Tomoko Matsushima

Prediction of paclitaxel sensitivity by CDK1 and CDK2 activity in human breast cancer cells

IntroductionPaclitaxel is used widely in the treatment of breast cancer. Not all tumors respond to this drug, however, and the characteristics that distinguish resistant tumors from sensitive tumors are not well defined. Activation of the spindle assembly checkpoint is required for paclitaxel-induced cell death. We hypothesized that cyclin-dependent kinase (CDK) 1 activity and CDK2 activity in cancer cells, which reflect the activation state of the spindle assembly checkpoint and the growth state, respectively, predict sensitivity to paclitaxel.MethodsCell viability assays and DNA and chromatin morphology analyses were performed in human breast cancer cell lines to evaluate sensitivity to paclitaxel and the cell cycle response to paclitaxel. We then examined the specific activities of CDK1 and CDK2 in these cell lines and in xenograft models of human breast cancer before and after paclitaxel treatment. Protein expression and kinase activity of CDKs and cyclins were analyzed using a newly developed assay system.ResultsIn the cell lines, biological response to paclitaxel in vitro did not accurately predict sensitivity to paclitaxel in vivo. Among the breast cancer xenograft tumors, however, tumors with significantly increased CDK1 specific activity after paclitaxel treatment were sensitive to paclitaxel in vivo, whereas tumors without such an increase were resistant to paclitaxel in vivo. Baseline CDK2 specific activity was higher in tumors that were sensitive to paclitaxel than in tumors that were resistant to paclitaxel.ConclusionsThe change in CDK1 specific activity of xenograft tumors after paclitaxel treatment and the CDK2 specific activity before paclitaxel treatment are both associated with the drug sensitivity in vivo. Analysis of cyclin-dependent kinase activity in the clinical setting could be a powerful approach for predicting paclitaxel sensitivity.

Specific activity of cyclin-dependent kinase I is a new potential predictor of tumour recurrence in stage II colon cancer

Background:There are no established biomarkers to identify tumour recurrence in stage II colon cancer. As shown previously, the enzymatic activity of the cyclin-dependent kinases 1 and 2 (CDK1 and CDK2) predicts outcome in breast cancer. Therefore, we investigated whether CDK activity identifies tumour recurrence in colon cancer.Methods:In all, 254 patients with completely resected (R0) UICC stage II colon cancer were analysed retrospectively from two independent cohorts from Munich (Germany) and Leiden (Netherlands). None of the patients received adjuvant treatment. Development of distant metastasis was observed in 27 patients (median follow-up: 86 months). Protein expression and activity of CDKs were measured on fresh-frozen tumour samples.Results:Specific activity (SA) of CDK1 (CDK1SA), but not CDK2, significantly predicted distant metastasis (concordance index=0.69, 95% confidence interval (CI): 0.55–0.79, P=0.036). Cutoff derivation by maximum log-rank statistics yielded a threshold of CDK1SA at 11 (SA units, P=0.029). Accordingly, 59% of patients were classified as high-risk (CDK1SA ⩾11). Cox proportional hazard analysis revealed CDK1SA as independent prognostic variable (hazard ratio=6.2, 95% CI: 1.44–26.9, P=0.012). Moreover, CKD1SA was significantly elevated in microsatellite-stable tumours.Conclusion:Specific activity of CDK1 is a promising biomarker for metastasis risk in stage II colon cancer.

CDK1 and CDK2 activity is a strong predictor of renal cell carcinoma recurrence

BACKGROUND In renal cell carcinoma (RCC), the prediction of metastasis via tumor prognostic markers remains a major problem. The objective of our study was to evaluate the efficacy of cyclin-dependent kinase (CDK)1 and CDK2 activity as a prognostic marker in human RCC. METHODS Surgical specimens were obtained from 125 patients with RCC without metastasis. Protein expression and kinase activity of CDKs were analyzed using a newly developed assay system named C2P (Sysmex, Kobe, Japan). We then examined the specific activities (SAs) of CDK1 and CDK2 and calculated CDK2SA-CDK1SA ratio in RCC. Also, risk score (RS) was examined. RESULTS A total of 125 cases were tested, though 34 cases were excluded because of low sample quality (25 cases) and assay failure (9 cases). In total, 91 cases were analyzed. They included 68 male and 23 female patients, ranging in age from 19 to 83 years. At a median follow-up of 36 months (1-109M), tumor with low CDK2SA-CDK1SA ratio showed significantly better 5-year recurrence-free survival than those with high CDK2SA-CDK1SA ratio (88.7% vs. 54.7%, P = 0.00141). Also, RS enabled the classification of RCCs into high-risk and low-risk groups, and patients with tumors classified as low RS showed better recurrence-free survival than patients with tumors with high RS (88.7% vs. 54.7%, P = 0.0141). CONCLUSION CDK1SA of tumors and the CDK2SA are both associated with recurrence and prognosis. IMPACT CDK-based risk demonstrated is strongly associated with clinical outcome. CDK-based risk should be an accurate system for predicting recurrence and survival for planning follow-up.

