Abhinav Joshi, Li Dai, Marisa Maisiak, Sunmin Lee, Elizabeth Lopez, Takeshi Ito, Len Neckers
{"title":"Mitochondrial HSP90 paralog TRAP1 deletion drives glutamine addiction in tumor cells via destablization of the Cys/Glu antiporter SLC7A11/xCT.","authors":"Abhinav Joshi, Li Dai, Marisa Maisiak, Sunmin Lee, Elizabeth Lopez, Takeshi Ito, Len Neckers","doi":"10.1158/1541-7786.MCR-24-0194","DOIUrl":"https://doi.org/10.1158/1541-7786.MCR-24-0194","url":null,"abstract":"<p><p>TRAP1, the mitochondrial isoform of HSP90, has emerged as a key regulator of cancer cell metabolism, yet the mechanisms by which it rewires nutrient utilization remain poorly understood. We previously reported that TRAP1 loss increases glutamine dependency of mitochondrial respiration following glucose withdrawal. Here, we investigate how TRAP1 deletion impacts glucose metabolism and the mechanisms enabling glutamine retention to support mitochondrial respiration via reductive carboxylation and the oxidative TCA cycle. TRAP1 knockout (KO) in bladder and prostate cancer cells recapitulates the carbon source-specific metabolic rewiring previously observed. Stable isotope tracing reveals that although glucose oxidation remains functional, TRAP1 KO reduces overall glucose uptake and its contribution to glycolysis and the pentose phosphate pathway. This effect is consistent across multiple cell lines. Concurrently, TRAP1-deficient cells exhibit increased glutamine retention and reliance, potentially due to downregulation of the cystine/glutamate antiporter SLC7A11/xCT. Supporting this, xCT overexpression reduces glutamine-dependent respiration in TRAP1 KO cells. qPCR and proteasome inhibition assays suggest xCT is regulated post-translationally via protein stability. Notably, xCT suppression does not trigger ferroptosis, indicating a selective adaptation rather than induction of cell death. Together, our findings suggest that TRAP1 loss decreases glucose uptake while preserving its metabolic fate, promoting glutamine conservation through xCT downregulation to maintain mitochondrial respiration without inducing ferroptosis. Implications: These results reveal a TRAP1-dependent mechanism of metabolic rewiring in cancer cells and identify xCT-mediated glutamine conservation as a key adaptive response, underscoring TRAP1 as a potential metabolic vulnerability and therapeutic target in tumors with altered nutrient utilization.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144079249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"IL-9 promotes migratory dissemination of malignant T-cells by activating the HIF-1α-Cofilin-1 axis in cutaneous T-cell lymphoma.","authors":"Ditipriya Mukherjee, Soumitra Marathe, Diksha Attrish, Vinanti Sawant, Bhavuk Dhamija, Sushant Kumar, Siddhi Wad, Moumita Basu, Neha Sharma, Hasmukh Jain, Steven R Barthel, Rahul Purwar","doi":"10.1158/1541-7786.MCR-24-1020","DOIUrl":"https://doi.org/10.1158/1541-7786.MCR-24-1020","url":null,"abstract":"<p><p>Cutaneous T-cell Lymphoma (CTCL) is a multistage disease characterized by rapid dissemination of malignant T lymphocytes from skin lesions to visceral organs and bone marrow. The cytokine IL-9 and its receptor (IL-9R) are aberrantly overexpressed in CTCL lesions and function to enhance tumor cell survival. Here, we uncovered a critical new role for IL-9 as a potent inducer of migration of malignant T-cells. Stimulation of IL-9R-expressing T-cell lymphoma cells with IL-9 induced a pseudohypoxic cellular state by elevating downstream levels of the pro-migratory and oxygen-sensing transcription factor, hypoxia inducible factor (HIF)-1α. High-throughput quantitative proteomics analyses of pseudohypoxic malignant T-cells identified the actin-modulating protein, Cofilin-1, as a pro-migratory CTCL-intrinsic target downstream of IL-9-HIF-1α signaling. Consistently, multicolor immunofluorescence staining revealed marked co-expression of Cofilin-1 with HIF-1α in both IL-9-treated human lymphoma cell lines and in patient CTCL skin biopsies compared to normal controls. Genetic knockdown of IL-9R or HIF-1α in human T-cell lymphoma lines by RNA interference significantly reduced both HIF-1α and Cofilin-1 co-expression and reversed IL-9-induced migration. Finally, pharmacological antagonism of HIF-1α activity using the FDA-designated orphan drug, echinomycin, significantly abrogated IL-9-triggered migration of both malignant T-cell lines as well as patient-derived T-cell lymphoma cells from CTCL biospecimens. Implications: Our results uncover a CTCL-intrinsic IL-9-HIF-1α-Cofilin-1 axis as a critical promoter of malignant T-cell migration. They further identify HIF-1α and Cofilin-1 as promising therapeutic targets to mitigate IL-9-induced CTCL dissemination.