Trellis tree-based analysis reveals stromal regulation of patient-derived organoid drug responses.

Patient-derived organoids (PDOs) can model personalized therapy responses; however, current screening technologies cannot reveal drug response mechanisms or how tumor microenvironment cells alter therapeutic performance. To address this, we developed a highly multiplexed mass cytometry platform to measure post-translational modification (PTM) signaling, DNA damage, cell-cycle activity, and apoptosis in >2,500 colorectal cancer (CRC) PDOs and cancer-associated fibroblasts (CAFs) in response to clinical therapies at single-cell resolution. To compare patient- and microenvironment-specific drug responses in thousands of single-cell datasets, we developed "Trellis"-a highly scalable, tree-based treatment effect analysis method. Trellis single-cell screening revealed that on-target cell-cycle blockage and DNA-damage drug effects are common, even in chemorefractory PDOs. However, drug-induced apoptosis is rarer, patient-specific, and aligns with cancer cell PTM signaling. We find that CAFs can regulate PDO plasticity-shifting proliferative colonic stem cells (proCSCs) to slow-cycling revival colonic stem cells (revCSCs) to protect cancer cells from chemotherapy.

Unconventional mechanism of action and resistance to rapalogs in renal cancer.

mTORC1 is aberrantly activated in renal cell carcinoma (RCC) and is targeted by rapalogs. As for other targeted therapies, rapalogs clinical utility is limited by the development of resistance. Resistance often results from target mutation, but mTOR mutations are rarely found in RCC. As in humans, prolonged rapalog treatment of RCC tumorgrafts (TGs) led to resistance. Unexpectedly, explants from resistant tumors became sensitive both in culture and in subsequent transplants in mice. Notably, resistance developed despite persistent mTORC1 inhibition in tumor cells. In contrast, mTORC1 became reactivated in the tumor microenvironment (TME). To test the role of the TME, we engineered immunocompromised recipient mice with a resistance mTOR mutation (S2035T). Interestingly, TGs became resistant to rapalogs in mTORS2035T mice. Resistance occurred despite mTORC1 inhibition in tumor cells and could be induced by coculturing tumor cells with mutant fibroblasts. Thus, enforced mTORC1 activation in the TME is sufficient to confer resistance to rapalogs. These studies highlight the importance of mTORC1 inhibition in nontumor cells for rapalog antitumor activity and provide an explanation for the lack of mTOR resistance mutations in RCC patients.

Lactate supports cell-autonomous ECM production to sustain metastatic behavior in prostate cancer.

Extracellular matrix (ECM) is a major component of the tumor environment, promoting the establishment of a pro-invasive behavior. Such environment is supported by both tumor- and stromal-derived metabolites, particularly lactate. In prostate cancer (PCa), cancer-associated fibroblasts (CAFs) are major contributors of secreted lactate, able to impact on metabolic and transcriptional regulation in cancer cells. Here, we describe a mechanism by which CAF-secreted lactate promotes in PCa cells the expression of genes coding for the collagen family. Lactate-exploiting PCa cells rely on increased α-ketoglutarate (α-KG) which activates the α-KG-dependent collagen prolyl-4-hydroxylase (P4HA1) to support collagen hydroxylation. De novo synthetized collagen plays a signaling role by activating discoidin domain receptor 1 (DDR1), supporting stem-like and invasive features of PCa cells. Inhibition of lactate-induced collagen hydroxylation and DDR1 activation reduces the metastatic colonization of PCa cells. Overall, these results provide a new understanding of the link between collagen remodeling/signaling and the nutrient environment exploited by PCa.

Targeting MFGE8 secreted by cancer-associated fibroblasts blocks angiogenesis and metastasis in esophageal squamous cell carcinoma.

Cancer-associated fibroblasts (CAFs) play vital roles in establishing a suitable tumor microenvironment. In this study, RNA sequencing data revealed that CAFs could promote cell proliferation, angiogenesis, and ECM reconstitution by binding to integrin families and activating PI3K/AKT pathways in esophageal squamous cell carcinoma (ESCC). The secretions of CAFs play an important role in regulating these biological activities. Among these secretions, we found that MFGE8 is specifically secreted by CAFs in ESCC. Additionally, the secreted MFGE8 protein is essential in CAF-regulated vascularization, tumor proliferation, drug resistance, and metastasis. By binding to Integrin αVß3/αVß5 receptors, MFGE8 promotes tumor progression by activating both the PI3K/AKT and ERK/AKT pathways. Interestingly, the biological function of MFGE8 secreted by CAFs fully demonstrated the major role of CAFs in ESCC and its mode of mechanism, showing that MFGE8 could be a driver factor of CAFs in remodeling the tumor environment. In vivo treatment targeting CAFs-secreting MFGE8 or its receptor produced significant inhibitory effects on ESCC growth and metastasis, which provides an approach for the treatment of ESCC.

circNOX4 activates an inflammatory fibroblast niche to promote tumor growth and metastasis in NSCLC via FAP/IL-6 axis.

