Simultaneous Acquisition of T790M Mutation and SCLC Transformation during Targeted Therapy in EGFR-Mutated Lung Adenocarcinoma: A Rare Case Report.

BACKGROUND Various resistance mechanisms of the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) have been reported, and approximately half of the cases show a T790M point mutation as resistance to EGFR-TKI. In addition, 3-14% of cases of non-small cell lung cancer transform into small cell lung carcinoma (SCLC) during treatment. However, there are few reported cases in which 2 mechanisms of resistance have been observed simultaneously. This report describes a 66-year-old man with initial presentation of stage IIA right-sided lung adenocarcinoma with EGFR gene exon 21 L858R mutation and 3 years of stable disease. During treatment with erlotinib, the patient developed SCLC and adenocarcinoma with EGFR exon 21 L858R and exon 20 T790M mutation. CASE REPORT A 66-year-old man underwent right pneumonectomy plus nodal dissection 2a for right hilar lung cancer and was diagnosed with an EGFR exon21 L858R mutated lung adenocarcinoma. Three years later, pleural dissemination was observed in the right chest wall. Although erlotinib was continued for 52 months, new metastases to the right ribs were detected. Chest wall tumor resection was performed. Based on the World Health Organization classification, the patient was diagnosed with combined SCLC, with EGFR exon21 L858R and exon20 T790M mutation. The patient received 4 cycles of carboplatin plus etoposide, 14 cycles of amrubicin, and 2 cycles of irinotecan. Chemotherapy continued for 25 months. CONCLUSIONS Long-term survival was achieved by chemotherapy after transformation. Since EGFR mutation-positive lung cancer shows a variety of acquired resistances, it is important to consider the treatment strategy of performing re-biopsy.

Molecular Pathology of Gastroesophageal Cancer.

Upper gastroesophageal carcinomas consist of cancers arising from the esophagus and stomach. Squamous cell carcinomas and adenocarcinomas are seen in the esophagus and despite arising from the same organ have different biology. Gastric adenocarcinomas are categorized into 4 molecular subtypes: high Epstein-Barr virus load, microsatellite unstable cancers, chromosomal unstable (CIN) cancers, and genomically stable cancers. Genomically stable gastric cancers correlate highly with histologically defined diffuse-type cancers. Esophageal carcinomas and CIN gastric cancers often are driven by high-level amplifications of oncogenes and contain a high degree of intratumoral heterogeneity. Targeted therapeutics is an active area of research for gastroesophageal cancers.

Human plasma can modulate micronucleus frequency in TK6 and OE33 cells in vitro.

In this paper, we studied the potential genotoxic effects of human plasma from healthy volunteers, as well as patients with gastro-oesophageal reflux disease, Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC) using the oesophageal adenocarcinoma cell line (OE33) and the lymphoblastoid cell line (TK6). Both TK6 and OE33 cells were treated with plasma (10 % volume, replacing foetal bovine serum (FBS) or horse serum (HS)) at different time points of 4 h (for the micronucleus (Mn) assay and the invasion assay) and 24 h (for the cell cycle studies). Plasma-induced effects on DNA damage levels, cell viability and the cell cycle were studied by the micronucleus assay, cytokinesis block proliferation index (CBPI) and flow cytometry respectively. The expression of IL-8 in supernatants of TK6 cells and IFN-ß in OE33 cells was also analysed by enzyme-linked immunosorbent assay (ELISA). Finally, we carried out an assessment of cellular invasion of OE33 cells following plasma treatment. The results of the micronucleus assay confirmed the genotoxicity of direct plasma treatment from some participants through the increase in DNA damage in TK6 cells. Conversely, some individual patient plasma samples reduced background levels of TK6 cell Mn frequency, in an anti-genotoxic fashion. In TK6 cells, (on average) plasma samples from patients with Barrett's oesophagus induced higher micronucleus levels than healthy volunteers (p= 0.0019). There was little difference in Mn induction when using plasma versus serum to treat the cells in vitro. Cell cycle results showed that direct plasma treatment had a marked impact on OE33 cells at 24 h (p=0.0182 for BO and p=0.0320 for OAC) by decreasing the proportion of cells in the S phase, while plasma exposure was less impactful on the cell cycle of TK6 cells. Invasion of OE33 cells was also seen to be non-significantly affected by plasma treatment of OE33 cells. The addition of N-acetyl cysteine NAC in a dose-dependent matter did not alter the formation of Mn in TK6 cells, suggesting that reactive oxygen species (ROS) are not the root cause of plasma's genotoxicity. The concentration of IL-8 in TK6 cells and IFN-ß in OE33 cells was significantly higher in cells treated with OAC-derived plasma than in the untreated negative control. Collectively, our results demonstrate that plasma-specific effects are detectable which helps us better understand some important aspects of the biology of blood-based biomarkers under development.