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143991169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Novel metastasis suppressor PI3KC2β is mediated by mTORC1 signalling in breast cancer.","authors":"Kanakaraju Manupati, Mingang Hao, Suhua Li, Sushma Maharjan, Jun-Lin Guan","doi":"10.1158/1541-7786.MCR-24-1045","DOIUrl":"https://doi.org/10.1158/1541-7786.MCR-24-1045","url":null,"abstract":"<p><p>HER2 amplification or mutation accounts for 25% of breast cancer patients that can advance to metastatic disease. Therefore, it is important to identify novel genes which mediate metastasis in HER2+ breast cancer. Here, we describe a new metastatic suppressor gene, Class II phosphatidylinositol 3-kinases (Pik3c2b), by in vivo CRISPR-Cas9 library screening of a custom designed library targeting genes implicated in autophagy using murine HER2+ breast cancer (N418) cells. We further showed that PI3KC2β KO N418 cells increased their migration and invasion in vitro, and lung metastasis in both spontaneous and experimental metastasis assays in vivo. Analysis of breast cancer patient database and tissue samples correlated lower expression of PI3KC2β with decreased metastasis, overall and relapse-free survival. Further, PI3KC2β deletion induced activation of mTORC1 signalling, independent of affecting its kinase activity. Mechanistically, we found that PI3KC2β forms a complex with ITSN1 and raptor that could decreasing stability of raptor, and deletion of either PI3KC2β or ITSN1 led to increased raptor levels and mTORC1 signalling. Lastly, rapamycin treatment reduced migration and invasion of PI3KC2β KO tumor cells in vitro and their lung metastasis in vivo, supporting an important role of mTORC1 pathway. Together, our results identify PI3KC2β as a suppressor for HER2+ breast cancer metastasis by negatively regulating mTORC1 signalling by affecting its complex formation with ITSN1 and raptor. Implications: Our findings revealed PI3KC2β as a new metastasis suppressor for HER2+ breast cancer, which might serve as a potential diagnostic and therapeutic target for the disease.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143991171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Trisiani Affandi, Angela M Ohm, Jordan T Speidel, M Cecilia Caino, Dillon P Boulton, Mary E Reyland
{"title":"PKCδ regulates DNA damage and cell death through a SIRT6/Nrf2-dependent antioxidant response.","authors":"Trisiani Affandi, Angela M Ohm, Jordan T Speidel, M Cecilia Caino, Dillon P Boulton, Mary E Reyland","doi":"10.1158/1541-7786.MCR-24-0805","DOIUrl":"https://doi.org/10.1158/1541-7786.MCR-24-0805","url":null,"abstract":"<p><p>Protein kinase C delta (PKCδ) regulates DNA repair and apoptosis, and inhibition of PKCδ provides robust radioprotection. Here we show that depletion of PKCδ increases mitochondrial ROS production and induces an endogenous antioxidant response through Nrf2, resulting in decreased basal and irradiation-induced DNA damage and cell death. Radioprotection by PKCδ depletion can be reversed with the free radical scavenger, N-acetyl-L-cysteine, indicating an essential role for the antioxidant response. While mitochondrial mass and membrane potential are increased in PKCδ-depleted cells, oxidative phosphorylation and the activity of electron transport chain (ETC) Complex I and Complex III are reduced, suggesting that ETC dysfunction is the source of the increased mitochondrial ROS. The antioxidant response induced by PKCδ depletion is mediated through Sirtuin 6 (SIRT6) and Nrf2. Increased mitochondrial ROS and Nrf2 activation are reversed in PKCδ/SIRT6 double knockdown cells, indicating a central role for SIRT6 in PKCδ-regulated DNA repair and cell death. Regulation of the endogenous antioxidant state through manipulation of the PKCδ/SIRT6 signaling pathway may be a novel clinical approach for protection of healthy tissues in patients undergoing irradiation therapy. Implications: Regulation of the endogenous antioxidant state through manipulation of the PKCδ/SIRT6 signaling pathway may be a novel clinical approach for protection of healthy tissues in patients undergoing irradiation therapy.