Project description:In metastasis, the existence tumor cells overcoming the immune system during early organ seeding is crucial, yet the dynamics of tumor-immune interactions during micrometastasis remain unclear. Examining the immune selective pressure in breast cancer (BC) mouse models, we unexpectedly found TIM3 among the most upregulated genes in metastatic surviving BC cells. The selection of TIM3+ tumor cells, was specifically occurring during early seeding of micrometastasis, escaping the immune attack and acquiring stemness. Also clinical data confirmed increased TIM3+ tumor cells in BC metastasis. The aim of the study was to understand the mechanistic insgihts of Tim3 in breast cancer cells in vivo to decipher pivotal pathways of Tim3-mediated immun-evasion.
Project description:In this study we describe the immunosupressive role of Tim3+ tumor cells during eraly stages of metastasis. We used single cell RNA sequencing (scRNA-seq) to analyze the diversity of immune cells subsets altered by Tim3 expression in the tumor cells. The aim was to determine the immune status of immunosuppressive and cytotoxic populations during the dynamic process of the metastatic colonization in the liver
Project description:TIM3, a T-cell inhibitory receptor, is expressed on exhausted T cells in tumor microenvironment (TME). Anti-TIM3 antibody therapy could alleviate the suppression of tumor-infiltrating lymphocytes (TILs) in IL-2 dependent fashion. We hypothesize that high expression of TIM3 and limited IL-2 in TME facilitate immune evasion. To test that, we engineered anti-TIM3-pro-IL2 to selectively deliver IL-2 to TIM3high TILs by TIM3 antibody and reduce its toxicity with a cis delivery mechanism. Since IL-2 could reduce its activity at acidic pH inside TME, we also screened a low pH-selective IL-2 mutein (IL2V2) with enhanced affinity for IL-2Rβ. We then integrated pro-IL-2 into the anti-TIM3 antibodies in two different forms: TIM3-Rα-MMPs-IL2V2 (TIM3-ProIL2V2) as IL-2 release-form vs TIM3-IL2V2-MMPs-Rα as cis-form after binding to TIM3high T cells, ensuring the need of targeted delivery to TIM3-expressing TILs. Surprisingly, released IL2V2 from TIM3-Rα-MMPs-IL2V2 proved superior in anti-tumor immunity, but not cis delivery form TIM3-IL2V2-MMPs-Rα. Mechanistically, TIM3-ProIL2V2 not only reactivated TIM3+ TILs but also facilitated the activation and expansion of TIM3- T cells which in turn supported a sustained source of TIM3+ effector. TIM3-ProIL2V2 could control multiple tumor models including human tumor in humanized mice, confirming the hypothesis. TIM3-ProIL2V2 activates and expands TIM3-CD8+ T cells to overcome current major unmet medical need: anti-PD-1/L1 resistance. This strategy illustrates the potential of a tailored, low pH-resistant IL2 variant in invigorating both TIM3-negative and positive CD8+ T cells, offering a promising avenue for treating resistant tumors with reduced toxicity.
Project description:In human breast cancer, mortality is associated with metastasis to distant sites. Therefore, it is critical to elucidate the biological mechanisms that underlie tumor progression and metastasis. Using signaling pathway signatures we previously predicted a role for E2F transcription factors in Myc induced tumors. To test this role we interbred MMTV-Myc transgenic mice with E2F knockouts. Surprisingly, we observed that the loss of E2F2 sharply increased the percentage of lung metastasis in MMTV-Myc transgenic mice. Examining the gene expression profile from these tumors, we identified genetic components that were potentially involved in mediating metastasis. These genes were filtered to uncover the genes involved in metastasis that also impacted distant metastasis free survival in human breast cancer. In order to elucidate the mechanism by which E2F2 loss enhanced metastasis we generated knockdowns of E2F2 in MDA-MB-231 cells and observed increased migration in vitro and increased lung colonization in vivo. We then examined genes that were differentially regulated between tumors from MMTV-Myc, MMTV-Myc E2F2-/-, and lung metastases samples and identified PTPRD. To test the role of PTPRD in E2F2-mediated breast cancer metastasis, we generated a knockdown of PTPRD in MDA-MB-231 cells. We noted that decreased levels of PTPRD resulted in decreased migration in vitro and decreased lung colonization in vivo. Taken together, these data indicate that E2F2 loss results in increased metastasis in breast cancer, potentially functioning through a PTPRD dependent mechanism. Lung metastases from MMTV-Myc tumors in a E2F2 knockout and E2F3 +/- backgrounds were analyzed for their gene expression profile
Project description:Genome-wide analyses have identified thousands of long non-coding RNAs (lncRNAs). Malat1 (Metastasis Associated Lung Adenocarcinoma Transcript 1) is among the most abundant lncRNAs whose expression is altered in numerous cancers. Here we report that genomic loss, as well as systemic knockdown of Malat1 using antisense oligonucleotides, in the MMTV-PyMT mouse mammary carcinoma model results in slower tumor growth accompanied by differentiation into highly cystic tumors and a significant reduction in lung metastasis. Further, Malat1 loss results in a reduction of branching morphogenesis in MMTV-PyMT and Her2/neu amplified tumor organoids consistent with the in vivo reduction in lung metastasis. At the molecular level, Malat1 knockdown results in alterations in gene expression and changes in splicing patterns of genes involved in differentiation and pro-tumorigenic signaling pathways. Together, these data indicate that the lncRNA Malat1 regulates critical processes in mammary cancer pathogenesis and represents a promising therapeutic target for inhibiting breast cancer metastasis. Transcriptome profiles of tumors and organoids after Malat1 knockdown using antisense olgonucleotides (ASOs).