siRNA-based therapy for gastric adenocarcinoma: what's next step?

Gastric cancer continues to have a high death rate despite advancements in their diagnosis and treatment. Novel treatment techniques are thus desperately needed. This is where double-stranded RNA molecules known as small interfering RNA (siRNA), which may selectively target the mRNA of disease-causing genes, may find use in medicine. For siRNAs to function properly in the human body, they must be shielded from deterioration. Furthermore, in order to maintain organ function, they must only target the tumor and spare normal tissue. siRNAs have been designed using clever delivery mechanisms including polymers and lipids to achieve these objectives. Although siRNA protection is not hard to acquire, it is still challenging to target cancer cells with them. Here, we first discuss the basic characteristics of gastric cancer before describing the properties of siRNA and typical delivery methods created specifically for gastric tumors. Lastly, we provide a succinct overview of research using siRNAs to treat gastric tumors.

Disentangling oncogenic amplicons in esophageal adenocarcinoma.

Esophageal adenocarcinoma is a prominent example of cancer characterized by frequent amplifications in oncogenes. However, the mechanisms leading to amplicons that involve breakage-fusion-bridge cycles and extrachromosomal DNA are poorly understood. Here, we use 710 esophageal adenocarcinoma cases with matched samples and patient-derived organoids to disentangle complex amplicons and their associated mechanisms. Short-read sequencing identifies ERBB2, MYC, MDM2, and HMGA2 as the most frequent oncogenes amplified in extrachromosomal DNAs. We resolve complex extrachromosomal DNA and breakage-fusion-bridge cycles amplicons by integrating of de-novo assemblies and DNA methylation in nine long-read sequenced cases. Complex amplicons shared between precancerous biopsy and late-stage tumor, an enrichment of putative enhancer elements and mobile element insertions are potential drivers of complex amplicons' origin. We find that patient-derived organoids recapitulate extrachromosomal DNA observed in the primary tumors and single-cell DNA sequencing capture extrachromosomal DNA-driven clonal dynamics across passages. Prospectively, long-read and single-cell DNA sequencing technologies can lead to better prediction of clonal evolution in esophageal adenocarcinoma.

Evaluating the predictive value of angiogenesis-related genes for prognosis and immunotherapy response in prostate adenocarcinoma using machine learning and experimental approaches.

Background: Angiogenesis, the process of forming new blood vessels from pre-existing ones, plays a crucial role in the development and advancement of cancer. Although blocking angiogenesis has shown success in treating different types of solid tumors, its relevance in prostate adenocarcinoma (PRAD) has not been thoroughly investigated. Method: This study utilized the WGCNA method to identify angiogenesis-related genes and assessed their diagnostic and prognostic value in patients with PRAD through cluster analysis. A diagnostic model was constructed using multiple machine learning techniques, while a prognostic model was developed employing the LASSO algorithm, underscoring the relevance of angiogenesis-related genes in PRAD. Further analysis identified MAP7D3 as the most significant prognostic gene among angiogenesis-related genes using multivariate Cox regression analysis and various machine learning algorithms. The study also investigated the correlation between MAP7D3 and immune infiltration as well as drug sensitivity in PRAD. Molecular docking analysis was conducted to assess the binding affinity of MAP7D3 to angiogenic drugs. Immunohistochemistry analysis of 60 PRAD tissue samples confirmed the expression and prognostic value of MAP7D3. Result: Overall, the study identified 10 key angiogenesis-related genes through WGCNA and demonstrated their potential prognostic and immune-related implications in PRAD patients. MAP7D3 is found to be closely associated with the prognosis of PRAD and its response to immunotherapy. Through molecular docking studies, it was revealed that MAP7D3 exhibits a high binding affinity to angiogenic drugs. Furthermore, experimental data confirmed the upregulation of MAP7D3 in PRAD, correlating with a poorer prognosis. Conclusion: Our study confirmed the important role of angiogenesis-related genes in PRAD and identified a new angiogenesis-related target MAP7D3.

