Current immunotherapy paradigms aim to reinvigorate CD8
T cells, but the contribution of humoral immunity to antitumor immunity remains understudied. Here, we demonstrate that in head and neck ...squamous cell carcinoma (HNSCC) caused by human papillomavirus infection (HPV
), patients have transcriptional signatures of germinal center (GC) tumor infiltrating B cells (TIL-Bs) and spatial organization of immune cells consistent with tertiary lymphoid structures (TLS) with GCs, both of which correlate with favorable outcome. GC TIL-Bs in HPV
HNSCC are characterized by distinct waves of gene expression consistent with dark zone, light zone and a transitional state of GC B cells. Semaphorin 4a expression is enhanced on GC TIL-Bs present in TLS of HPV
HNSCC and during the differentiation of TIL-Bs. Our study suggests that therapeutics to enhance TIL-B responses in HNSCC should be prioritized in future studies to determine if they can complement current T cell mediated immunotherapies.
Ovarian clear cell carcinoma (OCCC) is a deadly and treatment-resistant cancer, which arises within the unique microenvironment of endometriosis. In this study, we identified a subset of ...endometriosis-derived mesenchymal stem cells (enMSC) characterized by loss of CD10 expression that specifically support OCCC growth. RNA sequencing identified alterations in iron export in CD10-negative enMSCs and reciprocal changes in metal transport in cocultured OCCC cells. CD10-negative enMSCs exhibited elevated expression of iron export proteins hephaestin and ferroportin and donate iron to associated OCCCs, functionally increasing the levels of labile intracellular iron. Iron is necessary for OCCC growth, and CD10-negative enMSCs prevented the growth inhibitory effects of iron chelation. In addition, enMSC-mediated increases in OCCC iron resulted in a unique sensitivity to ferroptosis. In vitro and in vivo, treatment with the ferroptosis inducer erastin resulted in significant death of cancer cells grown with CD10-negative enMSCs. Collectively, this work describes a novel mechanism of stromal-mediated tumor support via iron donation. This work also defines an important role of endometriosis-associated MSCs in supporting OCCC growth and identifies a critical therapeutic vulnerability of OCCC to ferroptosis based on stromal phenotype.
Endometriosis-derived mesenchymal stem cells support ovarian clear cell carcinoma via iron donation necessary for cancer growth, which also confers sensitivity to ferroptosis-inducing therapy.
Ovarian cancer is characterized by early metastatic spread. This study demonstrates that carcinoma-associated mesenchymal stromal cells (CA-MSCs) enhance metastasis by increasing tumor cell ...heterogeneity through mitochondrial donation. CA-MSC mitochondrial donation preferentially occurs in ovarian cancer cells with low levels of mitochondria (“mito poor”). CA-MSC mitochondrial donation rescues the phenotype of mito poor cells, restoring their proliferative capacity, resistance to chemotherapy, and cellular respiration. Receipt of CA-MSC-derived mitochondria induces tumor cell transcriptional changes leading to the secretion of ANGPTL3, which enhances the proliferation of tumor cells without CA-MSC mitochondria, thus amplifying the impact of mitochondrial transfer. Donated CA-MSC mitochondrial DNA persisted in recipient tumor cells for at least 14 days. CA-MSC mitochondrial donation occurs in vivo, enhancing tumor cell heterogeneity and decreasing mouse survival. Collectively, this work identifies CA-MSC mitochondrial transfer as a critical mediator of ovarian cancer cell survival, heterogeneity, and metastasis and presents a unique therapeutic target in ovarian cancer.
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•CA-MSCs donate mitochondria to ovarian cancer cells with low endogenous mitochondria•Mitochondrial donation enhances cancer cell proliferation, chemoresistance, and OXPHOS•Donated mito-to-nuclear signaling drives ANGPTL3 secretion, which increases tumor cell growth•Mito donation enhances metastasis and clonal heterogeneity in vivo
Frisbie et al. demonstrate that stromal-to-tumor cell mitochondrial transfer drives ovarian cancer metastasis and clonal heterogeneity. Carcinoma-associated mesenchymal stem cells donate mitochondria to vulnerable tumor cells, enhancing tumor cell proliferation, chemoresistance, and respiratory capacity and triggering ANGPTL3 secretion to further promote tumor growth. These findings offer a potential therapeutic target for ovarian cancer.
