技术资料

Lung cancer is the leading cause of cancer death in the world today and is poised to claim approximately 1 billion lives during the 21st century. A major challenge in treating this and other cancers is the intrinsic resistance to conventional therapies demonstrated by the stem/progenitor cell that is responsible for the sustained growth,survival,and invasion of the tumor. Identifying these stem cells in lung cancer and defining the biologic processes necessary for their existence is paramount in developing new clinical approaches with the goal of preventing disease recurrence. This review summarizes our understanding of the cellular and molecular mechanisms operating within the putative cancer-initiating cell at the core of lung neoplasia. View Publication

The recent identification of cancer stem cells (CSCs) in multiple human cancers provides a new inroad to understanding tumorigenesis at the cellular level. CSCs are defined by their characteristics of self-renewal,multipotentiality,and tumor initiation upon transplantation. By testing for these defining characteristics,we provide evidence for the existence of CSCs in a transgenic mouse model of glioma,S100beta-verbB;Trp53. In this glioma model,CSCs are enriched in the side population (SP) cells. These SP cells have enhanced tumor-initiating capacity,self-renewal,and multipotentiality compared with non-SP cells from the same tumors. Furthermore,gene expression analysis comparing fluorescence-activated cell sorting-sorted cancer SP cells to non-SP cancer cells and normal neural SP cells identified 45 candidate genes that are differentially expressed in glioma stem cells. We validated the expression of two genes from this list (S100a4 and S100a6) in primary mouse gliomas and human glioma samples. Analyses of xenografted human glioblastoma multiforme cell lines and primary human glioma tissues show that S100A4 and S100A6 are expressed in a small subset of cancer cells and that their abundance is positively correlated to tumor grade. In conclusion,this study shows that CSCs exist in a mouse glioma model,suggesting that this model can be used to study the molecular and cellular characteristics of CSCs in vivo and to further test the CSC hypothesis. View Publication

The majority of BRCA1-associated breast cancers are basal cell-like,which is associated with a poor outcome. Using a spontaneous mouse mammary tumor model,we show that platinum compounds,which generate DNA breaks during the repair process,are more effective than doxorubicin in Brca1/p53-mutated tumors. At 0.5 mg/kg of daily cisplatin treatment,80% primary tumors (n = 8) show complete pathologic response. At greater dosages,100% show complete response (n = 19). However,after 2 to 3 months of complete remission following platinum treatment,tumors relapse and become refractory to successive rounds of treatment. Approximately 3.8% to 8.0% (mean,5.9%) of tumor cells express the normal mammary stem cell markers,CD29(hi)24(med),and these cells are tumorigenic,whereas CD29(med)24(-/lo) and CD29(med)24(hi) cells have diminished tumorigenicity or are nontumorigenic,respectively. In partially platinum-responsive primary transplants,6.6% to 11.0% (mean,8.8%) tumor cells are CD29(hi)24(med); these populations significantly increase to 16.5% to 29.2% (mean,22.8%; P textless 0.05) in platinum-refractory secondary tumor transplants. Further,refractory tumor cells have greater colony-forming ability than the primary transplant-derived cells in the presence of cisplatin. Expression of a normal stem cell marker,Nanog,is decreased in the CD29(hi)24(med) populations in the secondary transplants. Top2A expression is also down-regulated in secondary drug-resistant tumor populations and,in one case,was accompanied by genomic deletion of Top2A. These studies identify distinct cancer cell populations for therapeutic targeting in breast cancer and implicate clonal evolution and expansion of cancer stem-like cells as a potential cause of chemoresistance. View Publication

