A simple and low-cost chip bonding solution for high pressure, high temperature and biological applications

The sealing of microfluidic devices remains a complex and time-consuming process requiring specific equipment and protocols: a universal method is thus highly desirable. We propose here the use of a commercially available sealing tape as a robust, versatile, reversible solution, compatible with cell and molecular biology protocols, and requiring only the application of manually achievable pressures. The performance of the seal was tested with regards to the most commonly used chip materials. For most materials, the bonding resisted 5 bars at room temperature and 1 bar at 95 °C. This method should find numerous uses, ranging from fast prototyping in the laboratory to implementation in low technology environments or industrial production.

BRCAness is beneficial for indicating triple negative breast cancer patients resistant to taxane

AIM

Triple negative breast cancer (TNBC) is a heterogeneous disease and is associated with the cancer stem cell (CSC), basal-like, and BRCA1 function deficient (BRCAness) subtypes. We examined these 3 subtypes in TNBC and compared their chemosensitivity against anthracycline or taxane with a special attention to BRCAness.

METHODS

Sixty-six TNBC cases were obtained from a randomized phase II trial comparing TCx6 (TC6) with FEC-Docetaxel (FEC-D) as neoadjuvant chemotherapy. The core needle specimens before chemotherapy were used for subtyping. The basal-like and CSC subtypes were identified by immunohistochemistry; CK5/6 and EGFR staining for the basal-like subtype and ALDH1 staining for the CSC subtype. The BRCAness subtype was examined by Multiplex Ligation-dependent Probe Amplification (MLPA). Correlations between subgroups and pCR rates according to each regimen and subtype were examined.

RESULTS

The basal-like and BRCAness subtypes were significantly associated (p = 0.010) with the other subtypes, but not the CSC subtype. The pCR rates were higher with FEC-D than with TC6 in the basal-like (54.5% vs 14.3%, p = 0.081) and BRCAness (56.2% vs 16.7%, p = 0.030) subtypes. Both were not effective in the CSC subtype (18.2% vs 11.8%, p = 1.00).

CONCLUSION

BRCAness identified by MLPA was practically useful for treatment selection for avoiding taxane. ALDH1 may be considered as a marker for the CSC subtype requiring novel agents.

Abstract P2-11-04: Serum IgG response against prostate-related antigen revealed by personalized peptide vaccination in patients with metastatic recurrent breast cancer

Purpose: We have indicated that IgG and CTL boosting response could be a potential prognostic factor for overall survival (OS) and progression free survival (PFS) in metastatic recurrent breast cancer (mrBC) patients, who had received personalized selected peptide vaccine (PPV) therapy in our previously reported clinical phase II study. The aim of this study is to identify the prognostic role of serum value of IgG antibody against prostate related-antigen (PRA), including prostate-specific antigen (PSA), prostate specific membrane antigen (PSMA) and prostate acid phosphatase (PAP) in mrBC patients

Methods: Peripheral blood samples of 77 patients with mrBC were analyzed for serum anti-PRA IgG levels before and after 6th and 12th PPV therapy prospectively. Most of the peptides using for PPV are derived from cancer associated antigens expressing in various types of advanced cancers, but the peptides derived from PRAs were not used in this study.

Results: After PPV therapy, total serum levels of anti-PRA IgG were significantly increased in 31 mrBC patients (Group 1) whereas in remaining 46 rmBC patients (Group 2). Either serum anti-PSA, anti-PAP and/or anti-PMSA IgGs showed a significant increase in patients of Group 1 after 6th (p=0.045) and 12th PPV treatment (p < 0.001), irrespective of their intrinsic subtypes. The median PFS and median OS of Group 1 patients were 8.1 and 14.3 months, while those of Group 2 patients were 5.1 and 10.8 months, respectively. Anti-PRA IgG levels were significantly associated with PFS (p=0.0073; HR: 0.37) and OS (p=0.025; HR: 0.43) between these two groups, whereas no significant relation was found with age, clinical response rate and recurrent metastatic status.