Recurrence risk score based on the specific activity of CDK1 and CDK2 predicts response to neoadjuvant paclitaxel followed by 5-fluorouracil, epirubicin and cyclophosphamide in breast cancers

BACKGROUND We established the cell cycle profiling (C2P) assay for specific activity (SA; activity/expression) of cyclin-dependent kinases (CDKs). C2P risk score (C2P-RS) based on CDK1 and CDK2 SAs was significantly associated with relapse in breast cancer (BC). This study was conducted to investigate the predictive value of C2P-RS for neoadjuvant chemotherapy (NAC). PATIENTS AND METHODS Among 124 eligible patients, 122 were treated with weekly paclitaxel followed by 5-fluorouracil, epirubicin and cyclophosphamide (P-FEC) and 2 were treated with paclitaxel monotherapy. C2P-RS was determined via C2P using frozen biopsy samples before NAC. RESULTS Negative estrogen receptor (ER), negative progesterone receptor (PR), positive human epidermal growth factor receptor 2 (HER2), high Ki-67 expression and intermediate + high C2P-RS were significantly associated with high pathological complete response (pCR) rates compared with positive ER (30% versus 9%), positive PR (25% versus 6%), negative HER2 (34% versus 11%), low Ki-67 expression (24% versus 7%) or low C2P-RS (24% versus 9%), respectively. The combination of C2P-RS and Ki-67 had a stronger impact on pCR than each parameter alone, and a multivariate analysis showed that the combination was an independent predictor of pCR (odds ratio 3.3, 95% confidence interval 1.1-9.5). CONCLUSIONS C2P-RS was significantly associated with pCR after P-FEC and may be a useful predictor for chemotherapy in BCs.

Validation study of the prognostic value of cyclin-dependent kinase (CDK)-based risk in Caucasian breast cancer patients

In a Japanese study, cyclin-dependent kinase (CDK) based risk determined by CDK 1 and 2 activities was associated with risk of distance recurrence in early breast cancer patients. The aim of our study was to validate this risk categorization in European early breast cancer patients. We retrospectively analyzed frozen breast cancer specimens of 352 Dutch patients with histologically confirmed primary invasive early breast cancer. CDK-based risk was determined in tumour tissues by calculating a risk score (RS) according to kinases activity and protein mass concentration assay without the knowledge of outcome. Determination of CDK-based risk was feasible in 184 out of 352 (52%) tumours. Median follow-up of these patients was 15 years. In patients not receiving systemic treatment, the proportions of risk categories were 44% low, 16% intermediate, and 40% high CDK-based risk. These groups remained significant after univariate and multivariate Cox-regression analysis. Factors associated with a shorter distant recurrence-free period were positive lymph nodes, mastectomy with radiotherapy, and high CDK-based risk. There was no significant correlation with overall survival (OS). CDK-based risk is a prognostic marker of distance recurrence of patients with early breast cancer. More validation would be warranted to use of CDK-based risk into clinical practice.

Novel Functional Assay for Spindle-Assembly Checkpoint by Cyclin-Dependent Kinase Activity to Predict Taxane Chemosensitivity in Breast Tumor Patient

Taxanes are among the drugs most commonly used for preoperative chemotherapy for breast cancer. Taxanes induce mitotic arrest and subsequent apoptosis. The spindle-assembly checkpoint (SAC) is known to be activated during mitosis, along with cyclin-dependent kinase-1 (CDK1), and is required for taxane-induced cell death. We hypothesized that CDK1 activity predicts response to taxane-containing chemotherapy. This study included breast cancer patients who received preoperative chemotherapy— taxane-containing treatment followed by anthracycline-based treatment—and then underwent surgery. Before starting taxane-containing chemotherapy, patients underwent fine-needle aspiration biopsy, and the biopsy samples were incubated in paclitaxel solution to measure CDK activity. Clinical were evaluated after taxane therapy, and pathological resposes were evaluated after completion of all preoperative chemotherapy. Thirty five patients were eligible for analysis of clinical response to taxane-containing therapy. Twenty-six patients had taxane-sensitive and 9 taxane-resistant tumors. Using a cut-off of CDK activity determined by the ROC analysis, patients were classified into SAC function and dysfunction groups. Univariate logistic regression analysis with clinicopathologic parameters showed that only CDK-based SAC functionality was significantly correlated with clinical response (P =0.017). No significant correlation was observed between SAC functionality and pathologic response. CDK-based SAC functionality significantly predicted clinical response (P =.0072, overall agreement = 71.4%), and this is a unique mechanism-based marker for predicting taxane chemosensitivity. Further, large prospective study is needed to determine CDK-based SAC functionality could be developed as a predictive biomarker.