BACKGROUND: Cancer-associated fibroblasts (CAFs) orchestrate a supportive niche that fuels cancer metastatic development in non-small cell lung cancer (NSCLC). Due to the heterogeneity and plasticity of CAFs, manipulating the activated phenotype of fibroblasts is a promising strategy for cancer therapy. However, the underlying mechanisms of fibroblast activation and phenotype switching that drive metastasis remain elusive. METHODS: The clinical implications of fibroblast activation protein (FAP)-positive CAFs (FAP+CAFs) were evaluated based on tumor specimens from NSCLC patients and bioinformatic analysis of online databases. CAF-specific circular RNAs (circRNAs) were screened by circRNA microarrays of primary human CAFs and matched normal fibroblasts (NFs). Survival analyses were performed to assess the prognostic value of circNOX4 in NSCLC clinical samples. The biological effects of circNOX4 were investigated by gain- and loss-of-function experiments in vitro and in vivo. Fluorescence in situ hybridization, luciferase reporter assays, RNA immunoprecipitation, and miRNA rescue experiments were conducted to elucidate the underlying mechanisms of fibroblast activation. Cytokine antibody array, transwell coculture system, and enzyme-linked immunosorbent assay (ELISA) were performed to investigate the downstream effectors that promote cancer metastasis. RESULTS: FAP+CAFs were significantly enriched in metastatic cancer samples, and their higher abundance was correlated with the worse overall survival in NSCLC patients. A novel CAF-specific circRNA, circNOX4 (hsa_circ_0023988), evoked the phenotypic transition from NFs into CAFs and promoted the migration and invasion of NSCLC in vitro and in vivo. Clinically, circNOX4 correlated with the poor prognosis of advanced NSCLC patients. Mechanistically, circNOX4 upregulated FAP by sponging miR-329-5p, which led to fibroblast activation. Furthermore, the circNOX4/miR-329-5p/FAP axis activated an inflammatory fibroblast niche by preferentially inducing interleukin-6 (IL-6) and eventually promoting NSCLC progression. Disruption of the intercellular circNOX4/IL-6 axis significantly suppressed tumor growth and metastatic colonization in vivo. CONCLUSIONS: Our study reveals a role of the circRNA-induced fibroblast niche in tumor metastasis and highlights that targeting the circNOX4/FAP/IL-6 axis is a promising strategy for the intervention of NSCLC metastasis.

An integrated investigation of sulfotransferases (SULTs) in hepatocellular carcinoma and identification of the role of SULT2A1 on stemness.

The cytosolic sulfotransferases (SULTs) are phase II conjugating enzymes, which are widely expressed in the liver and mainly mediate the sulfation of numerous xenobiotics and endogenous compounds. However, the role of various SULTs genes has not been reported in hepatocellular carcinoma (HCC). This study aims to analyze the expression and potential functional roles of SULTs genes in HCC and to identify the role of SULT2A1 in HCC stemness as well as the possible mechanism. We found that all of the 12 SULTs genes were differentially expressed in HCC. Moreover, clinicopathological features and survival rates were also investigated. Multivariate regression analysis showed that SULT2A1 and SULT1C2 could be used as independent prognostic factors in HCC. SULT1C4, SULT1E1, and SULT2A1 were significantly associated with immune infiltration. SULT2A1 deficiency in HCC promoted chemotherapy resistance and stemness maintenance. Mechanistically, silencing of SULT2A1 activated the AKT signaling pathway, on the one hand, promoted the expression of downstream stemness gene c-Myc, on the other hand, facilitated the NRF2 expression to reduce the accumulation of ROS, and jointly increased HCC stemness. Moreover, knockdown NR1I3 was involved in the transcriptional regulation of SULT2A1 in stemness maintenance. In addition, SULT2A1 knockdown HCC cells promoted the proliferation and activation of hepatic stellate cells (HSCs), thereby exerting a potential stroma remodeling effect. Our study revealed the expression and role of SULTs genes in HCC and identified the contribution of SULT2A1 to the initiation and progression of HCC.