Project description:Preview PDF Abstract Exhaustion represents a collection of programmed T cell differentiation states and an important mode of T cell dysfunction. T cell progression from progenitor to terminal exhaustion is associated with upregulation of the transcription factor TOX and expression of TIM3. Our understanding of factors regulating TOX expression and the transition from progenitor to terminal exhaustion, however, remains incomplete. We reveal here that T cell upregulation of tumor necrosis factor receptor type II (TNFR2) coincides with the gain of phenotypic markers and functions reflective of terminal exhaustion. Meanwhile, knocking out TNFR2 affords a novel population of T cells that express TIM3 but possess diminished TOX levels and functional characteristics of both progenitor and terminally exhausted cells. TIM3+ TNFR2 KO T cells exhibit reduced exhaustion transcriptional programs and enhanced AP1 pathway signatures. Finally, TNFR2 KO mice demonstrate improved T cell-dependent control of tumor and chronic lymphocytic choriomeningitis viral (cLCMV) infection, while pharmacologic antagonism of TNFR2 licenses responses to checkpoint blockade in multiple tumor models.
Project description:In human breast cancer, mortality is associated with metastasis to distant sites. Therefore, it is critical to elucidate the biological mechanisms that underlie tumor progression and metastasis. Using signaling pathway signatures we previously predicted a role for E2F transcription factors in Myc induced tumors. To test this role we interbred MMTV-Myc transgenic mice with E2F knockouts. Surprisingly, we observed that the loss of E2F2 sharply increased the percentage of lung metastasis in MMTV-Myc transgenic mice. Examining the gene expression profile from these tumors, we identified genetic components that were potentially involved in mediating metastasis. These genes were filtered to uncover the genes involved in metastasis that also impacted distant metastasis free survival in human breast cancer. In order to elucidate the mechanism by which E2F2 loss enhanced metastasis we generated knockdowns of E2F2 in MDA-MB-231 cells and observed increased migration in vitro and increased lung colonization in vivo. We then examined genes that were differentially regulated between tumors from MMTV-Myc, MMTV-Myc E2F2-/-, and lung metastases samples and identified PTPRD. To test the role of PTPRD in E2F2-mediated breast cancer metastasis, we generated a knockdown of PTPRD in MDA-MB-231 cells. We noted that decreased levels of PTPRD resulted in decreased migration in vitro and decreased lung colonization in vivo. Taken together, these data indicate that E2F2 loss results in increased metastasis in breast cancer, potentially functioning through a PTPRD dependent mechanism.
Project description:Genome-wide analyses have identified thousands of long non-coding RNAs (lncRNAs). Malat1 (Metastasis Associated Lung Adenocarcinoma Transcript 1) is among the most abundant lncRNAs whose expression is altered in numerous cancers. Here we report that genomic loss, as well as systemic knockdown of Malat1 using antisense oligonucleotides, in the MMTV-PyMT mouse mammary carcinoma model results in slower tumor growth accompanied by differentiation into highly cystic tumors and a significant reduction in lung metastasis. Further, Malat1 loss results in a reduction of branching morphogenesis in MMTV-PyMT and Her2/neu amplified tumor organoids consistent with the in vivo reduction in lung metastasis. At the molecular level, Malat1 knockdown results in alterations in gene expression and changes in splicing patterns of genes involved in differentiation and pro-tumorigenic signaling pathways. Together, these data indicate that the lncRNA Malat1 regulates critical processes in mammary cancer pathogenesis and represents a promising therapeutic target for inhibiting breast cancer metastasis.