Conclusions: The Group 1 patients with elevated anti-PRA IgG may have better prognosis compared to Group 2 patients who showed no IgG elevation after PPV treatment for rmBC. These results indicated a clinical significance between pre-and post- treatment measurement of serum anti-PRA IgGs in mrBC patients receiving PPV therapy, and may be a useful prognostic marker for monitoring the outcome to PPV treatment of breast cancer.

Citation Format: Toh U, Okabe M, Iwakuma N, Mishima M, Shichijo S, Yamada A, Noguchi M, Itoh K, Akagi Y. Serum IgG response against prostate-related antigen revealed by personalized peptide vaccination in patients with metastatic recurrent breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-04.

Abstract P4-09-25: Exploring immunomodulatory effects of zoledronic acid in breast cancer from clinical trial result of neoadjuvant chemotherapy with zoledronic acid: JONIE-1 study

Background: We previously reported that the addition of zoledronic acid (ZOL) to neoadjuvant chemotherapy (CT) is potentially beneficial in postmenopausal patients with triple-negative breast cancer (BC) in JONIE-1 Study (0% pCR rate in CT versus 50% in CT combing ZOL [CTZ], p=0.029). In order to find biomarkers of response to ZOL, a pilot study was performed using 30 core needle biopsy (CNB) samples at diagnosis from JONIE-1 study. We found that Src activation was highly associated with pCR compared to non-pCR especially in CTZ group. CD8+ TIL was also highly associated with pCR compared to non-pCR. None of CD8+ TIL low patients resulted in pCR in CT group but four out of ten CD8+ TIL low patients experienced pCR in CTZ group. From the result of pilot study, we consider Src activation as a promising biomarker for response to chemotherapy especially in combination with ZOL; however, Src inhibition by ZOL in vivo and the mechanism to explain tumor inhibition is unknown. Because ZOL was effective even in CD8+ TIL low group, the possibility of immune response alteration by ZOL still remains. Not all tumors with Src activation and CD8+ TIL had benefit from ZOL, emphasizing the need for additional markers of response. In the present study, we focused on Src and multiple molecules relating to cancer immune response and analyzed associations with pCR.

Patients and Methods: We investigated the relationship between clinicopathological features and tumor shrinkage in Stage IIA-IIIB HER-2-negative BC patients from the JONIE-1 adjuvant phase III trial comparing CT (FEC100 q3w × 4 cycles followed by weekly paclitaxel for 12 cycles) versus CT combining ZOL (4mg q3-4w). To access Src activation, HLA class I expression, PD-1 and PD-L1 expression, we performed immunohistochemistry (IHC) and stained slides were evaluated by pathologists. Infiltration of immature dendritic cells, macrophages, cytotoxic T cells, and regulatory T cells in the tumor were assessed by IHC as well. Formalin fixed, paraffin embedded CNB sample at diagnosis and surgical specimen after neoadjuvant CT were processed for HE staining and IHC using primary antibodies as follows; anti-Src Ab (36D10), anti-pan HLA-class I Ab (EMR8-5), anti-CD8 Ab (Clone C8/144B), anti-FOXP3 Ab (Clone 236A/E7), anti-CD68 Ab (Clone PGM1), anti-CD1a Ab (Clone O10).

Results: All IHC were successfully performed. Stained slides are now under evaluation by pathologist. Associations between clinicopathological features and the effect of CT with ZOL will be under investigation.

Discussion: Src activation was observed in more than 70% of triple negative BC. Multiple cellular functions of Src are mediated by Ras which is the main target of ZOL in osteoclasts. It has been reported that ZOL reverted tumor-infiltrating macrophages (TAM) phenotype from M2 to M1. Moreover, recent study showed that the activation Src and MAPK in melanoma cells promotes PD-L1 expression. Therefore the addition of ZOL might help cytotoxic T cells infiltrate the tumor for inhibiting tumor growth. We will present the results and discuss antitumor effects of ZOL through immunomodulation at the meeting.

Citation Format: Sangai T, Sato E, Ishikawa T, Kaise H, Hasegawa Y, Miura D, Takao S, Suzuki M, Tanino H, Horiguchi J, Akazawa K, Yamada A, Kohno N. Exploring immunomodulatory effects of zoledronic acid in breast cancer from clinical trial result of neoadjuvant chemotherapy with zoledronic acid: JONIE-1 study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-25.

