Cyclin‐dependent kinase 12 (CDK12) has emerged as an effective therapeutic target due to its ability to regulate DNA damage repair in human cancers, but little is known about the role of CDK12 in ...driving tumorigenesis. Here, we demonstrate that CDK12 promotes tumor initiation as a novel regulator of cancer stem cells (CSCs) and induces anti‐HER2 therapy resistance in human breast cancer. High CDK12 expression caused by concurrent amplification of CDK12 and HER2 in breast cancer patients is associated with disease recurrence and poor survival. CDK12 induces self‐renewal of breast CSCs and in vivo tumor‐initiating ability, and also reduces susceptibility to trastuzumab. Furthermore, CDK12 kinase activity inhibition facilitates anticancer efficacy of trastuzumab in HER2+ tumors, and mice bearing trastuzumab‐resistant HER2+ tumor show sensitivity to an inhibitor of CDK12. Mechanistically, the catalytic activity of CDK12 is required for the expression of genes involved in the activation of ErbB‐PI3K‐AKT or WNT‐signaling cascades. These results suggest that CDK12 is a major oncogenic driver and an actionable target for HER2+ breast cancer to replace or augment current anti‐HER2 therapies.
Synopsis
CDK12, a RNA polymerase II kinase, promotes breast cancer stem cell‐like properties mediated by WNT and ErbB‐PI3K signaling. Targeting CDK12 improves trastuzumab therapy in breast cancers characterised by HER2/CDK12 co‐amplification.
CDK12 amplification induces tumor initiation and progression, and mediates trastuzumab resistance.
CDK12 is required for transcriptional upregulation of genes involved in ErbB‐PI3K and WNT pathway activation.
CDK12 inhibition alone or in combination with trastuzumab therapy has anti‐tumor activity against HER2+ breast cancers.
CDK12, a RNA polymerase II kinase, promotes breast cancer stem cell‐like properties mediated by WNT and ErbB‐PI3K signaling. Targeting CDK12 improves trastuzumab therapy in breast cancers characterised by HER2/CDK12 co‐amplification.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Mismatch repair (MMR)-deficient cancers have been discovered to be highly responsive to immune therapies such as PD-1 checkpoint blockade, making their definition in patients, where they may be ...relatively rare, paramount for treatment decisions. In this study, we utilized patterns of mutagenesis known as mutational signatures, which are imprints of the mutagenic processes associated with MMR deficiency, to identify MMR-deficient breast tumors from a whole-genome sequencing dataset comprising a cohort of 640 patients. We identified 11 of 640 tumors as MMR deficient, but only 2 of 11 exhibited germline mutations in MMR genes or Lynch Syndrome. Two additional tumors had a substantially reduced proportion of mutations attributed to MMR deficiency, where the predominant mutational signatures were related to APOBEC enzymatic activity. Overall, 6 of 11 of the MMR-deficient cases in this cohort were confirmed genetically or epigenetically as having abrogation of MMR genes. However, IHC analysis of MMR-related proteins revealed all but one of 10 samples available for testing as MMR deficient. Thus, the mutational signatures more faithfully reported MMR deficiency than sequencing of MMR genes, because they represent a direct pathophysiologic readout of repair pathway abnormalities. As whole-genome sequencing continues to become more affordable, it could be used to expose individually abnormal tumors in tissue types where MMR deficiency has been rarely detected, but also rarely sought.
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Abstract
Breast cancer comprises several molecular subtypes with distinct clinical features and treatment responses, and a substantial portion of each subtype remains incurable. A comprehensive ...analysis of multi-omics data and clinical profiles is required in order to better understand the biological complexity of this cancer type and to identify new prognostic and therapeutic markers. Thus, there arises a need for useful analytical tools to assist in the investigation and clinical management of the disease. We developed Cancer Target Gene Screening (CTGS), a web application that provides rapid and user-friendly analysis of multi-omics data sets from a large number of primary breast tumors. It allows the investigation of genomic and epigenomic aberrations, evaluation of transcriptomic profiles and performance of survival analyses and of bivariate correlations between layers of omics data. Notably, the genome-wide screening function of CTGS prioritizes candidate genes of clinical and biological significance among genes with copy number alteration, DNA methylation and dysregulated expression by the integrative analysis of different types of omics data in customized subgroups of breast cancer patients. These features may help in the identification of druggable cancer driver genes in a specific subtype or the clinical condition of human breast cancer. CTGS is available at http://ctgs.biohackers.net.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
HER2-positive (HER2+) breast cancer is defined by HER2 oncogene amplification on chromosome 17q12 and accounts for 15−20% population of breast-cancer patients. Therapeutic anti-HER2 antibody such as ...trastuzumab is used as the first-line therapy for HER2-positive breast cancers. However, more than 50% of the patients respond poorly to trastuzumab, illustrating that novel therapy is warranted to overcome the resistance. We previously reported that in the majority of HER2+ breast-cancer patients, CDK12 is co-amplified on 17q12 and involved in developing tumors and trastuzumab resistance, proposing CDK12 as a potential drug target for HER2+ breast cancers. Here, we designed and synthesized novel 2,6,9-trisubstituted purines as potent CDK12 inhibitors showing strong, equipotent antiproliferative activity against trastuzumab-sensitive HER2+ SK-Br3 cells and trastuzumab-resistant HER2+ HCC1954 cells (GI50 values < 50 nM) both of which express a high level of CDK12. Two potent analogue 30d and 30e at 40, 200 nM greatly downregulated the levels of cyclinK and Pol II p-CTD (Ser2), as well as the expression of CDK12 downstream genes (IRS1 and WNT1) in a dose-dependent manner. We also observed structure-property relationship for a subset of potent analogues, and found that 30e is highly stable in liver microsomes with lack of CYP inhibition. In addition, 30d exhibited a synergy with trastuzumab in the both cells, suggesting that our inhibitors could be applied to alleviate trastuzumab-resistance of HER2+ breast cancers and escalate the efficacy of trastuzumab as well. Our study may provide insight into developing a novel therapy for HER2+ breast cancers.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Despite the therapeutic success of trastuzumab, HER2 positive (HER2+) breast cancer patients continue to face significant difficulties due to innate or acquired drug resistance. In this study we ...explored the potential role of CTTN in inducing trastuzumab resistance of HER2+ breast cancers.