The concept of cancer stem cells (CSC) embodies two aspects: the stem cell as the initial target of the oncogenic process and the existence of two populations of cells in cancers: the CSC and derived cells. The second is discussed in this review. CSC are defined as cells having three properties: a selectively endowed tumorigenic capacity,an ability to recreate the full repertoire of cancer cells of the parent tumor and the expression of a distinctive repertoire of surface biomarkers. In operational terms,the CSC are among all cancer cells those able to initiate a xenotransplant. Other explicit or implicit assumptions exist,including the concept of CSC as a single unique infrequent population of cells. To avoid such assumptions,we propose to use the operational term tumor-propagating cells (TPC); indeed,the cells that initiate transplants did not initiate the cancer. The experimental evidence supporting the explicit definition is analyzed. Cancers indeed contain a fraction of cells mainly responsible for the tumor development. However,there is evidence that these cells do not represent one homogenous population. Moreover,there is no evidence that the derived cells result from an asymmetric,qualitative and irreversible process. A more general model is proposed of which the CSC model could be one extreme case. We propose that the TPC are multiple evolutionary selected cancer cells with the most competitive properties [maintained by (epi-)genetic mechanisms],at least partially reversible,quantitative rather than qualitative and resulting from a stochastic rather than deterministic process. View Publication

Cancer in humans is the result of a multi-step process. This process often involves the activation of oncogenes and/or the inactivation of tumor suppressor genes. These two steps arise not only due to mutations,but can also be the result of a translocation or an altered transcription rate. One important mechanism is the occurrence of epigenetic alterations like promotor methylation (which may lead to tumor suppressor silencing) or decreased histone acetylation (which can result in the downregulation of proteins involved in apoptosis). Today,histone acetylation and DNA methylation are epigenetic modifications which have been linked closely to the pathology of human cancers and inhibitors of both enzyme classes for clinical use are at hand. In contrast,other fields of epigenetics still lack of similarly thorough knowledge. This is especially true for the group of histone methyltransferases and their inhibitors. Since connections between histone methylation patterns and cancer progression have been recognized,histone methyltransferases represent promising targets for future cancer treatment. View Publication

Targeted therapy interventions using tyrosine kinase inhibitors (TKIs) provide encouraging treatment responses in patients with ALK -rearranged lung adenocarcinomas,yet resistance occurs almost inevitably. In addition to tumor cell-intrinsic resistance mechanisms,accumulating evidence suggests that cancer-associated fibroblasts (CAFs) within the tumor microenvironment contribute to therapy resistance. This study aimed to investigate CAF-driven molecular networks that shape the therapeutic susceptibility of ALK -driven lung adenocarcinoma cells. Three-dimensional (3D) spheroid co-cultures comprising ALK -rearranged lung adenocarcinoma cells and CAFs were utilized to model the tumor microenvironment. Single-cell RNA sequencing was performed to uncover transcriptional differences between TKI-treated homotypic and heterotypic spheroids. Functional assays assessed the effects of CAF-conditioned medium and CAF-secreted factors on tumor cell survival,proliferation,lipid metabolism,and downstream AKT signaling. The therapeutic potential of targeting metabolic vulnerabilities was evaluated using pharmacological inhibition of lipid metabolism and by ferroptosis induction. CAFs significantly diminished the apoptotic response of lung tumor cells to ALK inhibitors while simultaneously enhancing their proliferative capacity. Single-cell RNA sequencing identified lipogenesis-associated genes as a key transcriptional difference between TKI-treated homotypic and heterotypic lung tumor spheroids. CAF-conditioned medium and the CAF-secreted factors HGF and NRG1 activated AKT signaling in 3D-cultured ALK-rearranged lung tumor cells,leading to increased de novo lipogenesis and suppression of lipid peroxidation. These metabolic adaptations were critical for promoting tumor cell survival and fostering therapy resistance. Notably,both dual inhibition of ALK and the lipid-regulatory factor SREBP-1,as well as co-treatment with ferroptosis inducers such as erastin or RSL3,effectively disrupted the CAF-driven metabolic-supportive niche and restored sensitivity of resistant lung tumor spheroids to ALK inhibition. This study highlights a critical role for CAFs in mediating resistance to ALK-TKIs by reprogramming lipid metabolism in ALK-rearranged lung cancer cells. It suggests that targeting these metabolic vulnerabilities,particularly through inhibition of lipid metabolism or induction of ferroptosis,could provide a novel therapeutic approach to overcome resistance and improve patient outcomes. The online version contains supplementary material available at 10.1186/s40170-025-00400-7. View Publication