Self-Oxygenated Hydrogel Enhances Immune Cell Response and Infiltration Via Triggering Dual DNA Damage to Activate cGAS-STING and Inhibiting CAFs.

Immune checkpoint inhibitors (ICIs) offer promise in breaking through the treatment and survival dilemma of triple-negative breast cancer (TNBC), yet only immunomodulatory subtype and ≈5% TNBC patients respond as monotherapy due to lack of effector immune cells (internal problem) and physical barrier (external limitation) formed by cancer-associated fibroblasts (CAFs). A hydrogel drug-delivery platform, ALG@TBP-2/Pt(0)/nintedanib (ALG@TPN), is designed to induce strong immune functions and the dual elimination of the internal and external tumor microenvironment (TME). Activated by white light, through type I and II photodynamic therapy (PDT), TBP-2 generates large amounts of reactive oxygen species (ROS) intracellularly, oxidizing mitochondrial DNA (mtDNA). The unique catalase activity of Pt(0) converts endogenous H2O2 to O2, reducing the anoxia-limiting PDT and enhancing ROS generation efficacy. Abundant ROS can oxidize Pt(0) to cytotoxic Pt(II), damaging the nuclear DNA (nDNA). Dual damage to mtDNA and nDNA might bi-directionally activate the cGAS/STING pathway and enhance the immune cell response. Besides, nintedanib demonstrates a significant inhibitory effect on CAFs, weakening the immune barrier and deepening immune cell infiltration. Overall, the study provides a self-oxygenating hydrogel with the "PDT/chemotherapy/anti-CAFs" effect, triggering the cGAS/STING pathway to reshape the TME. Both internal and external interventions increase anti-TNBC immune responses.

Knockout of Shcbp1 sensitizes immunotherapy by regulating α-SMA positive cancer-associated fibroblasts.

The crucial role of cancer-associated fibroblasts (CAFs) in promoting T-cell exclusion has a significant impact on tumor immune evasion and resistance to immunotherapy. Therefore, enhancing T-cell infiltration into solid tumors has emerged as a pivotal area of research. We achieved a conventional knockout of Shcbp1 (Shcbp1-/- ) through CRISPR/Cas9 gene editing and crossed these mice with spontaneous breast cancer MMTV-PyMT mice, resulting in PyMT Shcbp1-/- mice. The different CAF subtypes were detected by flow cytometry analysis (FCA). We evaluated collagen and CAFs levels using Sirius red staining, immunohistochemistry (IHC), and immunofluorescence (IF). Primary tumor cells and CAFs were isolated from both PyMT Shcbp1+/+ and PyMT Shcbp1-/- mice. We analyzed CAFs' proliferation, invasion, migration, apoptosis, and cell cycle. Transwell coculture experiments were performed with primary tumor cells and CAFs to evaluate the role of CAFs in increasing the sensitivity of tumor cells to Erdafitinib. Tumors from PyMT Shcbp1+/+ and PyMT Shcbp1-/- mice were orthotopically transplanted to assess the therapeutic effect of the Erdafitinib and PD-1 combination. CAFs and T-cell infiltration in these tumors were assessed using FCA and IF. Knockout of Shcbp1 leads to a significant reduction in tumor burden, promotes longer survival, and decreases CAFs in MMTV-PyMT. Moreover, knockout of Shcbp1 enhances the sensitivity of Erdafitinib, leading to effective inhibition of CAFs' proliferation and invasion, as well as the induction of apoptosis. Additionally, it results in cell cycle arrest at the G2/M phase in vitro. Meanwhile, Shcbp1-/- CAFs change the sensitivity of Shcbp1-/- tumor cells to Erdafitinib compared to Shcbp1+/+ CAFs. Importantly, knockout of Shcbp1 boosts the effectiveness of Erdafitinib in combination with immune checkpoint blockade therapy by augmenting T-cell infiltration through CAFs regulation in vivo. Our findings demonstrate that knockout of Shcbp1 holds significant potential in enhancing the therapeutic response of Erdafitinib combined with PD-1 antibody treatment, offering promising prospects for future breast cancer therapies.

Cancer-associated fibroblast-secreted FGF7 as an ovarian cancer progression promoter.