A role for cancer cell epithelial-to-mesenchymal transition (EMT) in cancer is well established. Here, we show that, in addition to cancer cell EMT, ovarian cancer cell metastasis relies on an ...epigenomic mesenchymal-to-epithelial transition (MET) in host mesenchymal stem cells (MSCs). These reprogrammed MSCs, termed carcinoma-associated MSCs (CA-MSCs), acquire pro-tumorigenic functions and directly bind cancer cells to serve as a metastatic driver/chaperone. Cancer cells induce this epigenomic MET characterized by enhancer-enriched DNA hypermethylation, altered chromatin accessibility, and differential histone modifications. This phenomenon appears clinically relevant, as CA-MSC MET is highly correlated with patient survival. Mechanistically, mirroring MET observed in development, MET in CA-MSCs is mediated by WT1 and EZH2. Importantly, EZH2 inhibitors, which are clinically available, significantly inhibited CA-MSC-mediated metastasis in mouse models of ovarian cancer.
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•Ovarian cancer induces an epigenomic MET in CA-MSCs•CA-MSCs enhance metastasis through direct binding to cancer cells and co-metastasis•MET in CA-MSCs is mediated by WT1 and EZH2•CA-MSC MET is clinically significant and correlated with patient survival
Fan et al. demonstrate that ovarian cancer reprograms the epigenome of stromal cells, inducing a mesenchymal-to-epithelial transition (MET) to form carcinoma-associated mesenchymal stem cells (CA-MSCs). This MET, mediated by WT1 and EZH2, enables CA-MSC:cancer cell co-metastasis. EZH2 inhibition decreases CA-MSC-mediated metastasis, presenting a potential therapeutic opportunity in ovarian cancer.
The ability of cancer cells to detach from the primary site and metastasize is the main cause of cancer- related death among all cancer types. Epithelial-to-mesenchymal transition (EMT) is the first ...event of the metastatic cascade, resulting in the loss of cell-cell adhesion and the acquisition of motile and stem-like phenotypes. A critical modulator of EMT in cancer cells is the stromal tumor microenvironment (TME), which can promote the acquisition of a mesenchymal phenotype through direct interaction with cancer cells or changes to the broader microenvironment. In this review, we will explore the role of stromal cells in modulating cancer cell EMT, with particular emphasis on the function of mesenchymal stromal/stem cells (MSCs) through the activation of EMT-inducing pathways, extra cellular matrix (ECM) remodeling, immune cell alteration, and metabolic rewiring.
Ovarian cancer is characterized by early, diffuse metastasis with 70% of women having metastatic disease at the time of diagnosis. While elegant transgenic mouse models of ovarian cancer exist, these ...mice are expensive and take a long time to develop tumors. Intraperitoneal injection xenograft models lack human stroma and do not accurately model ovarian cancer metastasis. Even patient derived xenografts (PDX) do not fully recapitulate the human stromal microenvironment as serial PDX passages demonstrate significant loss of human stroma. The ability to easily model human ovarian cancer within a physiologically relevant stromal microenvironment is an unmet need. Here, the protocol presents an orthotopic ovarian cancer mouse model using human ovarian cancer cells combined with patient-derived carcinoma-associated mesenchymal stem cells (CA-MSCs). CA-MSCs are stromal progenitor cells, which drive the formation of the stromal microenvironment and support ovarian cancer growth and metastasis. This model develops early and diffuses metastasis mimicking clinical presentation. In this model, luciferase expressing ovarian cancer cells are mixed in a 1:1 ratio with CA-MSCs and injected into the ovarian bursa of NSG mice. Tumor growth and metastasis are followed serially over time using bioluminescence imaging. The resulting tumors grow aggressively and form abdominal metastases by 14 days post injection. Mice experienced significant decreases in body weight as a marker of systemic illness and increased disease burden. By day 30 post injection, mice met endpoint criteria of >10% body weight loss and necropsy confirmed intra-abdominal metastasis in 100% of mice and 60%-80% lung and parenchymal liver metastasis. Collectively, orthotopic engraftment of ovarian cancer cells and stroma cells generates tumors that closely mimic the early and diffuse metastatic behavior of human ovarian cancer. Furthermore, this model provides a tool to study the role of ovarian cancer cell: stroma cell interactions in metastatic progression.