A practical and efficient synthesis of methyl levulinate from cellulosic biomass catalyzed by an aluminum-based mixed acid catalyst system

A combination of aluminum compounds and organic sulfonic acids was an efficient catalyst system for direct methyl levulinate synthesis from both microcrystalline cellulose and wood powder.

Donor site selection and clinical outcomes of nipple-areola skin-sparing mastectomy with immediate autologous free flap reconstruction: A single-institution experience

BACKGROUND

The objective of this study was to examine the clinical outcomes of immediate breast reconstruction using perforator flaps from different donor sites, and to characterize the trends among these flaps.

METHODS

We retrospectively reviewed 136 consecutive patients who underwent immediate breast reconstruction using free flaps after skin-sparing mastectomy (SSM) or nipple-sparing mastectomy (NSM). The whole breast was pathologically analyzed in 5-mm sections. Breast reconstruction was performed using the deep inferior epigastric perforator (DIEP) flap, gluteal artery perforator (GAP) flap, and posterior medial thigh perforator (PMTP) flap. Patient characteristics were compared among donor sites.

RESULTS

NSM was converted to SSM because of intraoperative subareolar tumor positivity in 7 of 107 patients. Eleven patients had positive margins in permanent sections. All but one patient had a positive horizontal margin in the peripheral direction. The 5-year recurrence-free survival rate was 91.9%. The locoregional recurrence rate was 5.1% with a mean follow-up observation period of 75 months. DEIP, GAP, and PMTP flaps were used in 64 (47.1%), 38 (27.9%), and 34 (25.0%) patients, retrospectively. DIEP flaps were used in older patients and those with a higher body mass index. GAP flaps were used in younger patients. DIEP and GAP flaps were used for larger breasts, and PMTP flaps for smaller breasts.

CONCLUSION

NSM or SSM with immediate perforator flap breast reconstruction is an oncologically acceptable surgical option. We believe that age, desire to have children, body mass index, and excised breast volume are valuable factors for selecting the optimal donor site.

Estimating the probability distribution of the incubation period for rabies using data from the 1948-1954 rabies epidemic in Tokyo

Data of 98 rabies cases in dogs and cats from the 1948-1954 rabies epidemic in Tokyo were used to estimate the probability distribution of the incubation period. Lognormal, gamma and Weibull distributions were used to model the incubation period. The maximum likelihood estimates of the mean incubation period ranged from 27.30 to 28.56 days according to different distributions. The mean incubation period was shortest with the lognormal distribution (27.30 days), and longest with the Weibull distribution (28.56 days). The best distribution in terms of AIC value was the lognormal distribution with mean value of 27.30 (95% CI: 23.46-31.55) days and standard deviation of 20.20 (15.27-26.31) days. There were no significant differences between the incubation periods for dogs and cats, or between those for male and female dogs.

Relationship between paraspinal muscle cross-sectional area and relative proprioceptive weighting ratio of older persons with lumbar spondylosis

[Purpose] The purpose of this study was to examine the relationship between the paraspinal muscle cross-sectional area and the relative proprioceptive weighting ratio during local vibratory stimulation of older persons with lumbar spondylosis in an upright position. [Subjects] In all, 74 older persons hospitalized for lumbar spondylosis were included. [Methods] We measured the relative proprioceptive weighting ratio of postural sway using a Wii board while vibratory stimulations of 30, 60, or 240 Hz were applied to the subjects’ paraspinal or gastrocnemius muscles. Back strength, abdominal muscle strength, and erector spinae muscle (L1/L2, L4/L5) and lumbar multifidus (L1/L2, L4/L5) cross-sectional areas were evaluated. [Results] The erector spinae muscle (L1/L2) cross-sectional area was associated with the relative proprioceptive weighting ratio during 60Hz stimulation. [Conclusion] These findings show that the relative proprioceptive weighting ratio compared to the erector spinae muscle (L1/L2) cross-sectional area under 60Hz proprioceptive stimulation might be a good indicator of trunk proprioceptive sensitivity.