BACKGROUND: Ovarian cancer (OC) is distinguished by its aggressive nature and the limited efficacy of current treatment strategies. Recent studies have emphasized the significant role of cancer-associated fibroblasts (CAFs) in OC development and progression. METHODS: Employing sophisticated machine learning techniques on bulk transcriptomic datasets, we identified fibroblast growth factor 7 (FGF7), derived from CAFs, as a potential oncogenic factor. We investigated the relationship between FGF7 expression and various clinical parameters. A series of in vitro experiments were undertaken to evaluate the effect of CAFs-derived FGF7 on OC cell activities, such as proliferation, migration, and invasion. Single-cell transcriptomic analysis was also conducted to elucidate the interaction between FGF7 and its receptor. Detailed mechanistic investigations sought to clarify the pathways through which FGF7 fosters OC progression. RESULTS: Our findings indicate that higher FGF7 levels correlate with advanced tumor stages, increased vascular invasion, and poorer prognosis. CAFs-derived FGF7 significantly enhanced OC cell proliferation, migration, and invasion. Single-cell analysis and in vitro studies revealed that CAFs-derived FGF7 inhibits the ubiquitination and degradation of hypoxia-inducible factor 1 alpha (HIF-1α) via FGFR2 interaction. Activation of the FGF7/HIF-1α pathway resulted in the upregulation of mesenchymal markers and downregulation of epithelial markers. Importantly, in vivo treatment with neutralizing antibodies targeting CAFs-derived FGF7 substantially reduced tumor growth. CONCLUSION: Neutralizing FGF7 in the medium or inhibiting HIF-1α signaling reversed the effects of FGF7-mediated EMT, emphasizing the dependence of FGF7-mediated EMT on HIF-1α activation. These findings suggest that targeting the FGF7/HIF-1α/EMT axis may offer new therapeutic opportunities to intervene in OC progression.

Cancer-associated fibroblasts (CAFs) gene signatures predict outcomes in breast and prostate tumor patients.

BACKGROUND: Over the last two decades, tumor-derived RNA expression signatures have been developed for the two most commonly diagnosed tumors worldwide, namely prostate and breast tumors, in order to improve both outcome prediction and treatment decision-making. In this context, molecular signatures gained by main components of the tumor microenvironment, such as cancer-associated fibroblasts (CAFs), have been explored as prognostic and therapeutic tools. Nevertheless, a deeper understanding of the significance of CAFs-related gene signatures in breast and prostate cancers still remains to be disclosed. METHODS: RNA sequencing technology (RNA-seq) was employed to profile and compare the transcriptome of CAFs isolated from patients affected by breast and prostate tumors. The differentially expressed genes (DEGs) characterizing breast and prostate CAFs were intersected with data from public datasets derived from bulk RNA-seq profiles of breast and prostate tumor patients. Pathway enrichment analyses allowed us to appreciate the biological significance of the DEGs. K-means clustering was applied to construct CAFs-related gene signatures specific for breast and prostate cancer and to stratify independent cohorts of patients into high and low gene expression clusters. Kaplan-Meier survival curves and log-rank tests were employed to predict differences in the outcome parameters of the clusters of patients. Decision-tree analysis was used to validate the clustering results and boosting calculations were then employed to improve the results obtained by the decision-tree algorithm. RESULTS: Data obtained in breast CAFs allowed us to assess a signature that includes 8 genes (ITGA11, THBS1, FN1, EMP1, ITGA2, FYN, SPP1, and EMP2) belonging to pro-metastatic signaling routes, such as the focal adhesion pathway. Survival analyses indicated that the cluster of breast cancer patients showing a high expression of the aforementioned genes displays worse clinical outcomes. Next, we identified a prostate CAFs-related signature that includes 11 genes (IL13RA2, GDF7, IL33, CXCL1, TNFRSF19, CXCL6, LIFR, CXCL5, IL7, TSLP, and TNFSF15) associated with immune responses. A low expression of these genes was predictive of poor survival rates in prostate cancer patients. The results obtained were significantly validated through a two-step approach, based on unsupervised (clustering) and supervised (classification) learning techniques, showing a high prediction accuracy (≥ 90%) in independent RNA-seq cohorts. CONCLUSION: We identified a huge heterogeneity in the transcriptional profile of CAFs derived from breast and prostate tumors. Of note, the two novel CAFs-related gene signatures might be considered as reliable prognostic indicators and valuable biomarkers for a better management of breast and prostate cancer patients.