Low success rates in oncology drug development are prompting re-evaluation of preclinical models, including orthotopic tumor engraftment. In breast cancer models, tumor cells are typically injected ...into mouse mammary fat pads (MFP). However, this approach bypasses the epithelial microenvironment, potentially altering tumor properties in ways that affect translational application.
Tumors were generated by mammary intraductal (MIND) engraftment of 4T1 carcinoma cells. Growth, histopathology, and molecular features were quantified.
Despite growth similar to that of 4T1 MFP tumors, 4T1 MIND tumors exhibit distinct histopathology and increased metastasis. Furthermore, >6,000 transcripts were found to be uniquely up-regulated in 4T1 MIND tumor cells, including genes that drive several cancer hallmarks, in addition to two known therapeutic targets that were not up-regulated in 4T1 MFP tumor cells.
Engraftment into the epithelial microenvironment generates tumors that more closely recapitulate the complexity of malignancy, suggesting that intraductal adaptation of orthotopic mammary models may be an important step towards improving outcomes in preclinical drug screening and development.
Abstract Endometriosis-associated carcinomas (EACs) and endometrial malignancies have many commonalities yet their pathophysiology, particularly those with high-risk histology such as clear cell, is ...understudied. EACs are histologically and clinically distinct from other gynecological cancers due to their unique origin within endometriosis. The endometriotic microenvironment is uniquely hypoxic with high levels of iron due to recurrent menstrual cycling, and this iron-rich microenvironment has been linked to promoting carcinogenesis through iron-induced oxidative stress. However, the mechanism by which the endometriotic microenvironment contributes to EAC tumorigenesis and how this compares with endometrial cancer is unknown. Most of our current knowledge of EACs is built on either epidemiologic analyses or correlative studies. Additionally, most studies of the endometriotic microenvironment primarily focus on the epithelial component while the role of the stroma has been largely unexplored. Mesenchymal stem cells (MSC) are a critical component of the stromal microenvironment. Recently, we identified a key role of endometriosis derived MSCs (enMSCs) in altering ovarian clear cell carcinoma iron regulation. Interestingly, enMSCs resemble the primary endometrium derived MSCs, which suggested their role in endometrial cancer. This stromal subset is characterized by the loss of surface CD10 expression. It is known that cancer cells, particularly clear cell carcinoma (CCC), have a unique requirement for high levels of iron. We hypothesize that CD10 negative enMSCs promote growth of EAC and endometrial cancer through iron regulation. MSCs were isolated from primary human benign endometriosis, benign endometrium, or endometrial cancer. Flow cytometry was used to measure surface CD10 expression. We investigated the role of CD10 negative enMSCs on CCC iron regulation. Our results showed that CD10 negative enMSCs promote CCC growth by exporting iron through the upregulation of Hephaestin (HEPH) and Ferroportin (FPO) which then led to increase labile iron pool (LIP) in CCC cells. However, increasing the LIP does not occur with iron supplementation alone, this indicates the critical role of CD10 negative enMSCs in regulating iron handling in CCC cells. Additionally, our data showed that CD10 negative enMSCs alter the balance of Ferritin L and Ferritin H- the main iron storage proteins- in CCC cells. Mechanistically, our preliminary data showed that CD10 negative enMSCs directly donate Ferritin L into CCC cells. Further, CD10 negative enMSCs enhance Ferritin H degradation through the upregulation of ferritinophagy in CCC cells. In conclusion, our results indicate there is a sub-population of enMSCs, marked by the loss of CD10 expression, that enhances EAC and endometrial cancer cell growth through iron regulation. This highlights the existence of a tumor-promoting stromal cell within both the endometrium and endometriosis which can be capitalized on as an “Achilles' heel” to uncover novel treatment targets for EAC and endometrial cancer. Citation Format: Huda I. Atiya, Lan G. Coffman. Role of stromal CD10 expression in progression of endometrial and endometriosis-associated cancers abstract. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr A014.