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144005819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"METTL3 promotes gastric cancer progression via modulation of FNTA-mediated KRAS/ERK signaling activation.","authors":"Fangqi Hu, Song Zhang, Jie Chai","doi":"10.1158/1541-7786.MCR-24-1168","DOIUrl":"https://doi.org/10.1158/1541-7786.MCR-24-1168","url":null,"abstract":"<p><p>As a vital form of post-transcriptional modification, RNA N6-methyladenosine methylation (m6A) dysregulation is usually associated with the pathogenesis of a range of diseases, including cancer, but the function and underlying mechanisms of m6A in regulating gastric cancer initiation and progression are still poorly understood. Here, we have found methytransferase like 3 (METTL3) and the level of RNA m6A modification were significantly upregulated in gastric cancerous tissues relative to their normal counterparts. In addition, higher METTL3 expression always predicted poorer outcomes for patients with gastric cancer. Methylated RNA sequencing revealed that METTL3 deposited m6A modification on FNTA (farnesyltransferase, subunit alpha) mRNA and accelerated its translation relying on YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) recognition. When METTL3 or FNTA expression was silenced in gastric cancer cells, the FNTA-mediated KRAS plasma membrane distribution was disrupted, resulting in downstream MEK/ERK signaling inactivation, which finally contributed to gastric cancer suppression in vitro and in vivo. In summary, our studies revealed a crosstalk between METTL3-mediated RNA methylation and FNTA-mediated protein modification which synergized to drive gastric cancer progression through orchestrating KRAS/ERK signaling activity. Implications: Targeting METTL3/FNTA pathway will provide an alternative to overcome the resistance of gastric cancer to canonical KRAS inhibitors.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144002697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kostianna Sereti, Anna E Russo, Ryan Raisner, Taylur P Ma, Karen E Gascoigne
{"title":"PAX8 Interacts with the SWI/SNF Complex at Enhancers to Drive Proliferation in Ovarian Cancer.","authors":"Kostianna Sereti, Anna E Russo, Ryan Raisner, Taylur P Ma, Karen E Gascoigne","doi":"10.1158/1541-7786.MCR-24-0710","DOIUrl":"10.1158/1541-7786.MCR-24-0710","url":null,"abstract":"<p><p>Activation of lineage-specific gene expression programs is mediated by the recruitment of lineage-specific transcription factors and their coactivators to chromatin. The lineage factor PAX8 drives essential gene expression in ovarian cancer cells and is required for tumor proliferation. However, the molecular details surrounding cofactor recruitment and specific activation of transcription by PAX8 remain unknown. Here, we identify an important functional interaction between PAX8 and the switch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex. We show that PAX8 can recruit SWI/SNF complexes to DNA, in which they function to open chromatin and facilitate the expression of PAX8 target genes. Genetic deletion of PAX8 results in loss of SWI/SNF from PAX8-bound enhancers, loss of expression of associated target genes, and reduced proliferation. These results can be phenocopied by pharmacological inhibition of SWI/SNF ATPase activity. These data indicate that PAX8 mediates the expression of an essential ovarian cancer proliferative program in part by the recruitment of the SWI/SNF complex, highlighting a novel vulnerability in PAX8-dependent ovarian cancer. Implications: PAX8 recruits SWI/SNF complexes to enhancers to mediate the expression of genes essential for ovarian cancer proliferation.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":"416-425"},"PeriodicalIF":4.