Geminin expression is essential for embryonic development and the maintenance of chromosomal integrity. In spite of this protective role, geminin is also frequently overexpressed in human cancers and the molecular mechanisms underlying its role in tumor progression remain unclear. The histone deacetylase HDAC3 modulates transcription factors to activate or suppress transcription. Little is known about how HDAC3 specifies substrates for modulation among highly homologous transcription factor family members. Here, we have demonstrated that geminin selectively couples the transcription factor forkhead box O3 (FoxO3) to HDAC3, thereby specifically facilitating FoxO3 deacetylation. We determined that geminin–associated HDAC3 deacetylates FoxO3 to block its transcriptional activity, leading to downregulation of the downstream FoxO3 target Dicer, an RNase that suppresses metastasis. Breast cancer cells depleted of geminin or HDAC3 exhibited poor metastatic potential that was attributed to reduced suppression of the FoxO3-Dicer axis. Moreover, elevated levels of geminin, HDAC3, or both together with decreased FoxO3 acetylation and reduced Dicer expression were detected in aggressive human breast cancer specimens. These results underscore a prominent role for geminin in promoting breast cancer metastasis via the enzyme-substrate–coupling mechanism in HDAC3-FoxO3 complex formation.
Lei Zhang, Meizhen Cai, Zhicheng Gong, Bingchang Zhang, Yuanpei Li, Li Guan, Xiaonan Hou, Qing Li, Gang Liu, Zengfu Xue, Muh-hua Yang, Jing Ye, Y. Eugene Chin, Han You
Pancreatic ductal adenocarcinoma (PDAC) is almost uniformly fatal; however, some improvement in overall survival has been achieved with the introduction of nanocarriers that deliver irinotecan or paclitaxel. Although it is generally assumed that nanocarriers rely principally on abnormal leaky vasculature for tumor access, a transcytosis transport pathway that is regulated by neuropilin-1 (NRP-1) has recently been reported. NRP-1–mediated transport can be triggered by the cyclic tumor-penetrating peptide iRGD. In a KRAS-induced orthotopic PDAC model, coadministration of iRGD enhanced the uptake of an irinotecan-loaded silicasome carrier that comprises lipid bilayer–coated mesoporous silica nanoparticles (MSNPs); this uptake resulted in enhanced survival and markedly reduced metastasis. Further, ultrastructural imaging of the treated tumors revealed that iRGD coadministration induced a vesicular transport pathway that carried Au-labeled silicacomes from the blood vessel lumen to a perinuclear site within cancer cells. iRGD-mediated enhancement of silicasome uptake was also observed in patient-derived xenografts, commensurate with the level of NRP-1 expression on tumor blood vessels. These results demonstrate that iRGD enhances the efficacy of irinotecan-loaded silicasome–based therapy and may be a suitable adjuvant in nanoparticle-based treatments for PDAC.
Xiangsheng Liu, Paulina Lin, Ian Perrett, Joshua Lin, Yu-Pei Liao, Chong Hyun Chang, Jinhong Jiang, Nanping Wu, Timothy Donahue, Zev Wainberg, Andre E. Nel, Huan Meng
Tumors are capable of coopting hematopoietic cells to create a suitable microenvironment to support malignant growth. Here, we have demonstrated that upregulation of kinase insert domain receptor (KDR), also known as VEGFR2, in a myeloid cell sublineage is necessary for malignant progression of gliomas in transgenic murine models and is associated with high-grade tumors in patients. KDR expression increased in myeloid cells as myeloid-derived suppressor cells (MDSCs) accumulated, which was associated with the transformation and progression of low-grade fibrillary astrocytoma to high-grade anaplastic gliomas. KDR deficiency in murine BM-derived cells (BMDCs) suppressed the differentiation of myeloid lineages and reduced granulocytic/monocytic populations. The depletion of myeloid-derived KDR compromised its proangiogenic function, which inhibited the angiogenic switch necessary for malignant progression of low-grade to high-grade tumors. We also identified inhibitor of DNA binding protein 2 (ID2) as a key upstream regulator of KDR activation during myeloid differentiation. Deficiency of ID2 in BMDCs led to downregulation of KDR, suppression of proangiogenic myeloid cells, and prevention of low-grade to high-grade transition. Tumor-secreted TGF-β and granulocyte-macrophage CSF (GM-CSF) enhanced the KDR/ID2 signaling axis in BMDCs. Our results suggest that modulation of KDR/ID2 signaling may restrict tumor-associated myeloid cells and could potentially be a therapeutic strategy for preventing transformation of premalignant gliomas.