Association between tongue and lip functions and masticatory performance in young dentate adults

Motor functions of masticatory organs such as the tongue, lips, cheeks and mandible are known to deteriorate with age, thereby influencing masticatory performance. However, there are few reports on the relationships between tongue and lip functions and masticatory performance. To investigate the relationship between tongue and lip functions and comprehensive masticatory performance, by evaluating crushing, mixing and shearing abilities in young dentate adults. Participants comprised 51 dentate adults with a mean age of 25 years. Maximum tongue pressure and oral diadochokinesis were measured to evaluate tongue and lip functions. A multiple sieving method using peanuts was performed to evaluate crushing ability. A colour-changeable chewing gum was performed to evaluate mixing ability. A test gummy jelly was performed to evaluate shearing ability. The relationship between tongue and lip functions and each masticatory performance was assessed using Pearson's correlation coefficients. In addition, stepwise multiple regression analysis was performed to identify predictors of crushing ability. Crushing ability was significantly correlated with maximum tongue pressure and the number of repetitions of the syllables /pa/, /ta/ and /ka/. Maximum tongue pressure and number of repetitions of the syllable /pa/ were identified as significant predictors for crushing ability. Mixing ability was significantly correlated with the number of repetitions of the syllable /pa/. Shearing ability was not significantly correlated with tongue and lip functions. Masticatory performance during the chewing of brittle foods such as peanuts and solid foods such as chewing gum appears to be correlated with tongue and lip functions.

Enhanced in vitro biological activity generated by surface characteristics of anodically oxidized titanium--the contribution of the oxidation effect

Anodically oxidized titanium surfaces, prepared by spark discharge, have micro-submicron surface topography and nano-scale surface chemistry, such as hydrophilic functional groups or hydroxyl radicals in parallel. The complexity of the surface characteristics makes it difficult to draw a clear conclusion as to which surface characteristic, of anodically oxidized titanium, is critical in each biological event. This study examined the in vitro biological changes, induced by various surface characteristics of anodically oxidized titanium with, or without, release of hydroxyl radicals onto the surface. Anodically oxidized titanium enhanced the expression of genes associated with differentiating osteoblasts and increased the degree of matrix mineralization by these cells in vitro. The phenotypes of cells on the anodically oxidized titanium were the same with, or without, release of hydroxyl radicals. However, the nanomechanical properties of this in vitro mineralized tissue were significantly enhanced on surfaces, with release of hydroxyl radicals by oxidation effects. In addition, the mineralized tissue, produced in the presence of bone morphogenetic protein-2 on bare titanium, had significantly weaker nanomechanical properties, despite there being higher osteogenic gene expression levels. We show that enhanced osteogenic cell differentiation on modified titanium is not a sufficient indicator of enhanced in vitro mineralization. This is based on the inferior mechanical properties of mineralized tissues, without either being cultured on a titanium surface with release of hydroxyl radicals, or being supplemented with lysyl oxidase family members.

Natural history of bleeding risk in colonic diverticulosis patients: a long-term colonoscopy-based cohort study

BACKGROUND

The natural history of bleeding risk from colonic diverticulosis remains unclear.

AIM

To identify the incidence of bleeding in colonic diverticulosis patients and associated risk factors.

METHODS

A cohort of 1514 patients with colonoscopy-confirmed asymptomatic diverticulosis was selected between 2001 and 2013. Age, sex and location of colonic diverticulosis (right or left side, or bilateral) were assessed. The endpoint was a bleeding event, and data were censored at the time of last colonoscopy. The cumulative and overall incidences of bleeding were estimated using the Kaplan-Meier and person-years methods. The Cox proportional hazards model was used to estimate age- and sex-adjusted hazard ratios (aHRs).

RESULTS

The median follow-up period was 46 months. Bleeding events occurred in 35 patients, and the median time-to-event interval was 50 months. Kaplan-Meier analysis showed that the cumulative incidence of diverticular bleeding was 0.21% at 12 months, 2.2% at 60 months and 9.5% at 120 months. By the person-years method, the overall incidence rate of bleeding was 0.46 per 1000 patient-years. On multivariate analysis, age ≥70 (aHR. 3.7) and bilateral diverticulosis (aHR, 2.4) were significant risk factors for bleeding.