Novel lactylation-related signature to predict prognosis for pancreatic adenocarcinoma.

BACKGROUND: Lactate, previously considered a metabolic byproduct, is pivotal in cancer progression and maintaining the immunosuppressive tumor microenvironment. Further investigations confirmed that lactate is a primary regulator, introducing recently described post-translational modifications of histone and non-histone proteins, termed lysine lactylation. Pancreatic adenocarcinomas are characterized by increased glycolysis and lactate accumulation. However, our understanding of lactylation-related genes in pancreatic adenocarcinomas remains limited. AIM: To construct a novel lactylation-related gene signature to predict the survival of patients with pancreatic cancer. METHODS: RNA-seq and clinical data of pancreatic adenocarcinoma (PDAC) were obtained from the GTEx (Genotype-Tissue Expression) and TCGA (The Cancer Genome Atlas) databases via Xena Explorer, and GSE62452 datasets from GEO. Data on lactylation-related genes were obtained from publicly available sources. Differential expressed genes (DEGs) were acquired by using R package "DESeq2" in R. Univariate COX regression analysis, LASSO Cox and multivariate Cox regressions were produced to construct the lactylation-related prognostic model. Further analyses, including functional enrichment, ESTIMATE, and CIBERSORT, were performed to analyze immune status and treatment responses in patients with pancreatic cancer. PDAC and normal human cell lines were subjected to western blot analysis under lactic acid intervention; two PDAC cell lines with the most pronounced lactylation were selected. Subsequently, RT-PCR was employed to assess the expression of LRGs genes; SLC16A1, which showed the highest expression, was selected for further investigation. SLC16A1-mediated lactylation was analyzed by immunofluorescence, lactate production analysis, colony formation, transwell, and wound healing assays to investigate its role in promoting the proliferation and migration of PDAC cells. In vivo validation was performed using an established tumor model. RESULTS: In this study, we successfully identified 10 differentially expressed lactylation-related genes (LRGs) with prognostic value. Subsequently, a lactylation-related signature was developed based on five OS-related lactylation-related genes (SLC16A1, HLA-DRB1, KCNN4, KIF23, and HPDL) using Lasso Cox hazard regression analysis. Subsequently, we evaluated the clinical significance of the lactylation-related genes in pancreatic adenocarcinoma. A comprehensive examination of infiltrating immune cells and tumor mutation burden was conducted across different subgroups. Furthermore, we demonstrated that SLC16A1 modulates lactylation in pancreatic cancer cells through lactate transport. Both in vivo and in vitro experiments showed that decreasing SLC16A1 Level and its lactylation significantly inhibited tumor progression, indicating the potential of targeting the SLC16A1/Lactylation-associated signaling pathway as a therapeutic strategy against pancreatic adenocarcinoma. CONCLUSION: We constructed a novel lactylation-related prognostic signature to predict OS, immune status, and treatment response of patients with pancreatic adenocarcinoma, providing new strategic directions and antitumor immunotherapies.

Assessing Mismatch Repair Expression by Immunohistochemistry in Colorectal Adenocarcinoma -Insight from a Tertiary Care Centre.

