Proposed nonlinear resonance laser technique for manipulating nanoparticles

We propose nonlinear resonant laser manipulation, a technique that drastically enhances the number of degrees of freedom when manipulating nano-objects. Considering the high laser intensity required to trap single molecules, we calculate the radiation force exerted on a molecule in a focused laser beam by solving the density matrix equations using the nonperturbative method. The results coherently elucidate certain recently reported puzzling phenomena that contradict the conventional understanding of laser trapping. Further, we demonstrate unconventional forms of laser manipulations using "stimulated recoil force" and "subwavelength laser manipulation."

P5-13-02: Prediction of Dasatinib Sensitivity of Breast Cancer Based on a Novel Tyrosine Kinase-Activity Profiling Assay

Background: Receptor tyrosine kinases and other membrane-associated tyrosine kinases are frequently overexpressed, activated, or mutated in cancer cells and cause aberrant signal transduction, which leads to cellular proliferation, angiogenesis, metastasis, and antiapoptosis. Blockage of these signals is considered an efficient strategy in cancer therapy, and to date, several tyrosine kinase inhibitors (TKIs) and antibody drugs targeting such kinases have been developed and are routinely used in clinics. However, the efficacy rates of the drugs are, unfortunately, limited. To provide optimum care for individual patients, an accurate prediction method for drug efficacy is now strongly demanded. Recent studies have shown that alteration of multiple kinases is involved in both primary and acquired drug resistance. Advantages of multi-targeted TKIs have also been reported. These findings indicate the need for a comprehensive evaluation of multiple kinases for predicting drug response. To achieve this, we developed a novel method of comprehensively profiling kinase activity.

Materials and methods: We characterized the membranous tyrosine kinases of breast cancer cell lines using a newly established profiling assay. Briefly, crude membrane fractions were prepared and directly subjected to the assay with nonspecific substrate (Poly(Glu4-Tyr)). The profile of the kinases in the crude membrane fraction was obtained by inhibiting the total activity with 13 selected kinds of adenosine triphosphate antagonists, independently. The residual activity (RA) of membranous kinases was defined as the percentage of activity with/without TKI.

Results: Nineteen breast cancer cell lines were classified as “sensitive” (n = 6) and “resistant” (n = 13) to dasatinib according to the definition in the publication (Cancer Res., 67 2226–38. 2007). The RA of tyrosine kinases targeted by different types of TKIs was determined by our assay, and we found that two RAs (src inhibitor 1 and PP1) showed statistically significant differences between the “sensitive” and “resistant” groups (p=0.017, and p=0.002, respectively, Student's t-test). The RA of the two TKIs were also significant predictors for dasatinib sensitivity in a receiver operating characteristic curve analysis (area under the curve: 0.846 for src inhibitor 1 and 0.910 for PP1). Since the major target of dasatinib are src family kinases, protein expressions of the src family of the cell lines were quantified by a Western blotting and compared between the groups. We found that the protein expression is not a statistically significant predictor of dasatinib sensitivity.

Conclusion: We have shown that a comprehensive tyrosine kinase activity profiling assay of cancer cells can predict dasatinib sensitivity. We plan to validate this assay prospectively in patients with breast cancer who receive dasatinib.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-02.

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.

Combination of rare right arterial variation with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. A case report

A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on the right side with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. Angiography showed the right vertebral artery to originate from the right common carotid artery, the right subclavian artery to arise separately from the descending aorta, and persistent trigeminal artery on the right side. The possible embryonic mechanism of this previously unreported variant combination is discussed.

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.

Development of indirect cavernous dural arteriovenous fistula after trapping for direct carotid cavernous fistula. A case report

SUMMARY

A 60-year-old man with direct carotid cavernous fistula (CCF) due to a motor vehicle accident underwent internal carotid artery trapping following high-flow external carotid to internal carotid artery bypass (EC-IC bypass). Follow-up angiography revealed ipsilateral complex indirect cavernous arteriovenous fistula. Although the traumatic indirect CCF angioarchitecture differs from cavernous-sinus dural arteriovenous fistula (CS-DAVF), the present indirect fistula was similar to the latter. Complex indirect CCF can occur after treatment of direct CCF caused by severe head injury.

Endovascular treatment of a vertebral artery aneurysm via puncture of the surgically exposed vertebral artery

We describe a case of subarachnoid hemorrhage due to a ruptured right vertebral artery (VA) aneurysm where endovascular therapy via a trans-femoral route was not feasible. Therefore we surgically exposed the VA and directly punctured it at the C4 level, followed by successful coil embolization. Direct access to the vertebral artery using an anterior surgical approach is an alternative in cases where the proximal side of the artery is occluded.

Use of CDK1 and CDK2 activity to predict renal cell cancer recurrence

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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 115 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: 115 cases were tested, though 32 cases were excluded of low sample quality (30 cases) and of assay failure (2 cases). 83 cases were analyzed. They included 63 male and 20 female patients, ranging in age from 19 to 83 years. At a median follow up of 33 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 (91.2% vs. 51.6%, p=0.0016). 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 (88.9% vs. 63.9%, p=0.0488).

Conclusions: 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.

No significant financial relationships to disclose.

