Search

Background: Abemaciclib is a selective CDK4 and CDK6 inhibitor with demonstrated efficacy in hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. The most common adverse event across previous trials was early-onset diarrhea, affecting the patients’ quality of life and necessitating dose reductions. However, the exact mechanism for the lower rate of diarrhea in the other CDK4 and CDK6 inhibitors compared with abemaciclib is unknown. Ample evidence indicates that the gut microbiome is a tumor-extrinsic factor associated with the anti-tumor response; however, reported microbial signatures associated with adverse events by anti-cancer agent are inconsistent. To determine the underlying mechanism, we evaluated the correlation between diarrhea with abemaciclib and microbiota signatures in a metastatic breast cancer cohort. Methods: The KBCRN-A002 study is a multicenter, prospective cohort study, which aims to evaluate the association between gut microbiota signatures and abemaciclib-induced diarrhea in breast cancer patients. Patients with metastatic breast cancer who were receiving abemaciclib were eligible. The primary objective of this study is the correlation between diarrhea and the microbiota signatures and immune profile. Incidence and severity of diarrhea were evaluated by the Bristol stool scale at baseline, from day 1 to day 14, and at day 90 of treatment. Stool samples were collected at baseline and at day 90 after the start of abemaciclib treatment. The gut microbiota signature was evaluated by 16S rRNA analysis. Blood samples were collected at baseline and at days 14 and 90 after starting abemaciclib to evaluate the correlation between the gut microbiota signatures and the systemic immune profile in peripheral blood mononuclear cells (PBMCs). The immune profile was evaluated by mass cytometry, multi-plex cytokines assay, and RNA-sequencing of bulk PBMCs. We characterized the gut microbiota signatures, immune cell composition, immune cell signature, comprehensive cytokines, and severity of diarrhea in all patients. Results: We analyzed 39 patients, 77 stool samples, and 117 blood samples. In the preplanned interim analysis, among the 39 patients, 90% experienced diarrhea. Depleted gut microbiome α-diversity was positively associated with abemaciclib treatment and the severity of diarrhea. The relative abundances of 10 intestinal bacteria species increased and those of 18 intestinal bacteria decreased significantly after abemaciclib treatment, including bacteria known to be involved in diarrhea severity and anti-tumor immunity, such as Faecalibacterium (Table). The immune cell and cytokine profiles in PBMCs were also associated with the gut microbiota signatures. Conclusions: Gut microbiota signatures are associated with abemaciclib-induced diarrhea and the immune profile in metastatic breast cancer patients. These findings can help to elucidate the mechanism of diarrhea caused by abemaciclib and offer strategies for its management and prevention. Intestinal Microbiota Altered by Abemaciclib Citation Format: Kosuke Kawaguchi, Yurina Maeshima, Hiroshi Ishiguro, Kazuhiko Yamagami, Sachiko Takahara, Hirofumi Suwa, Masae Torii, Shigenori Nagai, Yasuaki Sagara, Wakako Tsuji, Hiroyasu Yamashiro, Takeshi Kotake, Shinji Fukuda, Kuniaki Saito, Yasuko Yamamoto, Masako Kataoka, Yuki Himoto, Atsushi Yonezawa, Yukiko Fukui, Yuki Nakamura, Wei Li, Sunao Tanaka, Satoshi Morita, Masakazu Toi. Alteration of gut microbiota signatures and its association with diarrhea during abemaciclib treatment: A multicenter prospective cohort study (KBCRN-A002 study) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-26-07.