BACKGROUND: Microsatellite instability (MSI) is a pattern of hyper mutation that occurs at microsatellite level in the genome and result due to error in the mismatch repair system. MSI is caused by defective mismatch repair (MMR) genes associated with either hyper methylation of MMR genes or BRAF mutations. Anti-MLH-1, anti-MSH-2, anti-MSH-6 and anti-PMS2 monoclonal antibodies are used for Immunohistochemical analysis. METHODS: The immunohistochemical expression of MSI proteins were assessed in 72 cases of colorectal carcinoma. These were classified based on the expression of MLH1, MSH2, MSH6 and PMS2 proteins. RESULTS: There were 57 percent of cases showing loss of at least one antibodies, and 43 percent cases showing intact expression of all antibodies (MLH1, MSH2, MSH6 and PMS2). CONCLUSION: In conclusion, our study provides valuable insights into the expression of mismatch repair in colorectal adenocarcinoma through immunohistochemistry analysis conducted at our tertiary care centre. These findings hold significant clinical implications, suggesting further testing for BRAF and MLH1 Promoter Hypermethylation to confirm possibility of Lynch syndrome. KEY WORDS: IHC, MMR, CRC.

Genome-wide investigation of lncRNAs revealed their tight association with gastric cancer.

BACKGROUND: Gastric cancer (GC) is a significant health issue globally, ranking as the fifth most common cancer with over 10,000 new cases reported annually. Long non-coding RNA (lncRNA) has emerged as a critical player in cellular functions, influencing GC's development, growth, metastasis, and prognosis. However, our understanding of lncRNA's role in the pathogenesis of GC remains limited. Therefore, it is particularly important to explore the relationship between lncRNA and gastric cancer. METHODS: we conducted a comprehensive analysis of RNA sequencing data from the GEO database and stomach adenocarcinoma (STAD) data from the TCGA database to identify lncRNAs that exhibit altered expression levels in GC and the mechanisms underlying lncRNA-mediated transcription and post-transcriptional regulation were explored. RESULTS: This study uncovered 94 lncRNAs with differential expression and, through co-expression analysis, linked these to 1508 differentially expressed genes (DEGs). GO functional enrichment analysis highlighted that these DEGs are involved in critical pathways, such as cell adhesion and the positive regulation of cell migration. By establishing a lncRNA-miRNA-mRNA regulatory network, we found that the ceRNA mechanism, particularly involving RP11-357H14.17 and CTD-2377D24.4, could play a role in GC progression. Experimental validation of selected differentially expressed lncRNAs and mRNAs (including RP11-357H14.17-CLDN1, BBOX1, TRPM2-AS, CLDN1, PLAU, HOXB7) confirmed the RNA-seq results. CONCLUSIONS: Overall, our findings highlight the critical role of the lncRNA-mRNA regulatory network in the development and progression of GC, offering potential biomarkers for diagnosis and targets for innovative treatment strategies.

A Novel Gene Fusion YLPM1::PRKD1 Identified in a Cribriform Subtype of Polymorphous Adenocarcinoma.

Cribriform adenocarcinoma of the salivary gland (CASG) is an entity that is currently classified under polymorphous adenocarcinoma (PAC), cribriform subtype per the 2022 WHO classification of head and neck tumours. There is debate about whether CASG should be considered a separate diagnostic entity, as CASG differs from conventional PAC in anatomic site, clinical behaviors, and molecular patterns. Herein we describe a challenging and unique case which shares histologic and behavioral features between CASG and conventional PAC with a YLPM1::PRKD1 rearrangement not previously reported in the literature.

Development and assessment of an RNA editing-based risk model for the prognosis of cervical cancer patients.