Yujie Huang, Prajwal Rajappa, Wenhuo Hu, Caitlin Hoffman, Babacar Cisse, Joon-Hyung Kim, Emilie Gorge, Rachel Yanowitch, William Cope, Emma Vartanian, Raymond Xu, Tuo Zhang, David Pisapia, Jenny Xiang, Jason Huse, Irina Matei, Hector Peinado, Jacqueline Bromberg, Eric Holland, Bi-sen Ding, Shahin Rafii, David Lyden, Jeffrey Greenfield
Gain-of-function (GOF) p53 mutations are observed frequently in most intractable human cancers and establish dependency for tumor maintenance and progression. While some of the genes induced by GOF p53 have been implicated in more rapid cell proliferation compared with p53-null cancer cells, the mechanism for dependency of tumor growth on mutant p53 is unknown. This report reveals a therapeutically targetable mechanism for GOF p53 dependency. We have shown that GOF p53 increases DNA replication origin firing, stabilizes replication forks, and promotes micronuclei formation, thus facilitating the proliferation of cells with genomic abnormalities. In contrast, absence or depletion of GOF p53 leads to decreased origin firing and a higher frequency of fork collapse in isogenic cells, explaining their poorer proliferation rate. Following genome-wide analyses utilizing ChIP-Seq and RNA-Seq, GOF p53–induced origin firing, micronuclei formation, and fork protection were traced to the ability of GOF p53 to transactivate cyclin A and CHK1. Highlighting the therapeutic potential of CHK1’s role in GOF p53 dependency, experiments in cell culture and mouse xenografts demonstrated that inhibition of CHK1 selectively blocked proliferation of cells and tumors expressing GOF p53. Our data suggest the possibility that checkpoint inhibitors could efficiently and selectively target cancers expressing GOF p53 alleles.
Shilpa Singh, Catherine A. Vaughan, Rebecca A. Frum, Steven R. Grossman, Sumitra Deb, Swati Palit Deb
Worldwide epidemics of metabolic diseases, including liver steatosis, are associated with an increased frequency of malignancies, showing the highest positive correlation for liver cancer. The heterogeneity of liver cancer represents a clinical challenge. In liver, the transcription factor PPARγ promotes metabolic adaptations of lipogenesis and aerobic glycolysis under the control of Akt2 activity, but the role of PPARγ in liver tumorigenesis is unknown. Here we have combined preclinical mouse models of liver cancer and genetic studies of a human liver biopsy atlas with the aim of identifying putative therapeutic targets in the context of liver steatosis and cancer. We have revealed a protumoral interaction of Akt2 signaling with hepatocyte nuclear factor 1α (HNF1α) and PPARγ, transcription factors that are master regulators of hepatocyte and adipocyte differentiation, respectively. Akt2 phosphorylates and inhibits HNF1α, thus relieving the suppression of hepatic PPARγ expression and promoting tumorigenesis. Finally, we observed that pharmacological inhibition of PPARγ is therapeutically effective in a preclinical murine model of steatosis-associated liver cancer. Taken together, our studies in humans and mice reveal that Akt2 controls hepatic tumorigenesis through crosstalk between HNF1α and PPARγ.