Background: Stable humanized immune mice transplanted with peripheral blood mononuclear cells (PBMCs) derived from breast cancer patients are important models for assessing the tumor immune responses and the tumor immune microenvironment in breast cancer, helping to advance both pre-clinical and clinical research. The PBMCs of breast cancer patients exhibit various differences from those of healthy individuals depending on the stage of cancer progression, subtype, and type of treatment. Recent studies indicate an association of the self-renewal signatures of T cells with successful generation of a humanized mouse model; however, the optimal T cell signature for the successful generation of a humanized mouse model derived from cancer patient cells is poorly understood. Therefore, we examined the relationship between the signature of T cell subsets, focusing on the self-renewal signatures, in PBMCs derived from patients with breast cancer and the successful generation of a humanized immune mouse model. Materials and Methods: We collected PBMCs from 12 patients with breast cancer. All samples were stimulated with interleukin-2 and beads coated with CD3 and CD28 agonist antibodies to expand T cells. After washing, 1 × 10^7 cells/mouse were intraperitoneally injected into NOD/Shi-scid IL2rgamma (null) (NOG) mice. Transplants were performed on three mice per case. Successful engraftment of immune cells into NOG mice was defined by the presence of human CD45+ cells in one or more mice. Self-renewal signatures of in vitro expanded T cells before injection into NOG mice, including the markers T cell factor-1 (TCF-1), CD45RA, CCR7, CD95, and CXCR3, were determined using flow cytometry, mass cytometry and quantitative RT-PCR. Comparisons between groups of data were evaluated by t-test. Results: The success rate of engraftment of immune cells derived from breast cancer patients into NOG mice was 66.7% (8 out of 12 patients). After expansion, the magnitude of the CD8+ stem cell memory subset and the TCF-1 expression level on the CD4+ and CD8+ T cells in the engrafted group were significantly higher than those in non-engrafted group. TCF-1 and CCR7 mRNA levels in the engrafted group were upregulated compared with those in non-engrafted group. The success of engraftment was not associated with clinical characteristics such as breast cancer progression, subtype, or prior chemotherapy treatment. Conclusion: The self-renewal signatures of T cells from breast cancer patients were associated with successful engraftment of a humanized mouse model. These results suggest that prior identification of the self-renewal signatures of the T-cell population is of direct relevance to the appropriate design of a pre-clinical model for testing immunotherapies and for elucidating the characteristics of the tumor immune microenvironment. Citation Format: Yukiko Fukui, Kosuke Kawaguchi, Ryuji Murakami, Wei Li, Yuki Nakamura, Yurina Maeshima, Sunao Tanaka, Shinpei Kawaoka, Eiji Suzuki, Masakazu Toi. Self-renewal signatures of peripheral blood T cells are associated with successful engraftment to establish a humanized mouse model of breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-08-07.

Malignant rhabdoid tumor (MRT) is a highly aggressive pediatric malignancy with no effective therapy. Therefore, it is necessary to identify a target for the development of novel molecule-targeting therapeutic agents. In this study, we report the importance of the runt-related transcription factor 1 (

Several chemotherapy drugs induce the senescence of cancer cells; however, the mechanism underlying intracellular pH dysregulation in senescent cells remains unclear. Adenosine triphosphatase H+ transporting accessory protein 2 (ATP6AP2) plays a critical role in maintaining pH homeostasis in cellular compartments. We here report a new function of ATP6AP2 in senescent breast cancer cells induced by doxorubicin and abemaciclib treatment. ATP6AP2 expression was significantly downregulated in senescent cells, leading to aberrant pH levels that impaired lysosome function and caused immune response changes. The drugs caused cell cycle arrest and proliferation suppression through the upregulation of senescence-related genes. Additionally, senescent cells showed altered inflammatory and immune transcriptional profiles by reprogramming the senescence-associated secretory phenotype. These findings suggest that ATP6AP2-mediated pH regulation during therapy-induced senescence may be linked to immune changes in senescent cancer cells. These findings provide novel insights into understanding the cellular mechanisms underlying the response to anti-cancer drugs.

Over the past two decades, high sensitivity to HER2-amplified primary breast cancers has been achieved with HER2-targeted therapies. CDK4/6 inhibitors have long been identified as a potential treatment option for advanced breast cancer patients. However, acquired HER2 heterogeneity leading to resistance during the treatment has been identified as a bottleneck. This review focuses on the recent resistance mechanisms identified and potential therapeutic targets for conventional and combination endocrine therapies with CDK4/6 inhibitors by various breast cancer clinical trials and research groups in HER amplified and/or mutated breast cancer tumour. Activating HER2 alterations, JNK pathway, hyperactivated TORC1, co-mutations in HER2 and HER3, phenotypic changes of HER2, and few other advanced findings are identified as potential therapeutic targets in treating current HER2 endocrine therapy-resistant tumour. Along with the HER2-focused resistance mechanisms, we also describe how the microbiome may play a role in breast cancer therapy and its potential for new therapeutic strategies to overcome drug resistance in breast cancers.