IL-17A-induced cancer-associated fibroblasts releases CXCL12 to promote lung adenocarcinoma progression via Wnt/ß-Catenin signaling pathway.

BACKGROUND: Cancer-associated fibroblasts (CAFs) and their secretion, C-X-C motif chemokine ligand 12 (CXCL12), play an important role in the development of lung adenocarcinoma (LUAD). Interleukin 17A (IL-17A) is also crucial in regulating tumor progression. Herein, we explored the specific relationships between these two factors and their mechanisms in the progression of LUAD. METHODS: Immunohistochemistry was utilized to assess the differential expression levels of IL-17A and CXCL12 in tumor versus normal tissues of LUAD patients, followed by gene correlation analysis. Cell counting kit-8 (CCK8), wound-healing and transwell assays were performed to investigate the effect of IL-17A on the function of LUAD cells. qPCR, immunofluorescence, immunohistochemistry and western blot analyses were conducted to elucidate the potential mechanism by which IL-17A facilitates the development of LUAD via CXCL12. Male BALB-C nude mice were used to explore the role of IL-17A in subcutaneous LUAD mouse models. RESULTS: Elevated expression levels of IL-17A and CXCL12 were observed in LUAD tissues, exhibiting a positive correlation. Further studies revealed that IL-17A could stimulate CAFs to enhance the release of CXCL12, thereby facilitating the growth, proliferation, and metastasis of LUAD. The binding of CXCL12 to its specific receptor influences the activation of the Wnt/ß-Catenin pathway, which in turn affects the progression of LUAD. In vivo experiments have demonstrated that IL-17A enhances the growth of LUAD tumors by facilitating the secretion of CXCL12. Conversely, inhibiting CXCL12 has been demonstrated to impede tumor growth. CONCLUSIONS: We discovered that IL-17A promotes the release of CAFs-derived CXCL12, which in turn facilitates the development of LUAD via the Wnt/ß-Catenin signaling pathway.

PRRX1-OLR1 axis supports CAFs-mediated lung cancer progression and immune suppression.

OBJECTIVE: To investigate the mechanism by which cancer-associated fibroblasts (CAFs) affect the growth and immune evasion of lung cancer cells. METHODS: Initially, datasets comparing CAFs with normal fibroblasts were downloaded from the GEO dataset GSE48397. Genes with the most significant differential expression were selected and validated using clinical data. Subsequently, CAFs were isolated, and the selected genes were knocked down in CAFs. Co-culture experiments were conducted with H1299 or A549 cells to analyze changes in lung cancer cell growth, migration, and immune evasion in vitro and in vivo. To further elucidate the upstream regulatory mechanism, relevant ChIP-seq data were downloaded from the GEO database, and the regulatory relationships were validated through ChIP-qPCR and luciferase reporter assays. RESULTS: OLR1 was significantly overexpressed in CAFs and strongly correlated with adverse prognosis in lung cancer patients. Knockdown of OLR1 markedly inhibited CAFs' support for the growth and immune evasion of lung cancer cells in vitro and in vivo. ChIP-seq results demonstrated that PRRX1 can promote OLR1 expression by recruiting H3K27ac and H3K4me3, thereby activating CAFs. Knockdown of PRRX1 significantly inhibited CAFs' function, while further overexpression of OLR1 restored CAFs' support for lung cancer cell growth, migration, and immune evasion. CONCLUSION: PRRX1 promotes OLR1 expression by recruiting H3K27ac and H3K4me3, activating CAFs, and thereby promoting the growth, migration, and immune evasion of lung cancer cells.

Influential upregulation of KCNE4: Propelling cancer associated fibroblasts-driven colorectal cancer progression.