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143365295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Epigenetic Dysregulation of Retrotransposons in Cancer.","authors":"Kwok Yu Liu, Danny Leung","doi":"10.1158/1541-7786.MCR-24-0744","DOIUrl":"10.1158/1541-7786.MCR-24-0744","url":null,"abstract":"<p><p>Approximately 97% of the human genome comprises noncoding sequences, with nearly half originating from transposable elements. Among these, retrotransposons represent a critical subclass that replicates via a \"copy-and-paste\" mechanism and significantly influences the regulation of host genomes. In both normal and pathologic contexts, retrotransposons contribute to a vast reservoir of regulatory elements that can modulate the expression of genes. If left unchecked, retrotransposons can substantially affect host transcriptional programs and genomic integrity. Therefore, various mechanisms, including epigenetic modifications, have been employed to mitigate their potentially deleterious effects. In diseases such as cancer, the epigenome is often significantly reprogrammed, which can lead to retrotransposon dysregulation. Drawing insights from recent studies conducted in human and murine cells, this review examines how retrotransposons expand the complexity of mammalian genomes, describes the impact of their epigenetic dysregulation on cancer development, and highlights the potential of targeting these sequences for therapeutic strategies.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":"369-378"},"PeriodicalIF":4.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RNF6 Inhibits Lung Adenocarcinoma Cell Proliferation by Promoting Cyclin D2 Degradation.","authors":"Yuening Sun, Liyang Jiang, Zubin Zhang, Rongrong Zhu, Jingpei Liang, Ziyang Liu, Yuanming He, Zhenqian Huang, Chunhua Ling, Xiumin Zhou, Xinliang Mao","doi":"10.1158/1541-7786.MCR-24-0703","DOIUrl":"10.1158/1541-7786.MCR-24-0703","url":null,"abstract":"<p><p>The E3 ubiquitin ligase RING finger protein 6 (RNF6) has been widely recognized for its role in promoting tumorigenesis in multiple cancers. However, we found that it is downregulated in lung adenocarcinoma (LUAD), and the molecular rationale for this discrepancy remains unclear. In the present study, we find that RNF6, but not its ΔRING inactive form, inhibits LUAD cell proliferation and migration and sensitizes LUAD to chemotherapy. To understand the molecular mechanism, we utilize affinity purification/tandem mass spectrometry (MS-MS) to analyze RNF6-interacting proteins and find that cyclin D2 (CCND2), a key regulator of the G1-S transition in the cell cycle. RNF6 physically binds to CCND2 and mediates its K48-linked polyubiquitination and subsequent degradation. However, ΔRING RNF6 fails to mediate CCND2 for ubiquitination and degradation. Moreover, Thr280 is critically important for CCND2 stability. When Thr280 is mutated, CCND2 becomes more stable and less ubiquitinated by RNF6. Furthermore, RNF6 arrests LUAD cell cycle at the G1 phase by inhibiting the CCND2/phospho-Rb signaling pathway, which is consistent with decreased cell proliferation. Lastly, RNF6 curtails the growth of LUAD xenografts in vivo, associated with decreased CCND2 expression. Therefore, RNF6 is a novel E3 ligase of CCND2 and suppresses LUAD cell proliferation. Implications: This study reveals a novel regulation on cell-cycle transition in LUAD and suggests the RNF6/CCND2 axis may represent an alternative therapeutic target for the treatment of LUAD.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":"426-437"},"PeriodicalIF":4.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143365296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Warren Phipps, Bhavneet Bhinder, Andrea Towlerton, Peter Mooka, James Kafeero, Matt Fitzgibbon, Olivier Elemento, Ethel Cesarman
{"title":"Exome Sequencing Reveals a Sparse Genomic Landscape in Kaposi Sarcoma.","authors":"Warren Phipps, Bhavneet Bhinder, Andrea Towlerton, Peter Mooka, James Kafeero, Matt Fitzgibbon, Olivier Elemento, Ethel Cesarman","doi":"10.1158/1541-7786.MCR-24-0373","DOIUrl":"10.1158/1541-7786.MCR-24-0373","url":null,"abstract":"<p><p>Kaposi sarcoma is a frequently aggressive malignancy caused by Kaposi sarcoma herpesvirus. People with immunodeficiencies, including human immunodeficiency virus (HIV), are at increased risk for developing Kaposi sarcoma, but our understanding of the contributions of the cellular genome to Kaposi sarcoma pathogenesis remains limited. To determine if there are