CONCLUSIONS

This long-term follow-up study demonstrated that the cumulative incidence of bleeding from diverticulosis was approximately 2% at 5 years and 10% at 10 years, and the overall incidence was 0.46 per 1000 patient-years. Bilateral diverticulosis increased the risk of bleeding.

Antiemetic efficacy of combined aprepitant and dexamethasone in patients at high-risk of postoperative nausea and vomiting from epidural fentanyl analgesia

BACKGROUND

Postoperative opioid analgesia increases the incidence of postoperative nausea and vomiting (PONV). We investigated whether a combination of the neurokinin-1 antagonist aprepitant and dexamethasone decreases PONV incidence compared with dexamethasone alone in high-risk patients receiving continuous epidural fentanyl.

METHODS

Sixty nonsmoking female patients scheduled for elective knee osteoarthritis surgery were randomly allocated to receive oral aprepitant 80 mg (aprepitant+dexamethasone group, N.=30) 2 h before anesthesia induction or no oral aprepitant (dexamethasone group, N.=30). All patients received intravenous dexamethasone 8 mg immediately before anesthesia induction. Anesthesia was maintained with remifentanil and sevoflurane. Continuous infusion of epidural analgesia, including fentanyl, was provided during and after surgery. We assessed complete response (no PONV and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity scale, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24 h after surgery.

RESULTS

The cumulative incidence of vomiting at 24 h was 3% in the aprepitant+dexamethasone group and 27% in the dexamethasone group (P=0.011). The incidence and frequency of vomiting in the late postoperative period was also significantly lower in the aprepitant+dexamethasone group than in the dexamethasone group. However, there were no significant group differences in the proportion of patients who experienced a complete response, the incidence and severity of nausea, and rescue antiemetic use at 24 h.

CONCLUSION

The combination of aprepitant and dexamethasone was more effective in preventing postoperative vomiting compared with dexamethasone alone in patients at high-risk of PONV from continuous epidural fentanyl analgesia.

A prospective feasibility study of sentinel node biopsy by modified Indigocarmine blue dye methods after neoadjuvant chemotherapy for breast cancer

BACKGROUND

Although sentinel lymph node biopsy (SLNB) is a standard staging method for assessing nodal status of breast cancer patients, SLNB after neoadjuvant chemotherapy (NAC) remains controversial. The aim of this study was to validate the practicality and accuracy of SLNB by our modified Indigocarmine blue dye methods following NAC.

METHODS

One hundred consecutive cases with breast cancers treated by NAC were enrolled in this study. After NAC, all patients underwent SLNB performed by our modified Indigocarmine blue dye methods without radioisotope, followed by back-up axillary lymph node dissection (ALND).

RESULTS

Sentinel nodes (SNs) were identified in 94 cases (identification rate, 94%); the accuracy was 94.7% (89/94 cases); and the false negative rate (FNR) 13.5% (5/37 cases). For cases with vs. without clinically evident metastatic nodes before NAC, the identification rate was 92.4% (61/66 cases) vs. 97.1% (33/34 cases); the accuracy 91.8% (56/61 cases) vs. 97.0% (32/33 cases) and the FNR 16.1% (5/31 cases) vs. 0% (0/6 case), respectively. There were six patients without identified SNs, three of them had metastatic nodes. False negatives occurred in five cases; in four, fewer than two sentinel nodes had been removed.

CONCLUSION

Following NAC, the accuracy of SLNB by modified Indigocarmine blue dye methods is adequate compared with other tracers. In patients in whom no SNs have been identified, lymphatic metastasis is likely and therefore ALND is recommended. For patients with cN0 prior to NAC, SLNB by modified Indigocarmine blue dye methods is clinically feasible, though controversial for patients with positive nodes.