BACKGROUND: Colorectal cancer (CRC) is a malignancy of remarkable heterogeneity and heightened morbidity. Cancer associated fibroblasts (CAFs) are abundant in CRC tissues and are essential for CRC growth. Here, we aimed to develop a CAF-related classifier for predicting the prognosis of CRC and identify critical pro-tumorigenic genes in CAFs. METHOD: The mRNA expression and clinical information of CRC samples were sourced from two comprehensive databases, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Using a weighted gene co-expression network analysis (WGCNA) approach, CAF-related genes were identified and a CAF risk signature was developed through the application of univariate analysis and the least absolute shrinkage and selection operator (LASSO) Cox regression model. EdU cell proliferation assay, and transwell assay were performed to detect the oncogenic role of KCNE4 in CAFs. RESULTS: We constructed a prognostic CAF model consisting of two genes (SFRP2 and KCNE4). CRC patients were classified into low- and high-CAF-risk groups using the median CAF risk score, and patients in the high-CAF-risk group had worse prognosis. Meanwhile, a higher risk score for CAFs was associated with greater stromal and CAF infiltrations, as well as higher expression of CAF markers. Furthermore, TIDE analysis indicated that patients with a high CAF risk score are less responsive to immunotherapy. Our further experiments had confirmed the strong correlation between KCNE4 and the malignant phenotypes of CAFs. Moreover, we had shown that KCNE4 could actively promote tumor-promoting phenotypes in CAFs, indicating its critical role in cancer progression. CONCLUSION: The two-gene prognostic CAF signature was constructed and could be reliable for predicting prognosis for CRC patients. Moreover, KCNE4 may be a promising strategy for the development of novel anti-cancer therapeutics specifically directed against CAFs.

Identification of BGN positive fibroblasts as a driving factor for colorectal cancer and development of its related prognostic model combined with machine learning.

BACKGROUND: Numerous studies have indicated that cancer-associated fibroblasts (CAFs) play a crucial role in the progression of colorectal cancer (CRC). However, there are still many unknowns regarding the exact role of CAF subtypes in CRC. METHODS: The data for this study were obtained from bulk, single-cell, and spatial transcriptomic sequencing data. Bioinformatics analysis, in vitro experiments, and machine learning methods were employed to investigate the functional characteristics of CAF subtypes and construct prognostic models. RESULTS: Our study demonstrates that Biglycan (BGN) positive cancer-associated fibroblasts (BGN + Fib) serve as a driver in colorectal cancer (CRC). The proportion of BGN + Fib increases gradually with the progression of CRC, and high infiltration of BGN + Fib is associated with poor prognosis in terms of overall survival (OS) and recurrence-free survival (RFS) in CRC. Downregulation of BGN expression in cancer-associated fibroblasts (CAFs) significantly reduces migration and proliferation of CRC cells. Among 101 combinations of 10 machine learning algorithms, the StepCox[both] + plsRcox combination was utilized to develop a BGN + Fib derived risk signature (BGNFRS). BGNFRS was identified as an independent adverse prognostic factor for CRC OS and RFS, outperforming 92 previously published risk signatures. A Nomogram model constructed based on BGNFRS and clinical-pathological features proved to be a valuable tool for predicting CRC prognosis. CONCLUSION: In summary, our study identified BGN + Fib as drivers of CRC, and the derived BGNFRS was effective in predicting the OS and RFS of CRC patients.

Characterization of gastric cancer-stimulated signaling pathways and function of CTGF in cancer-associated fibroblasts.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment (TME) that play an important role in cancer progression. Although the mechanism by which CAFs promote tumorigenesis has been well investigated, the underlying mechanism of CAFs activation by neighboring cancer cells remains elusive. In this study, we aim to investigate the signaling pathways involved in CAFs activation by gastric cancer cells (GC) and to provide insights into the therapeutic targeting of CAFs for overcoming GC. METHODS: Alteration of receptor tyrosine kinase (RTK) activity in CAFs was analyzed using phospho-RTK array. The expression of CAFs effector genes was determined by RT-qPCR or ELISA. The migration and invasion of GC cells co-cultured with CAFs were examined by transwell migration/invasion assay. RESULTS: We found that conditioned media (CM) from GC cells could activate multiple receptor tyrosine kinase signaling pathways, including ERK, AKT, and STAT3. Phospho-RTK array analysis showed that CM from GC cells activated PDGFR tyrosine phosphorylation, but only AKT activation was PDGFR-dependent. Furthermore, we found that connective tissue growth factor (CTGF), a member of the CCN family, was the most pronouncedly induced CAFs effector gene by GC cells. Knockdown of CTGF impaired the ability of CAFs to promote GC cell migration and invasion. Although the PDGFR-AKT pathway was pronouncedly activated in CAFs stimulated by GC cells, its pharmacological inhibition affected neither CTGF induction nor CAFs-induced GC cell migration. Unexpectedly, the knockdown of SRC and SRC-family kinase inhibitors, dasatinib and saracatinib, significantly impaired CTGF induction in activated CAFs and the migration of GC cells co-cultured with CAFs. SRC inhibitors restored the reduced expression of epithelial markers, E-cadherin and Zonula Occludens-1 (ZO-1), in GC cells co-cultured with CAFs, as well as CAFs-induced aggregate formation in a 3D tumor spheroid model. CONCLUSIONS: This study provides a characterization of the signaling pathways and effector genes involved in CAFs activation, and strategies that could effectively inhibit it in the context of GC. Video Abstract.