Genetic changes of CTTN and survival of HER2+ breast cancer patients were analyzed in multiple breast cancer patient cohorts (METABRIC, TCGA, Kaplan-Meier (KM) plotter, and Hanyang University cohort). The effect of CTTN on cancer stem cell activity was assessed using the tumorsphere formation, ALDEFLUOR assay, and by in vivo xenograft experiments. CTTN-induced trastuzumab resistance was assessed by the sulforhodamine B (SRB) assay, colony formation assays, and in vivo xenograft model. RNA-seq analysis was used to clarify the mechanism of trastuzumab resistance conferred by CTTN.
Survival analysis indicated that CTTN overexpression is related to a poor prognosis in HER2+ breast cancers (OS,
= 0.05 in the Hanyang University cohort; OS,
= 0.0014 in KM plotter; OS,
= 0.008 and DFS,
= 0.010 in METABRIC). CTTN overexpression-induced cancer stem cell-like characteristics in experiments of tumorsphere formation, ALDEFLUOR assays, and in vivo limiting dilution assays. CTTN overexpression resulted in trastuzumab resistance in SRB, colony formation assays, and in vivo xenograft models. Mechanistically, the mRNA and protein levels of DKK-1, a Wnt antagonist, were downregulated by CTTN. Treatment of the β-catenin/TCF inhibitor reversed CTTN-induced cancer stem cell-like properties in vitro. Combination treatment with trastuzumab and β-catenin/TCF inhibitor overcame trastuzumab resistance conferred by CTTN overexpression in in vitro colony formation assays.
CTTN activates DKK-1/Wnt/β-catenin signaling to induce trastuzumab resistance. We propose that CTTN is a novel biomarker indicating a poor prognosis and a possible therapeutic target for overcoming trastuzumab resistance.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Gim (Porphyra sp.) and miyeok (Undaria pinnatifida) are the seaweeds most consumed by Koreans. We investigated the association between the intake of gim and miyeok and the risk of breast cancer in a ...case–control study. Cases were 362 women aged 30–65 years old, who were histologically confirmed to have breast cancer. Controls visiting the same hospital were matched to cases according to their age (sd 2 years) and menopausal status. Food intake was estimated by the quantitative FFQ with 121 items, including gim and miyeok. Conditional logistic regression analysis was used to obtain the OR and corresponding 95 % CI. The average intake and consumption frequency of gim in cases were lower than in controls. The daily intake of gim was inversely associated with the risk of breast cancer (5th v. 1st quintile, OR, 0·48; 95 % CI, 0·27, 0·86; P for trend, 0·026) after adjustment for potential confounders. After stratification analysis was performed according to menopausal status, premenopausal women (5th v. 1st quintile, OR, 0·44; 95 % CI, 0·24, 0·80; P for trend, 0·007) and postmenopausal women (5th v. 1st quintile, OR, 0·32; 95 % CI, 0·13, 0·80; P for trend, 0·06) showed similar inverse associations between gim intake and the risk of breast cancer after an adjustment for potential confounders except dietary factors. Miyeok consumption did not have any significant associations with breast cancer. These results suggest that high intake of gim may decrease the risk of breast cancer.