cellular genetic alterations in Kaposi sarcoma that might provide biological or therapeutic insights, we performed whole-exome sequencing on 78 Kaposi sarcoma tumors and matched normal control skin from 59 adults with Kaposi sarcoma (46 with HIV-associated Kaposi sarcoma and 13 with HIV-negative Kaposi sarcoma) receiving treatment at the Uganda Cancer Institute in Kampala, Uganda. We found a very low mutational burden in all but one specimen (median = 11 mutations), which is the lowest number of mutations among all 33 tumor types in The Cancer Genome Atlas. No recurrent mutations were seen, and the most commonly affected oncogenic pathway was RTK/RAS. Mutational signatures included defective DNA mismatch repair and smoking. There was no evidence suggesting that multiple tumors from the same patient originated from the same original clone. The number of genome copy alterations per genome was higher in tumors from those without HIV infection and in tumors from participants with advanced stage disease, suggesting that lesions that take longer to develop may accumulate more alterations, although the number of alterations remains low compared with other cancers. Implications: Our findings indicate that the pathogenesis of Kaposi sarcoma differs from other malignancies and that the primary driver of carcinogenesis is Kaposi sarcoma-associated herpesvirus infection and expression of viral oncogenes, rather than clonal oncogenic transformation.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":"438-449"},"PeriodicalIF":4.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12048277/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Wang, Rahul Chaudhary, Justin Szpendyk, Lamyae El Khalki, Neelum Aziz Yousafzai, Ricky Chan, Amar Desai, Khalid Sossey-Alaoui
{"title":"Kindlin-2-Mediated Hematopoiesis Remodeling Regulates Triple-Negative Breast Cancer Immune Evasion.","authors":"Wei Wang, Rahul Chaudhary, Justin Szpendyk, Lamyae El Khalki, Neelum Aziz Yousafzai, Ricky Chan, Amar Desai, Khalid Sossey-Alaoui","doi":"10.1158/1541-7786.MCR-24-0698","DOIUrl":"10.1158/1541-7786.MCR-24-0698","url":null,"abstract":"<p><p>Triple-negative breast cancer (TNBC) presents significant clinical challenges because of its limited treatment options and aggressive behavior, often associated with poor prognosis. This study focuses on kindlin-2, an adapter protein, and its role in TNBC progression, particularly in hematopoiesis-mediated immune evasion. TNBC tumors expressing high levels of kindlin-2 induce a notable reshaping of hematopoiesis, promoting the expansion of myeloid cells in the bone marrow and spleen. This shift correlated with increased levels of neutrophils and monocytes in tumor-bearing mice over time. Conversely, genetic knockout (KO) of kindlin-2 mitigated this myeloid bias and fostered T-cell infiltration within the tumor microenvironment, indicating the pivotal role of kindlin-2 in immune modulation. Further investigations revealed that kindlin-2 deficiency led to reduced expression of PD-L1, a critical immune checkpoint inhibitor, in TNBC tumors. This molecular change sensitized kindlin-2-deficient tumors to host antitumor immune responses, resulting in enhanced tumor suppression in immunocompetent mouse models. Single-cell RNA sequencing, bulk RNA sequencing, and IHC data supported these findings by highlighting enriched immune-related pathways and increased infiltration of immune cells in kindlin-2-deficient tumors. Therapeutically, targeting PD-L1 in kindlin-2-expressing TNBC tumors effectively inhibited tumor growth, akin to the effects observed with genetic kindlin-2 KO or PD-L1 KO. Our data underscore kindlin-2 as a promising therapeutic target in combination with immune checkpoint blockade to bolster antitumor immunity and counteract resistance mechanisms typical of TNBC and other immune-evasive solid tumors. Implications: Kindlin-2 regulates tumor immune evasion through the systemic modulation of hematopoiesis and PD-L1 expression, which warrants therapeutic targeting of kindlin-2 in patients with TNBC.</p>","PeriodicalId":19095,"journal":{"name":"Molecular Cancer Research","volume":" ","pages":"450-462"},"PeriodicalIF":4.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143365293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}