RNA editing, as an epigenetic mechanism, exhibits a strong correlation with the occurrence and development of cancers. Nevertheless, few studies have been conducted to investigate the impact of RNA editing on cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC). In order to study the connection between RNA editing and CESC patients' prognoses, we obtained CESC-related information from The Cancer Genome Atlas (TCGA) database and randomly allocated the patients into the training group or testing group. An RNA editing-based risk model for CESC patients was established by Cox regression analysis and least absolute shrinkage and selection operator (LASSO). According to the median score generated by this RNA editing-based risk model, patients were categorized into subgroups with high and low risks. We further constructed the nomogram by risk scores and clinical characteristics and analyzed the impact of RNA editing levels on host gene expression levels and adenosine deaminase acting on RNA. Finally, we also compared the biological functions and pathways of differentially expressed genes (DEGs) between different subgroups by enrichment analysis. In this risk model, we screened out 6 RNA editing sites with significant prognostic value. The constructed nomogram performed well in forecasting patients' prognoses. Furthermore, the level of RNA editing at the prognostic site exhibited a strong correlation with host gene expression. In the high-risk subgroup, we observed multiple biological functions and pathways associated with immune response, cell proliferation, and tumor progression. This study establishes an RNA editing-based risk model that helps forecast patients' prognoses and offers a new understanding of the underlying mechanism of RNA editing in CESC.

Identification of extracellular matrix-related biomarkers in colon adenocarcinoma by bioinformatics and experimental validation.

Backgrounds: Extracellular matrix (ECM) is an important component of tumor microenvironment, and its abnormal expression promotes tumor formation, progression and metastasis. Methods: Weighted gene co-expression network analysis (WGCNA) was used to identify ECM-related hub genes based on The Cancer Genome Atlas (TCGA) colon adenocarcinoma (COAD) data. COAD clinical samples were used to verify the expression of potential biomarkers in tumor tissues, and siRNA was used to explore the role of potential biomarkers in cell proliferation and epithelial-mesenchymal transition (EMT). Results: Three potential biomarkers (LEP, NGF and PCOLCE2) related to prognosis of COAD patients were identified and used to construct ERGPI. Immunohistochemical analysis of clinical samples showed that the three potential biomarkers were highly expressed in tumor tissues of COAD patients. Knockdown of LEP, NGF or PCOLCE2 inhibited COAD cell proliferation and EMT. Dictamnine inhibited tumor cell growth by binding to these three potential biomarkers based on molecular docking and transplanted tumor model. Conclusion: The three biomarkers can provide new ideas for the diagnosis and targeted therapy of COAD patients.

Differential Tumor Gene Expression Profiling of Patients With Prostate Adenocarcinoma on the Basis of BMI.

PURPOSE: An increased BMI is linked to increased prostate adenocarcinoma incidence and mortality. Baseline tumor gene expression profiling (GEP) can provide a comprehensive picture of the biological processes related to treatment response and disease progression. We interrogate and validate the underlying differences in tumor GEP on the basis of BMI in patients with prostate adenocarcinoma. METHODS: The inclusion criteria consisted of histologically confirmed prostate adenocarcinoma and the availability of RNA sequencing data obtained from treatment-naïve primary prostate tissue. RNA sequencing was performed by a Clinical Laboratory Improvement Amendments-certified laboratory (Tempus or Caris Life Sciences). The Tempus cohort was used for interrogation and the Caris cohort for validation. Patients were stratified on the basis of BMI at the time of prostate cancer diagnosis: BMI-high (BMIH; BMI ≥30) and BMI-low (BMIL; BMI <30). Differential gene expression analysis between the two cohorts was conducted using the DEseq2 pipeline. The resulting GEPs were further analyzed using Gene Set Enrichment software to identify pathways that exhibited enrichment in each cohort. RESULTS: Overall, 102 patients were eligible, with 60 patients in the Tempus cohort (BMIL = 38, BMIH = 22) and 42 patients in the Caris cohort (BMIL = 24, BMIH = 18). Tumor tissues obtained from patients in the BMIL group exhibited higher expression of genes associated with inflammation pathways. BMIH displayed increased expression of genes involved in pathways such as heme metabolism and androgen response. CONCLUSION: Our study shows the upregulation of distinct genomic pathways in BMIL compared with BMIH patients with prostate cancer. These hypothesis-generating data could explain different survival outcomes in both groups and guide personalized therapy for men with prostate cancer.

NSUN6 mediates 5-methylcytosine modification of METTL3 and promotes colon adenocarcinoma progression.