Cyclin-dependent kinase-specific activity predicts the prognosis of stage I and stage II non-small cell lung cancer

BackgroundLung cancer is one of the leading causes of cancer death worldwide. Even with complete resection, the prognosis of early-stage non-small cell lung cancer is poor due to local and distant recurrence, and it remains unclear which biomarkers are clinically useful for predicting recurrence or for determining the efficacy of chemotherapy. Recently, several lines of evidence have indicated that the enzymatic activity of cyclin-dependent kinases could be a clinically relevant prognostic marker for some cancers. We investigated whether the specific activity of cyclin-dependent kinases 1 and 2 could predict recurrence or death in early non-small cell lung cancer patients.MethodsPatients with newly diagnosed, pathologically confirmed non-small cell lung cancer were entered into this blinded cohort study. The activity of cyclin-dependent kinases was determined in 171 samples by the C2P® assay, and the results were subjected to statistical analysis with recurrence or death as a clinical outcome.ResultsThe Cox proportional hazards model revealed that the activity of cyclin-dependent kinase 1, but not 2, was a predictor of recurrence, independent of sex, age, and stage. By contrast, cyclin-dependent kinase 2 activity was a predictor of death, independent of sex and stage.ConclusionThis study suggested the possible clinical use of cyclin-dependent kinase 1 as a predictor of recurrence and cyclin-dependent kinase 2 as a predictor of overall survival in early-stage non-small cell lung cancer. Thus, a combination of activity of cyclin-dependent kinases 1 and 2 is useful in decision-making regarding treatment strategies for non-small cell lung cancer after surgery.

Prognostic importance of cell-cycle activity and genotype in gastrointestinal stromal tumors.

e20501 Background: Size, mitosis and locus are important for risk stratification of gastrointestinal stromal tumors (GIST). Genotype and cell cycle are suggested related to aggressiveness and progression, and considered to have prognostic impact, although most reports have analyzed expression of proteins or mRNAs. In this study, we examined the biological and prognostic values of CDK activities in primary GIST with R0 surgery. METHODS Histologic Dx was done with HE and IH. Using lysate of frozen materials from 76 pts with GIST (n=70), leiomyoma (2), schwannoma (3) and abdominal sarcoma (1), CDK-specific activities were measured by the C2P system (activities of CDK1 & CDK2). The median age was 64 yrs and 33 (45%) pts were male. The median follow-up was 37 months. RESULTS KIT and PDGFRA mutations were found in 57 and 7 GIST pts, respectively, and deletion of codon 557-558 in 16 pts. Two pediatric GISTs and one with NF-1 had no mutation in both genes. CDK activities were measurable in 63 (86%) pts, and median activities of CDK1 and CDK2 of GIST (19 U and 81) were not different from those of other tumors (18 and 47). In GIST, 20 recurrences and 6 deaths were observed. Size (p=0.0001), location (p=0.0007), mitosis (p=0.0044), rupture (p=0.0105), deletion of 557-558 (p=0.0037), CDK2 (p=0.0005) and CDK ratio (CDK2/CDK1) (p=0.0004) were significantly related to recurrence. In Cox regression analysis, only mitosis (p=0.0189) and CDK2 (p=0.0070) were significantly related with recurrence. In univariant analysis, CDK2 was correlated with size, mitosis, Ki-67, location, deletion of 557-558 and rupture, and, in multiple regression analysis, CDK2 was significantly related with mitosis (p=0.0384), and marginally with location (p=0.0806). Size, location, mitosis, rupture, deletion mutations, and activities of CDK1 and CDK2 were significant prognostic factors for cause-specific survival. CONCLUSIONS Size, mitosis, location, deletion mutation of codon 557-558 and CDK2 activity are predictive for recurrence after R0 surgery of GIST. Genotyping and cell cycle analysis may be important in GIST risk stratification.

P2-11-08: Clinical Value of Combination Assay for Quantitative Determination of Cancer Biomarkers C2P and uPA/PAI-1 for Disease Recurrence Prediction of Early Breast Cancer Patients.