Cecilia Patitucci, Gabrielle Couchy, Alessia Bagattin, Tatiana Cañeque, Aurélien de Reyniès, Jean-Yves Scoazec, Raphaël Rodriguez, Marco Pontoglio, Jessica Zucman-Rossi, Mario Pende, Ganna Panasyuk
The eleven-nineteen leukemia (ENL) protein family, composed of ENL and AF9, is a common component of 3 transcriptional modulators: AF4–ENL–P-TEFb complex (AEP), DOT1L-AF10-ENL complex (referred to as the DOT1L complex) and polycomb-repressive complex 1 (PRC1). Each complex associates with chromatin via distinct mechanisms, conferring different transcriptional properties including activation, maintenance, and repression. The mixed-lineage leukemia (
Hiroshi Okuda, Boban Stanojevic, Akinori Kanai, Takeshi Kawamura, Satoshi Takahashi, Hirotaka Matsui, Akifumi Takaori-Kondo, Akihiko Yokoyama
Paradoxically, during early tumor development in many cancer types, TGF-β acts as a tumor suppressor, whereas in the advanced stages of these cancers, increased TGF-β expression is linked to high metastasis and poor prognosis. These findings suggest that unidentified mechanisms may function to rewire TGF-β signaling toward its prometastatic role in cancer cells. Our current study using non–small-cell lung carcinoma (NSCLC) cell lines, animal models, and clinical specimens demonstrates that suppression of SMAD2, with SMAD3 function intact, switches TGF-β–induced transcriptional responses to a prometastatic state. Importantly, we identified chaperonin containing TCP1 subunit 6A (CCT6A) as an inhibitor and direct binding protein of SMAD2 and found that CCT6A suppresses SMAD2 function in NSCLC cells and promotes metastasis. Furthermore, selective inhibition of SMAD3 or CCT6A efficiently suppresses TGF-β–mediated metastasis. Our findings provide a mechanism that directs TGF-β signaling toward its prometastatic arm and may contribute to the development of therapeutic strategies targeting TGF-β for NSCLC.
Zhe Ying, Han Tian, Yun Li, Rong Lian, Wei Li, Shanshan Wu, Hui-Zhong Zhang, Jueheng Wu, Lei Liu, Junwei Song, Hongyu Guan, Junchao Cai, Xun Zhu, Jun Li, Mengfeng Li
Many cancer-associated mutations that deregulate cellular metabolic responses to hypoxia also reprogram carbon metabolism to promote utilization of glutamine. In renal cell carcinoma (RCC), cells deficient in the von Hippel–Lindau (
Arimichi Okazaki, Paulo A. Gameiro, Danos Christodoulou, Laura Laviollette, Meike Schneider, Frances Chaves, Anat Stemmer-Rachamimov, Stephanie A. Yazinski, Richard Lee, Gregory Stephanopoulos, Lee Zou, Othon Iliopoulos
Mutations in the isocitrate dehydrogenase genes
Gary Kohanbash, Diego A. Carrera, Shruti Shrivastav, Brian J. Ahn, Naznin Jahan, Tali Mazor, Zinal S. Chheda, Kira M. Downey, Payal B. Watchmaker, Casey Beppler, Rolf Warta, Nduka A. Amankulor, Christel Herold-Mende, Joseph F. Costello, Hideho Okada
Loss of phosphatase and tensin homolog (PTEN) and activation of the PI3K/AKT signaling pathway are hallmarks of prostate cancer (PCa). However, these alterations alone are insufficient for cells to acquire metastatic traits. Here, we have shown that the histone dimethyl transferase WHSC1 critically drives indolent PTEN-null tumors to become metastatic PCa. In a PTEN-null murine PCa model, WHSC1 overexpression in prostate epithelium cooperated with
Ni Li, Wei Xue, Huairui Yuan, Baijun Dong, Yufeng Ding, Yongfeng Liu, Min Jiang, Shan Kan, Tongyu Sun, Jiale Ren, Qiang Pan, Xiang Li, Peiyuan Zhang, Guohong Hu, Yan Wang, Xiaoming Wang, Qintong Li, Jun Qin