Abstract High grade serous ovarian cancer (HGSOC) is the most common and lethal subtype of ovarian cancer accounting for 80-90% of diagnoses. Despite its high incidence and mortality, the mechanisms ...of cancer initiation are unclear. The majority of HGSOC originates in the fallopian tube epithelium (FTE) with support of underlying mesenchymal stromal/stem cells (MSCs). MSCs are stromal progenitor cells that play important roles in wound healing and, in the context of cancer, tumor progression. We showed that MSCs within the tumor microenvironment, termed cancer associated MSCs (CA-MSCs) harbor a unique, age-associated epigenetic signature that is essential for tumor growth and metastasis. Surprisingly, we identified rare subsets of MSCs from benign tubes that exhibit similar epigenetic changes to cancer educated CA-MSCs suggesting that the pro-oncogenic MSC phenotype exists prior to cancer initiation. These “high risk” MSCs (hrMSCs) increase with age, are enriched in BRCA mutation carrier patients, promote cancer cell proliferation, and most notably, elicit tumor formation in primary, non-cancerous FTE. To elucidate the mechanism of hrMSC-induced malignant transformation of FTE, we characterized the effect that hrMSCs have on primary FTE. HrMSCs promoted increased growth of FTE relative to normal/low risk MSCs (lrMSCs) derived from the same patient. These MSCs lack the epigenetic signature/transcriptome of hrMSCs/CA-MSCs. Intriguingly, we co-cultured FTE with hrMSCs at a 1:1 ratio and discovered robust DNA damage in the form of DNA double strand breaks (53BP1 foci) in FTE at 24 hours. Furthermore, conditioned media from hrMSCs supported the recovery of FTE following damage with other DNA damaging agents. We hypothesize that the DNA damage function of hrMSCs serves as a selective pressure for mutation in FTE (1st hit). Additionally, we hypothesize that hrMSCs simultaneously provide growth signals to FTE allowing for evasion of DNA damage-induced cell death (2nd hit). Lastly, we hypothesize that both hrMSC functions are required for genesis of HGSOC. Citation Format: Geyon L. Garcia, Huda I. Atiya, Lan G. Coffman. Mesenchymal stem cells act as a selective pressure for High Grade Serous Ovarian Cancer initiation abstract. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A058.
Abstract
Ovarian cancer is characterized by early, diffuse metastatic spread with most women presenting with widespread abdominal metastasis at the time of diagnosis. Prior work demonstrates ...carcinoma-associated mesenchymal stem cells (CA-MSCs) enhance ovarian cancer metastasis through a process of direct cellular interaction and formation of heterocellular CA-MSC and tumor cell complexes. Here we demonstrate CA-MSCs enhance metastasis via increasing tumor cell heterogeneity through mitochondrial donation. CA-MSCs directly interact with ovarian cancer cells forming tunneling nanotubules (TNTs). CA-MSCs transfer live mitochondria via these TNTs to ovarian cancer cells. This mitochondrial donation preferentially occurs in ovarian cancer cells with the least endogenous mitochondria (‘mito poor’ cancer cells). Mito poor cancer cells demonstrate decreased proliferation, increased sensitivity to chemotherapy and decreased oxidative phosphorylation compared to ‘mito rich’ cancer cells. CA-MSCs rescue the phenotype of these mito poor cancer cells restoring their proliferative capacity, increasing chemotherapy resistance and increasing oxidative phosphorylation. We validated these findings in a fully autologous system using CA-MSCs and cancer cells derived from the same patient to prevent confounding effects of cellular response to foreign organelle/DNA. Using a knockdown of the mitochondrial motor protein, MIRO1, we demonstrate mitochondrial transfer is necessary for the CA-MSC-mediated rescue of mito poor cancer cells. We developed a haplotype-specific quantification of mitochondrial DNA to differentiate CA-MSC derived mitochondria from endogenous tumor cell mitochondria. We used this system to both quantify the amount of CA-MSC mitochondrial donation and to demonstrate CA-MSC donated mitochondria persist in tumor cells over at least 14 days. Importantly, CA-MSC mitochondrial donation occurs in vivo and is associated with decreased survival in an orthotopic ovarian cancer mouse model. A DNA barcoding system was used to quantify tumor cell clonal heterogeneity. Using this system, we demonstrate CA-MSCs significantly enhance tumor cell heterogeneity, particularly during metastasis. This increase in tumor cell heterogeneity is dependent on CA-MSC mitochondrial transfer. Collectively, we report CA-MSC mitochondrial transfer as a critical mediator of ovarian cancer survival, heterogeneity and metastasis representing a potentially powerful therapeutic target.
Citation Format: Leonard G. Frisbie, Catherine A. Pressimone, Huda I. Atiya, Alexander T. Pearson, Lan G. Coffman. Carcinoma-associated mesenchymal stem cells promote ovarian cancer metastasis by increasing tumor heterogeneity through direct mitochondrial transfer abstract. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR016.
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