Colon adenocarcinoma (COAD) is a common and fatal malignant tumor of digestive system with complex etiology. 5-Methylcytosine (m5C) modification of RNA by the NSUN gene family (NSUN1-NSUN7) and DNMT2 reshape cell biology and regulate tumor development. However, the expression profile, prognostic significance and function of these m5C modifiers in COAD remain largely unclear. By mining multiple integrated tumor databases, we found that NSUN1, NSUN2, NSUN5, and NSUN6 were overexpressed in COAD tumor samples relative to normal samples. Clinically, high expression of NSUN6 was significantly associated with shorter survival (including both disease-free survival and overall survival) in COAD patients. NSUN6 was further confirmed to be upregulated at both tissue and cellular levels of COAD, suggesting that NSUN6 plays a critical role in disease progression. Through comprehensive gene enrichment analysis and cell-based functional validation, it was revealed that NSUN6 promoted the cell cycle progression and cell proliferation of COAD. Mechanistically, NSUN6 upregulates the expression of oncogenic METTL3 and catalyzes its m5C modification in COAD cells. Overexpression of METTL3 significantly relieved the cell cycle inhibition of COAD caused by NSUN6 deficiency. Furthermore, NSUN6 was negatively associated with the abundance of infiltrating immune cells in COAD tumors, such as activated B cells, natural killer cells, effector memory CD8 T cells, and regulatory T cells. Importantly, pan-cancer analysis further uncovered that NSUN6 was dysregulated and heterogeneous in various tumors. Thus our findings extend the role of m5C transferase in COAD and suggest that NSUN6 is a potential biomarker and target for this malignancy.

An investigation of the clinical impact and therapeutic relevance of a DNA damage immune response (DDIR) signature in patients with advanced gastroesophageal adenocarcinoma.

BACKGROUND: An improved understanding of which gastroesophageal adenocarcinoma (GOA) patients respond to both chemotherapy and immune checkpoint inhibitors (ICI) is needed. We investigated the predictive role and underlying biology of a 44-gene DNA damage immune response (DDIR) signature in patients with advanced GOA. MATERIALS AND METHODS: Transcriptional profiling was carried out on pretreatment tissue from 252 GOA patients treated with platinum-based chemotherapy (three dose levels) within the randomized phase III GO2 trial. Cross-validation was carried out in two independent GOA cohorts with transcriptional profiling, immune cell immunohistochemistry and epidermal growth factor receptor (EGFR) fluorescent in situ hybridization (FISH) (n = 430). RESULTS: In the GO2 trial, DDIR-positive tumours had a greater radiological response (51.7% versus 28.5%, P = 0.022) and improved overall survival in a dose-dependent manner (P = 0.028). DDIR positivity was associated with a pretreatment inflamed tumour microenvironment (TME) and increased expression of biomarkers associated with ICI response such as CD274 (programmed death-ligand 1, PD-L1) and a microsatellite instability RNA signature. Consensus pathway analysis identified EGFR as a potential key determinant of the DDIR signature. EGFR amplification was associated with DDIR negativity and an immune cold TME. CONCLUSIONS: Our results indicate the importance of the GOA TME in chemotherapy response, its relationship to DNA damage repair and EGFR as a targetable driver of an immune cold TME. Chemotherapy-sensitive inflamed GOAs could benefit from ICI delivered in combination with standard chemotherapy. Combining EGFR inhibitors and ICIs warrants further investigation in patients with EGFR-amplified tumours.

SKA3 Expression as a Prognostic Factor for Patients with Pancreatic Adenocarcinoma.

The spindle and kinetochore-associated complex subunit 3 (SKA3) is a protein essential for proper chromosome segregation during mitosis and thus responsible for maintaining genome stability. Although its involvement in the pathogenesis of various cancer types has been reported, the potential clinicopathological significance of SKA3 in pancreatic ductal adenocarcinoma (PDAC) has not been fully elucidated. Therefore, this study aimed to assess clinicopathological associations and prognostic value of SKA3 in PDAC. For this purpose, in-house immunohistochemical analysis on tissue macroarrays (TMAs), as well as a bioinformatic examination using publicly available RNA-Seq dataset, were performed. It was demonstrated that SKA3 expression at both mRNA and protein levels was significantly elevated in PDAC compared to control tissues. Upregulated mRNA expression constituted an independent unfavorable prognostic factor for the overall survival of PDAC patients, whereas altered SKA3 protein levels were associated with significantly better clinical outcomes. The last observation was particularly clear in the early-stage tumors. These findings render SKA3 a promising prognostic biomarker for patients with pancreatic ductal adenocarcinoma. However, further studies are needed to confirm this conclusion.