Specific activity of cyclin dependent kinase 1 as a novel predictor of recurrence risk in stage II colon cancer

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Background: Altered cell cycle dynamics and check points are typical features of solid tumors, and cyclin dependent kinases (CDKs) play pivotal roles in these processes. Previously we have demonstrated that CDK-based analysis, composed of CDK1 and CDK2, is useful in the prediction of outcomes in early breast cancer patients (Ann Oncol. 19(1):68-72, 2008, Br J Cancer. 100(3):494-500, 2009). Clinically, there is a need for risk stratification in patients with stage II colon cancer who have a recurrence risk of 20 to 30%. Therefore we investigated the use of CDK-based analysis for recurrence prediction of stage II colon cancer patients.

Methods: Fresh frozen tissue samples of 254 patients with histologically confirmed adenocarcinoma of the colon, UICC stage II, who received primary tumor resection in Munich (217 cases), and Leiden (37 cases) were used. Protein expression and activity of CDK1 and CDK2 were determined by in vitro assays as previously described. Specific activity (SA) of CDKs was calculated as kinase activity in relation to its corresponding mass concentration.

Results: Development of distant metastasis was observed in 27 patients (10.6%) after a median follow up of 86 months. We found that predictive performance of CDK1SA, but not CDK2SA, for the metastasis was substantial and almost constant for long-term event prediction (average area under the curve (AUC) = 0.69). Tumor recurrence risk analysis in association with CDK1SA identified a low- (41% of population) and high- risk group (59%). Cox proportional hazard model analysis retained the CDK-based patient classification as an independent prognostic factor for distant metastases-free survival (low vs. high-risk group: Hazard ratio = 6.2, 95% CI: 1.45 to 26.9, p=0.0049). Clinical parameters such as grading, T-categories, age, and sex were excluded as confounding factors for CDK1SA-risk.

Conclusions: CDK1SA allows stratification of different risk subgroups of stage II colon cancer patients. CDK1SA-based analysis is useful for predicting patients with high risk of distant recurrence, who should be treated with chemotherapy.

No significant financial relationships to disclose.

Abstract P2-09-29: Cyclin-Dependent Kinase-Based Risk Score Predicts Both Clinical and Pathological Response to Neoadjuvant Paclitaxel Followed by FEC in Early Breast Cancers

Background: We have reported that breast tumors with a high ratio of cyclin-dependent kinase (CDK) 2 to CDK 1 are associated with high tumor cell proliferation and poor clinical outcome in Japanese. In addition, we have developed risk score based on CDK2/1 ratio (CDK-RS), and have demonstrated a high risk group showed a significantly poor prognosis in Hollanders (van Nes, et al: Br J C 2009: 100: 494). The aim of the present study is to evaluate the correlation of CDK-RS with response to neoadjuvant paclitaxel followed by fluorouracil + epirubicin + cyclophosphamide (FEC) in breast cancers.

Material and Methods: Of 131 primary breast cancer patients (age: 25-73y, mean: 51.7y), 126 were treated with paclitaxel (80 mg/m2, weekly) for 12 cycles followed by FEC (500/75/500 mg/m2, q3w) for four cycles and 5 were treated with paclitaxel-monotherapy (5 — 29 cycles) in the NAC or primary chemotherapy setting. Frozen tumor tissues were obtained from core needle biopsy before NAC, and CDK-RS was determined by the Cell Cycle Profiling (C2P) assay as previously reported. Clinical response was evaluated with MRI before NAC and after paclitaxel and FEC. Patients were classified into responders showing ≥80 % in reduction rates and non-responders showing < 80 %. Pathological CR (pCR) was defined as no residual invasive foci and no axillary lymph node metastasis. Results: Patients characteristics were as follows: menopausal status: pre-47%, post-53%; Stage: II 68%, III 27%, IV 7%; Tumor size (cm): ≥5 cm 73%, > 5 cm 27%; histologic grade (HG): I 16%, II 60%, III 24%; ER: (+) 56%, (-) 44%; PR: (+) 39%, (-) 61%; HER2: (+) 28%, (-) 72%. Of 131 patients, 22 (18%) attained pCR but 100 (82%) did not pCR (9 were excluded from evaluation of pathologic response because of stage IV diseases, no operations, and not available pathologic examination). In CDK-RS, 47% of 131 tumors were classified into high, 17% intermediate, and 37% low. In combination with high + intermediate risk score groups, that group had a tendency to show high HG (grade 2 or 3) (87% vs 78%), ER negativity (49% vs 35%), and PR negativity (65% vs 54%) compared with a low risk group, but their differences were not statistically significant. Tumors in the high + intermediate group were significantly more likely to show clinical response after the completion of not only paclitaxel (52% vs 27%, p=0.006) but also FEC (75% vs 52%, p=0.011) as well as to show pCR (24% vs 9%, p=0.037) compared with a low risk score group. In univariate analysis, CDK-RS showed a significant correlation with pCR (high + intermediate vs low, Odds ratio 4.03, 95%CI 1.03 — 10.3, p=0.045).

Discussion: CDK-RS in tumor samples before NAC is significantly associated with clinical and pathological response to paclitaxel followed by FEC. Thus CDK-RS seems to be a novel and useful predictive factor for paclitaxel — FEC in breast cancers.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-29.