Proper functioning of the lymphatic system is required for normal immune responses, fluid balance, and lipid reabsorption. Multiple regulatory mechanisms are employed to ensure the correct formation ...and function of lymphatic vessels; however, the epigenetic modulators and mechanisms involved in this process are poorly understood. Here, we assess the regulatory role of mouse Dot1l, a histone H3 lysine (K) 79 (H3K79) methyltransferase, in lymphatic formation. Genetic ablation of Dot1l in Tie2(+) endothelial cells (ECs), but not in Lyve1(+) or Prox1(+) lymphatic endothelial cells (LECs) or Vav1(+) definitive hematopoietic stem cells, leads to catastrophic lymphatic anomalies, including skin edema, blood-lymphatic mixing, and underdeveloped lymphatic valves and vessels in multiple organs. Remarkably, targeted Dot1l loss in Tie2(+) ECs leads to fully penetrant lymphatic aplasia, whereas Dot1l overexpression in the same cells results in partially hyperplastic lymphatics in the mesentery. Genetic studies reveal that Dot1l functions in c-Kit(+) hemogenic ECs during mesenteric lymphatic formation. Mechanistically, inactivation of Dot1l causes a reduction of both H3K79me2 levels and the expression of genes important for LEC development and function. Thus, our study establishes that Dot1l-mediated epigenetic priming and transcriptional regulation in LEC progenitors safeguard the proper lymphatic development and functioning of lymphatic vessels.
Mel-18 has been implicated in several processes in tumor progression, in which the Akt pathway is involved as an important key molecular event. However, the function of Mel-18 in human cancers has ...not been fully established yet. Here, we examined the effect of Mel-18 on tumor angiogenesis in human breast cancer, and found that Mel-18 was a novel regulator of HIF-1α. Mel-18 negatively regulated the HIF-1α expression and its target gene VEGF transcription during both normoxia and hypoxia. We demonstrated that Mel-18 regulated the HIF-1α expression and activity via the PI3K/Akt pathway. Loss of Mel-18 downregulated Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression, consequently activating the PI3K/Akt/MDM2 pathway, and leading to an increase of HIF-1α protein level. Mel-18 modulated the HIF-1α transcriptional activity via regulating the cytoplasmic retention of FOXO3a, a downstream effector of Akt, and recruitment of HIF-1α/CBP complex to the VEGF promoter. Furthermore, our data shows that Mel-18 blocked tumor angiogenesis both in vitro and in vivo. Mel-18 overexpression inhibited in vitro tube formation in human umbilical endothelial cells (HUVECs). Xenografts in NOD/SCID mice derived from stably Mel-18 knocked down MCF7 human breast cancer cells showed increased tumor volume, microvessel density, and phospho-Akt and HIF-1α expression levels. In conclusion, our findings provide that Mel-18 is a novel regulator of tumor angiogenesis through regulating HIF-1α and its target VEGF expressions mediated by the PTEN/PI3K/Akt pathway, suggesting a new tumor-suppressive role of Mel-18 in human breast cancer.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Metastasis associated antigen 1 (MTA1) is a recently identified candidate metastasis‐associated gene that plays an important role in tumorigenesis and tumor aggressiveness, especially tumor ...invasiveness and metastasis. We analyzed the relationship between MTA1 expression and variable clinicopathological features and characterized its role in tumor angiogenesis in human breast cancers. Two hundred and sixty‐three breast cancer cases that successfully underwent surgery at Hanyang University Hospital (Seoul, Korea) between January 1989 and December 1997 were enrolled. MTA1 expression was observed by immunohistochemical staining and correlated with intratumoral microvessel density (MVD) and other clinicopathological parameters. MTA1 overexpression correlated significantly with higher tumor grade (grades 1 and 2 vs grade 3, P = 0.009). However, MTA1 expression did not correlate with tumor stage, status of estrogen and progesterone receptors, or axillary lymph node metastasis. Interestingly, MTA1 expression was found to correlate significantly with tumor MVD (P = 0.002). Survival analysis did not show a significant difference between MTA1 overexpression and poorer survival. In conclusion, MTA1 overexpression was found to be closely associated with higher tumor grade and increased tumor angiogenesis. These findings suggest MTA1 as a predictor of aggressive phenotype and a possible target molecule for anti‐angiogenic drugs in breast cancer treatment. (Cancer Sci 2006)
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The metabolomic approaches for mining biomarkers of women's cancers based on gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry combined with partial least ...squares-discriminant analysis are described.
To identify urinary potential biomarkers, the qualitative and quantitative analyses were introduced with 10 breast, 9 ovarian and 12 cervical cancer patients as well as 22 normal controls, which were considered with their ages and menopausal state.
For comprehensive metabolomic approaches, the non-targeted qualitative profiling was first achieved to get metabolic patterns of collected samples and the targeted quantitative analysis focused on hormonal metabolism was also conducted. Two known biomarkers, i.e., 5-hydroxymethyl-2-deoxyuridine and 8-hydroxy-2-deoxyguanosine, in breast cancer were also confirmed using the present methods. In addition, 3 potential biomarkers for ovarian cancer i.e. 1-methyladenosine, 3-methyluridine, and 4-androstene-3,17-dione, which were categorized in significantly increased level using one way of variance analysis (
p
<
0.05), were identified as quantitatively targeted metabolites with pattern analysis. The cancer markers identified in this study are highly related to metabolites which are responsible for oxidative DNA damage and DNA methylation process.
The present metabolomic approaches are not only useful for diagnostic tools and patient stratification, but may be mapped on metabolic network to reflect disease states.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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