IgE-Mediated Cannabis Allergy and Cross-Reactivity Syndromes: A Roadmap for Correct Diagnosis and Management.

PURPOSE OF THE REVIEW: With increased access and decriminalization of cannabis use, cases of IgE-dependent cannabis allergy (CA) and cross-reactivity syndromes have been increasingly reported. However, the exact prevalence of cannabis allergy and associated cross-reactive food syndromes (CAFS) remains unknown and is likely to be underestimated due to a lack of awareness and insufficient knowledge of the subject among health care professionals. Therefore, this practical roadmap aims to familiarize the reader with the early recognition and correct management of IgE-dependent cannabis-related allergies. In order to understand the mechanisms underlying these cross-reactivity syndromes and to enable personalized diagnosis and management, special attention is given to the molecular diagnosis of cannabis-related allergies. RECENT FINDINGS: The predominant signs and symptoms of CA are rhinoconjunctivitis and contact urticaria/angioedema. However, CA can also present as a life-threatening condition. In addition, many patients with CA also have distinct cross-reactivity syndromes, mainly involving fruits, vegetables, nuts and cereals. At present, five allergenic components of Cannabis sativa (Can s); Can s 2 (profilin), Can s 3 (a non-specific lipid protein), Can s 4 (oxygen-evolving enhancer protein 2 oxygen), Can s 5 (the Bet v 1 homologue) and Can s 7 (thaumatin-like protein) have been characterized and indexed in the WHO International Union of Immunological Sciences (IUIS) allergen database. However, neither of them is currently readily available for diagnosis, which generally starts by testing crude extracts of native allergens. The road to a clear understanding of CA and the associated cross-reactive food syndromes (CAFS) is still long and winding, but well worth further exploration.

Exosomal-miR-522-3p derived from cancer-associated fibroblasts accelerates tumor metastasis and angiogenesis via repression bone morphogenetic protein 5 in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a gastrointestinal tract malignancy. Exosomes secreted by cancer-associated fibroblasts (CAFs) are reported to participate in tumor progression by delivering noncoding RNA or small proteins. However, the function of exosomal miR-522-3p in CRC remains unclear. METHODS: CAFs were derived from tumor tissues, and exosomes were identified by western blot or TEM/NTA and originated from CAFs/NFs. The viability, invasion, and migration of HUVECs and CRC cells was examined using MTT, Transwell, and wound healing assays, respectively. The molecular interactions were validated using dual luciferase reporter assay and RIP. Xenograft and lung metastasis mouse models were generated to assess tumor growth and metastasis. RESULTS: Exosomes extracted from CAFs/NFs showed high expression of CD63, CD81, and TSG101. CAF-derived exosomes significantly increased the viability, angiogenesis, invasion, and migration of HUVECs and CRC cells, thereby aggravating tumor growth, invasion, and angiogenesis in vivo. miR-522-3p was upregulated in CAF-derived exosomes and CRC tissues. Depletion of miR-522-3p reversed the effect of exosomes derived from CAFs in migration, angiogenesis, and invasion of HUVECs and CRC cells. Furthermore, bone morphogenetic protein 5 (BMP5) was identified as a target gene of miR-522-3p, and upregulation of BMP5 reversed the promoting effect of miR-522-3p mimics or CAF-derived exosomes on cell invasion, migration, and angiogenesis of HUVECs and CRC cells. CONCLUSION: Exosomal miR-522-3p from CAFs promoted the growth and metastasis of CRC through downregulating BMP5, which might provide new strategies for the treatment of CRC.

CXCR4-modified CAR-T cells suppresses MDSCs recruitment via STAT3/NF-κB/SDF-1α axis to enhance efficacy against pancreatic cancer.