Cancer stem cells (CSCs) are a promising target for treating cancer,yet how CSC plasticity is maintained in vivo is unclear and is difficult to study in vitro. Here we establish a sustainable primary culture of Oct3/4(+)/Nanog(+) lung CSCs fed with CD90(+) cancer-associated fibroblasts (CAFs) to further advance our knowledge of preserving stem cells in the tumour microenvironment. Using transcriptomics we identify the paracrine network by which CAFs enrich CSCs through de-differentiation and reacquisition of stem cell-like properties. Specifically,we find that IGF1R signalling activation in cancer cells in the presence of CAFs expressing IGF-II can induce Nanog expression and promote stemness. Moreover,this paracrine signalling predicts overall and relapse-free survival in stage I non-small cell lung cancer (NSCLC) patients. IGF-II/IGF1R signalling blockade inhibits Nanog expression and attenuates cancer stem cell features. Our data demonstrate that CAFs constitute a supporting niche for cancer stemness,and targeting this paracrine signalling may present a new therapeutic strategy for NSCLC. View Publication

UNLABELLED Immune-checkpoint blockade (ICB) promotes antitumor immune responses and can result in durable patient benefit. However,response rates in breast cancer patients remain modest,stimulating efforts to discover novel treatment options. Cancer-associated fibroblasts (CAF) represent a major component of the breast tumor microenvironment and have known immunosuppressive functions in addition to their well-established roles in directly promoting tumor growth and metastasis. Here we utilized paired syngeneic mouse mammary carcinoma models to show that CAF abundance is associated with insensitivity to combination $\alpha$CTLA4 and $\alpha$PD-L1 ICB. CAF-rich tumors exhibited an immunologically cold tumor microenvironment,with transcriptomic,flow cytometric,and quantitative histopathologic analyses demonstrating a relationship between CAF density and a CD8+ T-cell-excluded tumor phenotype. The CAF receptor Endo180 (Mrc2) is predominantly expressed on myofibroblastic CAFs,and its genetic deletion depleted a subset of $\alpha$SMA-expressing CAFs and impaired tumor progression in vivo. The addition of wild-type,but not Endo180-deficient,CAFs in coimplantation studies restricted CD8+ T-cell intratumoral infiltration,and tumors in Endo180 knockout mice exhibited increased CD8+ T-cell infiltration and enhanced sensitivity to ICB compared with tumors in wild-type mice. Clinically,in a trial of melanoma patients,high MRC2 mRNA levels in tumors were associated with a poor response to $\alpha$PD-1 therapy,highlighting the potential benefits of therapeutically targeting a specific CAF subpopulation in breast and other CAF-rich cancers to improve clinical responses to immunotherapy. SIGNIFICANCE Paired syngeneic models help unravel the interplay between CAF and tumor immune evasion,highlighting the benefits of targeting fibroblast subpopulations to improve clinical responses to immunotherapy. View Publication

Lysophosphatidic acid (LPA) is enriched in ascites of ovarian cancer patients and is involved in growth and invasion of ovarian cancer cells. Accumulating evidence suggests cancer-associated myofibroblasts play a pivotal role in tumorigenesis through secreting stromal cell-derived factor-1 (SDF-1). In the present study,we demonstrate that LPA induces expression of alpha-smooth muscle actin (alpha-SMA),a marker for myofibroblasts,in human adipose tissue-derived mesenchymal stem cells (hADSCs). The LPA-induced expression of alpha-SMA was completely abrogated by pretreatment of the cells with Ki16425,an antagonist of LPA receptors,or by silencing LPA(1) or LPA(2) isoform expression with small interference RNA (siRNA). LPA elicited phosphorylation of Smad2/3,and siRNA-mediated depletion of endogenous Smad2/3 or adenoviral expression of Smad7,an inhibitory Smad,abrogated the LPA induced expression of alpha-SMA and phosphorylation of Smad2/3. LPA-induced secretion of transforming growth factor (TGF)-beta1 in hADSCs,and pretreatment of the cells with SB431542,a TGF-beta type I receptor kinase inhibitor,or anti-TGF-beta1 neutralizing antibody inhibited the LPA-induced expression of alpha-SMA and phosphorylation of Smad2. Furthermore,ascites from ovarian cancer patients or conditioned medium from ovarian cancer cells induced expression of alpha-SMA and phosphorylation of Smad2,and pretreatment of the cells with Ki16425 or SB431542 abrogated the expression of alpha-SMA and phosphorylation of Smad2. In addition,LPA increased the expression of SDF-1 in hADSCs,and pretreatment of the cells with Ki16425 or SB431562 attenuated the LPA-stimulated expression of SDF-1. These results suggest that cancer-derived LPA stimulates differentiation of hADSCs to myofibroblast-like cells and increases SDF-1 expression through activating autocrine TGF-beta1-Smad signaling pathway. View Publication