EGFR and PI3K Signalling Pathways as Promising Targets on Circulating Tumour Cells from Patients with Metastatic Gastric Adenocarcinoma.

The prognosis for metastatic gastric adenocarcinoma (mGAC) remains poor. Gene alterations in receptor tyrosine kinases (RTKs) such as epidermal growth factor receptor (EGFR) and their downstream effectors including catalytic subunit alpha of the phosphatidylinositol 3-kinase (PIK3CA) are common in mGAC. Targeted RTK and phosphatidylinositol-3-kinase (PI3K) treatments have demonstrated clinical benefits in other solid tumours and are key potential targets for clinical development against mGAC given the presence of recurrent alterations in these pathways. Furthermore, combination RTK/PI3K treatments may overcome compensatory mechanisms that arise using monotherapies, leading to improved patient outcomes. Herein, we investigated RTK/PI3K single and combination drug responses against our unique human mGAC-derived PIK3CA gain-of-function mutant, human epidermal growth factor receptor 2 (HER2)-negative, EGFR-expressing circulating tumour cell line, UWG02CTC, under two- and three-dimensional culture conditions to model different stages of metastasis. UWG02CTCs were highly responsive to the PI3K p110α-subunit targeted drugs PIK-75 (IC50 = 37.0 ± 11.1 nM) or alpelisib (7.05 ± 3.7 µM). Drug sensitivities were significantly increased in 3D conditions. Compensatory MAPK/ERK pathway upregulation by PI3K/Akt suppression was overcome by combination treatment with the EGFR inhibitor gefitinib, which was strongly synergistic. PIK-75 plus gefitinib significantly impaired UWG02CTC invasion in an organotypic assay. In conclusion, UWG02CTCs are a powerful ex vivo mGAC drug responsiveness model revealing EGFR/PI3K-targeted drugs as a promising combination treatment option for HER2-negative, RAS wild-type mGAC patients.

Single-cell and spatial transcriptomics analysis of non-small cell lung cancer.

Lung cancer is the second most frequently diagnosed cancer and the leading cause of cancer-related mortality worldwide. Tumour ecosystems feature diverse immune cell types. Myeloid cells, in particular, are prevalent and have a well-established role in promoting the disease. In our study, we profile approximately 900,000 cells from 25 treatment-naive patients with adenocarcinoma and squamous-cell carcinoma by single-cell and spatial transcriptomics. We note an inverse relationship between anti-inflammatory macrophages and NK cells/T cells, and with reduced NK cell cytotoxicity within the tumour. While we observe a similar cell type composition in both adenocarcinoma and squamous-cell carcinoma, we detect significant differences in the co-expression of various immune checkpoint inhibitors. Moreover, we reveal evidence of a transcriptional "reprogramming" of macrophages in tumours, shifting them towards cholesterol export and adopting a foetal-like transcriptional signature which promotes iron efflux. Our multi-omic resource offers a high-resolution molecular map of tumour-associated macrophages, enhancing our understanding of their role within the tumour microenvironment.

Integrated analysis identified the role of three family members of ARHGAP in pancreatic adenocarcinoma.