Claudin18.2 (CLDN18.2)-specific chimeric antigen receptor (CAR-T) cells displayed limited efficacy in CLDN18.2-positive pancreatic ductal adenocarcinoma (PDAC). Strategies are needed to improve the trafficking capacity of CLDN18.2-specific CAR-T cells. PDAC has a unique microenvironment that consists of abundant cancer-associated fibroblasts (CAFs), which could secrete stromal cell-derived factor 1α (SDF-1α), the ligand of CXCR4. Then, we constructed and explored CLDN18.2-targeted CAR-T cells with CXCR4 co-expression in treating immunocompetent mouse models of PDAC. The results indicated that CXCR4 could promote the infiltration of CAR-T cells and enhance their efficacy in vivo. Mechanistically, the activation of signal transducer and activator of transcription 3 (STAT3) signaling was impaired in CXCR4 CAR-T cells, which reduced the release of inflammatory factors, such as tumor necrosis factor-α, IL-6, and IL-17A. Then, the lower release of inflammatory factors suppressed SDF-1α secretion in CAFs via the nuclear factor κB (NF-κB) pathway. Therefore, the decreased secretion of SDF-1α in feedback decreased the migration of myeloid-derived suppressor cells (MDSCs) in tumor sites. Overall, our study demonstrated that CXCR4 CAR-T cells could traffic more into tumor sites and also suppress MDSC migration via the STAT3/NF-κB/SDF-1α axis to obtain better efficacy in treating CLDN18.2-positive pancreatic cancer. Our findings provide a theoretical rationale for CXCR4 CAR-T cell therapy in PDAC.

CAFs-Associated Genes (CAFGs) in Pancreatic Ductal Adenocarcinoma (PDAC) and Novel Therapeutic Strategy.

Pancreatic ductal adenocarcinoma (PDAC) is the most aggressive cancer with striking fibrosis, and its mortality rate is ranked second across human cancers. Cancer-associated fibroblasts (CAFs) play a critical role in PDAC progression, and we reviewed the molecular understanding of PDAC CAFs and novel therapeutic potential at present. CAFs-associated genes (CAFGs) were tentatively classified into three categories by stroma specificity representing stroma/epithelia expression ratios (SE ratios). The recent classification using single cell transcriptome technology clarified that CAFs were composed of myofibroblasts (myCAFs), inflammatory CAFs (iCAFs), and other minor ones (e.g., POSTN-CAFs and antigen presenting CAFs, apCAFs). LRRC15 is a myCAFs marker, and myCAFs depletion by diphtheria toxin induces the rapid accumulation of cytotoxic T lymphocytes (CTLs) and therefore augment PDL1 antibody treatments. This finding proposes that myCAFs may be a critical regulator of tumor immunity in terms of PDAC progression. myCAFs are located in CAFs adjacent to tumor cells, while iCAFs marked by PDPN and/or COL14A1 are distant from tumor cells, where hypoxic and acidic environments being located in iCAFs putatively due to poor blood supply is consistent with HIF1A and GPR68 expressions. iCAFs may be shared with SASP (secretion-associated phenotypes) in senescent CAFs. myCAFs are classically characterized by CAFGs induced by TGFB1, while chemoresistant CAFs with SASP may dependent on IL6 expression and accompanied by STAT3 activation. Recently, it was found that the unique metabolism of CAFs can be targeted to prevent PDAC progression, where PDAC cells utilize glucose, whereas CAFs in turn utilize lactate, which may be epigenetically regulated, mediated by its target genes including CXCR4. In summary, CAFs have unique molecular characteristics, which have been rigorously clarified as novel therapeutic targets of PDAC progression.

Biomarkers Identification in the Microenvironment of Oral Squamous Cell Carcinoma: A Systematic Review of Proteomic Studies.

An important determinant for oral squamous cell carcinoma (OSCC) onset and outcome is the composition of the tumor microenvironment (TME). Thus, the study of the interactions occurring among cancer cells, immune cells, and cancer-associated fibroblasts within the TME could facilitate the understanding of the mechanisms underlying OSCC development and progression, as well as of its sensitivity or resistance to the therapy. In this context, it must be highlighted that the characterization of TME proteins is enabled by proteomic methodologies, particularly mass spectrometry (MS). Aiming to identify TME protein markers employable for diagnosing and prognosticating OSCC, we have retrieved a total of 119 articles spanning 2001 to 2023, of which 17 have passed the selection process, satisfying all its criteria. We have found a total of 570 proteins detected by MS-based proteomics in the TME of OSCC; among them, 542 are identified by a single study, while 28 are cited by two or more studies. These 28 proteins participate in extracellular matrix remodeling and/or energy metabolism. Here, we propose them as markers that could be used to characterize the TME of OSCC for diagnostic/prognostic purposes. Noteworthy, most of the 28 individuated proteins share one feature: being modulated by the hypoxia that is present in the proliferating OSCC mass.