Cancer-initiating cells (CICs) that are responsible for tumor initiation,propagation,and resistance to standard therapies have been isolated from human solid tumors,including colorectal cancer (CRC). The aim of this study was to obtain an immunological profile of CRC-derived CICs and to identify CIC-associated target molecules for T cell immunotherapy. We have isolated cells with CIC properties along with their putative non-CIC autologous counterparts from human primary CRC tissues. These CICs have been shown to display tumor-initiating/stemness" properties� View Publication

Endocannabinoids are arachidonic acid derivatives and part of a novel bioactive lipid signaling system,along with their G-coupled cannabinoid receptors (CB�? and CB₂) and the enzymes involved in their biosynthesis and degradation. However,their roles in hematopoiesis and hematopoietic stem and progenitor cell (HSPC) functions are not well characterized. Here,we show that bone marrow stromal cells express endocannabinoids (anandamide and 2-arachidonylglycerol),whereas CB₂ receptors are expressed in human and murine HSPCs. On ligand stimulation with CB₂ agonists,CB₂ receptors induced chemotaxis,migration,and enhanced colony formation of bone marrow cells,which were mediated via ERK,PI3-kinase,and Gαi-Rac1 pathways. In vivo,the CB₂ agonist AM1241 induced mobilization of murine HSPCs with short- and long-term repopulating abilities. In addition,granulocyte colony-stimulating factor -induced mobilization of HSPCs was significantly decreased by specific CB₂ antagonists and was impaired in Cnr2(-/-) cannabinoid type 2 receptor knockout mice. Taken together,these results demonstrate that the endocannabinoid system is involved in hematopoiesis and that CB₂/CB₂ agonist axis mediates repopulation of hematopoiesis and mobilization of HSPCs. Thus,CB₂ agonists may be therapeutically applied in clinical conditions,such as bone marrow transplantation. View Publication

Tumor-initiating cells (TICs) are a sub-population of cells that exhibit a robust ability to self-renew and contribute to the formation of primary tumors,the relapse of previously treated tumors and the development of metastases. TICs have been identified in various tumors including those of the breast,and are particularly enriched in the basal-like and claudin-low subtypes of breast cancer. The signaling pathways that contribute to the function and maintenance of TICs are under intense study. We explored the potential involvement of the nuclear factor-$$B (NF-$$B) family of transcription factors in TICs in cell lines that are representative of basal-like and claudin-low breast cancer. NF-$$B was found to be activated in breast cancer cells that form tumorspheres efficiently. Moreover,both canonical and non-canonical NF-$$B signaling is required for these cells to self-renew in vitro and to form xenograft tumors efficiently in vivo using limiting dilutions of cells. Consistent with this fact,canonical and non-canonical NF-$$B signaling is activated in TICs isolated from breast cancer cell lines. Experimental results indicate that NF-$$B promotes the function of TICs by stimulating epithelial-to-mesenchymal transition and by upregulating the expression of the inflammatory cytokines interleukin-1$$ and interleukin-6. The results suggest the use of NF-$$B inhibitors for clinical therapy of certain breast cancers. View Publication