The Rho GTPase activating protein family (ARHGAPs) is expressed in pancreatic adenocarcinoma (PAAD) but its function is unclear. The aim of this study was to explore the role and potential clinical value of ARHGAPs in PAAD. Using TCGA and GEO databases to analyze expression of ARHGAPs in PAAD and normal tissues. Survival curve was drawn by Kaplan-Meier. ARHGAPs were integrated analyzed by GEPIA2, TIMER, UCLCAN, cBioPortal and R language. Protein level and prognostic value were evaluated via IHC staining or survival analysis. We totally identify 18 differentially expressed (DE) ARHGAPs in PAAD. Among the 18 DE genes, 8 were positively correlated with tumor grade; abnorrmal expression of 5 was positively correlated with copy number variation; expression of 4 was positively correlated with promoter hypomethylation. Multivariate Cox regression identified ARHGAP5, ARHGAP11A, and ARHGAP12 as independent prognostic factors of PAAD. The function of ARHGAPs was mainly related to GTPase activity and signaling, axon guidance, proteoglycans in cancer and focal adhesion. Expression of 7 ARHGAPs was strongly correlated with immune infiltration. Immunohistochemistry showed increased protein levels of ARHGAP5, ARHGAP11A, and ARHGAP12 in PAAD tissues. Survival analysis confirmed a negative correlation between ARHGAP5, ARHGAP11A, and ARHGAP12 expression and patient prognosis. Multivariate Cox regression proved ARHGAP5, ARHGAP11A, and ARHGAP12 could serve as independent prognostic indicators for PAAD. Finally, this study verified ARHGAP5, ARHGAP11A, and ARHGAP12 as independent prognostic factors in PAAD, suggesting their significance for the diagnosis and treatment of PAAD.

[Establishment of Dual Fluorescent Labeled Human High Bone Metastasis 
Lung Adenocarcinoma Cell Line and Transcriptomic Characterization Analysis].

BACKGROUND: Bone is a common site for metastasis in lung adenocarcinoma, but the mechanism behind lung adenocarcinoma bone metastasis is still unclear. And currently, there is a lack of easily traceable and stable lung adenocarcinoma bone metastasis cell models, which limits the research on the mechanism of lung adenocarcinoma bone metastasis. The establishment of human lung adenocarcinoma cell line that are highly metastatic to bone, labeled with green fluorescent proteins (GFP) and fireflies luciferase (LUC), along with transcriptomic characterization, would be beneficial for research on lung adenocarcinoma bone metastasis and provide new experimental methods. METHODS: The human lung adenocarcinoma cell line A549-GFP-LUC was injected into nude mice via the left ventricle to construct a bone metastasis model, and was domesticated in vivo for three consecutive times to obtain the human high bone metastasis lung adenocarcinoma cell line A549-GFP-LUC-BM3; cell counting kit-8 (CCK-8), colony formation assay, scratch wound assays, Transwell assay and Western blot were used to compare the proliferation and invasion abilities of A549-GFP-LUC-BM3 with the parental cells. A549-GFP-LUC-BM3 cells and parental cells were further analyzed by transcriptomic sequencing. RESULTS: Human high-bone metastatic lung adenocarcinoma cells A549-GFP-LUC-BM3 was successfully established. Compared to parental cells, this cells exhibited a significantly higher incidence of bone metastasis and enhanced in vitro proliferation, migration, and invasion abilities. Transcriptomic sequencing results revealed that the A549-GFP-LUC-BM3 cell line had 2954 differentially expressed genes compared to the parental cells, with 1021 genes up-regulated and 1933 genes down-regulated. Gene Ontology (GO) functional enrichment analysis indicated that the differentially expressed genes were primarily localized in cellular components such as the cell periphery. The molecular functions identified as significantly enriched included signaling receptor activity, calcium ion binding, and extracellular matrix structural constituent. Additionally, the biological processes found to be enriched were cell adhesion and biological adhesion. The enrichment analysis conducted using the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that the differentially expressed genes were primarily involved in the metabolism of xenobiotics by cytochrome P450, retinol metabolism, drug metabolism-cytochrome P450, cell adhesion molecules, steroid hormone biosynthesis, and the nuclear factor kappa B (NF-κB) signaling pathway. CONCLUSIONS: The highly bone-metastatic human lung adenocarcinoma cell line with GFP and luciferase double labeling was successfully established. The biological behavior and transcriptome sequencing of the cell line suggest that it has a high bone-metastatic potential.