[Background] C2P is an assay measuring specific activities (SA; kinase activity compensated by its protein expression) of cyclin-dependent kinases CDK1 and CDK2 by examining a small piece of fresh-frozen tumor tissue. We reported previously that the C2P risk score given by CDK1SA and CDK2SA is a potent prognostic factor in node-negative breast cancer patients. Likewise, a uPA/PAI-1 ELISA test (FEMTELLE®, American Diagnostica Inc. Stamford, CT) quantitatively determines uPA (urokinase-type plasminogen activator) and PAI-1 (plasminogen activator inhibitor type-1) antigen levels in tumor tissue extracts, to identify patients with high or low risk of disease recurrence of node-negative breast cancer patients. These cancer biomarkers are recommended by the ASCO at the highest level of evidence (LOE-1) for therapy decision making in node-negative breast cancer patients. From the biological point of view, the above two assays can be placed into two categories: tumor cell proliferation for C2P and tumor cell invasion for uPA/PAI-1. This fact led us to examine the concept of combination of the two assays to better select breast cancer patients at risk. [Results] Fifty-nine cases of frozen primary breast cancer tissues were subjected to the C2P assay in a blinded manner. Twenty-one cases (40%) were categorized into “high risk”, 7 cases (14%) into “intermediate risk”, and 24 cases (46%) into “low risk”. Seven cases were judged as “not informative”. The uPA/PAI-1 results and clinical information (26: recurrent cases, 30: non-recurrent cases, 1: stage IV, 2: unknown) were provided by the TUM tumor bank. uPA/PAI-1 risk categories of 36 cases (61%) were classified “high” and 23 cases (39%) categorized “low”. C2P and uPA/PAI-1 showed statistically significant correlation to histological grading (Pearson correlation coefficient; 0.45 and 0.40, respectively). No significant correlation was observed between C2P and uPA/PAI-1. By Kaplan-Meier analysis for disease-free survival, in cases treated with endocrine therapy only, both C2P and uPA/PAI-1 showed a reproducible trend to the respective claimed performances as prognostic factors. In the combination analysis of the two parameters, where low/low was judged as “low” and the others as “high”, 11 cases (24%) were categorized into “low” and 34 cases (76%) into “high”. The sensitivity and negative predictive value for disease recurrence were 90% (19/20) and 91% (10/11), respectively. Strong statistical significance was observed between the risk categories by the log-rank test; p=0.0089, and also by Cox proportional hazards regression analysis; HR=9.18, p=0.032. By multivariate analysis, also including tumor size and nodal status, the CP2 uPA/PAI-1 combination evolved as a significant, statistically independent parameter (HR: 6.51, p Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-11-08.

Abstract 299: CDK1 and CDK2 activity is a strong predictor of renal cell cancer recurrence

Background: We established original methods enabling simultaneous analysis of protein expressions and kinase activities of the CDK (cyclin-dependent kinase) molecules in lysate of tumor tissue in a clinical setting (C2P technology, Ishihara et al: Biochim Biophys Acta. 1741; 226-233, 2005). The clinical utility of the technology was first evaluated in breast cancer, and combination analysis of CDK1 and CDK2 activity was shown to be a significant prognostic indicator for relapse (Kim et al: Ann Oncol. 19; 68-72, 2009). The objective of our study is to evaluate the efficacy of CDK1 and CDK2 activity as a prognostic marker in human renal cell carcinoma (RCC).Methods: Surgical specimens were obtained from 125 patients with RCC without metastasis. These patients were selected randomly for this study. Protein expression and kinase activity of CDKs and cyclins were analyzed using a newly developed assay system. The system to measure the CDK specific activity (SA) is named C2Ps (Sysmex, Kobe, Japan). We then examined the specific activities of CDK1 and CDK2 and calculated CDK2/CDK1 ratio in RCC. Also, risk score (RS) was examined as described in previous study (JGH van Nes et al: Br J Cancer. 100; 494-500, 2009). Cut off value was calculated by ROC analysis.Results: 125 cases were tested, though 34 cases were excluded of low sample quality (25 cases) and of assay failure (9 cases). 91 cases were analyzed. They included 68 male and 23 female patients, ranging in age from 19 to 83 years. At a median follow up of 36 months (1-109M), tumor with low CDK2/CDK1 ratio showed significantly better 5-year progression free survival (PFS) than those with high CDK2/CDK1 ratio (88.7% vs 54.7%, P=0.00141). Also, RS enabled the classification of RCCs into high-risk and low-risk groups, patients with tumors classified as low RS showed better PFS than patients with tumors with high RS (88.7% vs 54.7%, P=0.0141).Conclusion: CDK1 specific activity of tumors and the CDK2 specific activity are both associated with recurrence and prognosis. Analysis of cyclin-dependent kinase activity in the clinical setting could be a powerful approach for predicting cancer recurrence and prognosis in RCC after surgery and has potential for use as a routine laboratory test. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 299. doi:10.1158/1538-7445.AM2011-299