Six-axis multi-anvil press for high-pressure, high-temperature neutron diffraction experiments

We developed a six-axis multi-anvil press, ATSUHIME, for high-pressure and high-temperature in situ time-of-flight neutron powder diffraction experiments. The press has six orthogonally oriented hydraulic rams that operate individually to compress a cubic sample assembly. Experiments indicate that the press can generate pressures up to 9.3 GPa and temperatures up to 2000 K using a 6-6-type cell assembly, with available sample volume of about 50 mm(3). Using a 6-8-type cell assembly, the available conditions expand to 16 GPa and 1273 K. Because the six-axis press has no guide blocks, there is sufficient space around the sample to use the aperture for diffraction and place an incident slit, radial collimators, and a neutron imaging camera close to the sample. Combination of the six-axis press and the collimation devices realized high-quality diffraction pattern with no contamination from the heater or the sample container surrounding the sample. This press constitutes a new tool for using neutron diffraction to study the structures of crystals and liquids under high pressures and temperatures.

Outcomes of immediate perforator flap reconstruction after skin-sparing mastectomy following neoadjuvant chemotherapy

BACKGROUND

The impact of neoadjuvant chemotherapy (NACT) on immediate free flap breast reconstruction remains controversial. Furthermore, the oncological outcomes of immediate free flap breast reconstruction after skin-sparing mastectomy (SSM) following NACT remain unclear. This study aimed to investigate the surgical complications and oncological outcomes of immediate perforator flap reconstruction after SSM following NACT.

METHODS

A total of 201 consecutive patients with indications for immediate perforator flap reconstruction after SSM were included between 2004 and 2012. Surgical and oncological outcomes were compared between patients with and without NACT.

RESULTS

There were 38 patients in the NACT group and 163 in the non-NACT control group. The median age of the NACT group was 39.5 years, which was significantly younger than the control group (43.0 years; P < 0.05). Patients in the NACT group also had more advanced and aggressive disease (P < 0.05). There was no significant difference in the frequency of surgical complications between the groups, no difference in the type of complications, and no significant difference in the frequencies of major and minor complications. No patients in the NACT group had delayed adjuvant therapy. Eight patients (4%) developed recurrences, with a median follow-up time of 3.0 years. Local recurrences occurred in three control patients but no patients in the NACT group.

CONCLUSION

NACT does not affect short-term or interim outcomes after immediate perforator flap reconstruction and may thus represent a safe and practical treatment option for the multidisciplinary treatment of breast cancer.

Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: high seafood consumers, high freshwater fish consumers and pregnant women

Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC-MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination values<LOD considered as 0), high freshwater fish consumers appear as the most exposed to PFOS (7.5 ng.kg(-1) bw.d(-1)), PFUnA (1.3 ng.kg(-1) bw.d(-1)), PFDA (0.4 ng.kg(-1) bw.d(-1)) and PFHpS (0.03 ng.kg(-1) bw.d(-1)) while high seafood consumers appear as the most exposed to PFOA (1.2 ng.kg(-1) bw.d(-1)), PFNA (0.2 ng.kg(-1) bw.d(-1)) and PFHxS (0.06 ng.kg(-1) bw.d(-1)). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals.

Kinetic Interpretation of the Importance of OATP1B3 and MRP2 in Docetaxel-Induced Hematopoietic Toxicity

Neutropenia is a lethal dose-limiting toxicity of docetaxel. Our previous report indicated that the prevalence of severe docetaxel-induced neutropenia is significantly associated with genetic polymorphisms in solute carrier organic anion transporter 1B3 (SLCO1B3) (encoding organic anion–transporting polypeptide 1B3 (OATP1B3)) and ATP-binding cassette subfamily C2 (ABCC2) (encoding multidrug-resistant–associated protein 2 (MRP2)). Therefore, we investigated their significance in docetaxel-induced neutropenia. In vitro experiments suggested their possible involvement in the hepatic uptake of docetaxel and its efflux from bone marrow cells. To further characterize a quantitative impact of OATP1B3 and MRP2 on neutropenia, we used an in silico simulation of the neutrophil count in docetaxel-treated subjects with functional changes in OATP1B3 and MRP2 in a pharmacokinetic/pharmacodynamic model. The clinically reported odds ratios for docetaxel-induced neutropenia risk were explained by the decreased function of OATP1B3 and MRP2 to 41 and 32%, respectively. These results suggest that reduced activities of OATP1B3 and MRP2 associated with systemic exposure and local accumulation in bone marrow cells, respectively, account for the docetaxel-induced neutropenia observed clinically.