infected GC samples, including five frequently mutated protein-coding genes (KMT2B, KMT2D, SOX1, FGF12, and TUBB2B). Expression and survival analyses of these genes identified three novel candidate genes that may have potential roles in GC development. Gene Ontology enrichment analysis showed that the recurrent mutations in HBV-positive GC samples were related to cell proliferation, cell migration, and transcription. Taking together, our study proved that HBV infection is an independent prognostic factor in GC patients. The unique mutation profiles of HBV-infected patients with GC open a new research direction toward the underling mechanism between HBV infection and GC.

FGFR2 overexpression and compromised survival in diffuse-type gastric cancer in a large central European cohort

The significance of fibroblast growth factor receptor 2 (FGFR2) in gastric cancer (GC) has been studied predominantly in Asian patient cohorts. Data on White patients are scarce. Here, we aimed to independently validate the expression and putative tumor biological significance of FGFR2 in a large non-Asian GC cohort. Immunohistochemistry (IHC) was performed on large-area tissue sections from 493 patients with GC and evaluated using the HScore. GCs with moderate and strong FGFR2 expression were studied for Fgfr2 amplification using chromogenic in situ hybridization (CISH). Median overall survival was determined using the Kaplan–Meier method. The majority [240 (99.1%)] of FGFR2-positive GCs showed a variable combination of staining intensities with marked intratumoral heterogeneity, including weak [198 (40.2%) cases], moderate [145 (29.4%)], and strong [108 (21.9%)] staining in diverse combinations. 250 (50.9%) GCs expressed no FGFR2. Fgfr2 gene amplification was found in 40% of selected cases with high protein expression and was also heterogeneous at the cell level. FGFR2 protein expression did not correlate with patient survival in the entire cohort However, using different cutoff values, a negative correlation between FGFR2-expression and patient outcome was found for diffuse-type GC. FGFR2 expression was associated with a lower tumor grade and intestinal phenotype (p≤0.0001). FGFR2–positive diffuse-type GCs classify a small subset of patients with a poor tumor specific survival (5.29±1.3 vs. 14.67±1.9 months; p = 0.004).