Study Design: Retrospective cohort study. Objective: To develop a grading method for cervical paraspinal soft tissue damage after cervical spinal cord injury (CSCI) without major fracture based on the short T1 inversion recovery (STIR) mid-sagittal magnetic resonance image (MRI) for prediction of neurological improvements. Methods: This study included 34 patients with CSCI without major fracture, treated conservatively for at least 1 year and graded using the STIR-MRI Grade. This system consists of anterior grades; A0: no high-intensity area (HIA), A1: linear HIA, and A2: fusiform HIA, and posterior grades; P0: no HIA, P1: HIA not exceeding the nuchal ligament, and P2: HIA exceeding the nuchal ligament, within 24 hours postinjury. The American Spinal Injury Association impairment scale (AIS) and the Japanese Orthopedic Association (JOA) scores were examined. Results: Anterior grades were not significantly correlated with the AIS and JOA score. At both injury and final follow-up, the AIS in P2 patients was significantly more severe ( P = 0.007, P = 0.015, respectively) than that in P0 patients. At the injury, the AIS in P2 patients was significantly more severe ( P = 0.008) than that in P1 patients. Among P2 patients only, the JOA score at the injury (1.4 points) did not improve by the final follow-up (3.9 points). The final follow-up JOA score (3.9 points) in P2 patients was significantly lower than that (13.6 points) in P0 patients ( P = 0.016). Conclusions: Grade P2 led to poor neurological outcomes. The STIR-MRI Grade is a prognostic indicator for neurological improvements past-CSCI.

Study design A retrospective comparison of the surgical outcome after cervical laminoplasty for cervical spondylotic myelopathy (CSM) using a modified K-line based on lordosis in neck extension as a predictor: in K-line Back CSM (KB group), the K-line crosses the ventral edge of any of the spinous processes, whereas in K-line Front CSM (KF group), the K-line does not. Objective To investigate the neurological and radiological outcomes 5 years after surgery and the contact between the spinal cord and posterior elements after laminoplasty for CSM using the modified K-line. Summary of background data No indicators on a lateral radiograph can predict the neurological outcome after laminoplasty for CSM. Methods Patients with CSM were divided into KB (n = 20) and KF groups (n = 13). We compared the postoperative Japanese Orthopedic Association (JOA) score, recovery rate, grip-and-release (GR) and foot-tapping (FT) test results, alignment, and contact between the spinal cord and posterior elements between the two groups. Results The postoperative JOA score and its recovery rate were significantly lower in the KB group (12.4 points and 34.1%, respectively) than in the KF group (14.1 points and 59.0%, respectively) at final follow-up (P = 0.0415 and 0.0458). The GR and FT test results improved significantly in the KF group but not in the KB group. In the KB group, a larger lordotic angle in extension at 1 year postoperatively continued until final follow-up. The rate of recovery of the JOA score in patients with contacts at both C4/5 and C5/6 and any contact in the KB group (-1.5% and 31.9%, respectively) were lower (P = 0.0013 and 0.0534, respectively) than those in the KF group (58.6% and 60.7%, respectively). Conclusions The K-line Back predicts a poor neurological outcome after laminoplasty for CSM. Decompression with fusion may be recommended for these patients. Level of evidence 4.

This study aims to clarify the association between cervical spondylotic myelopathy (CSM) and cervical arteriosclerosis using ultrasonography that comprehensively includes spinal cord stenosis. Eighty-two consecutive patients aged over 60 years who underwent spine surgery were divided into those with CSM (n = 31; CSM group) and those with lumbar spinal stenosis without cervical myelopathy (n = 51; LSS group). Maximum spinal cord compression (MSCC) was evaluated for cervical stenosis severity using magnetic resonance (MR) images. The intima–media thickness (IMT) of the common carotid artery (CCA) and pulsatility index (PI) of the bilateral internal carotid artery (ICA) and vertebral artery (VA) were evaluated for cervical arteriosclerosis using pulsed-wave Doppler ultrasonography. Symptom severity was evaluated using the Japanese Orthopaedic Association (JOA) score. Spearman’s correlation coefficient was used to determine the relationship between the JOA score and MSCC or IMT and PI in each group. Stepwise multiple linear regression analyses were conducted with the JOA score as a dependent variable and age, sex, body mass index, cervical arteriosclerosis assessment, and MSCC as independent variables. Bilateral IMT and left-side ICA-PI were significantly negatively correlated with JOA scores in the CSM group (Right-CCA-IMT: R = − 0.412, Left-IMT: R = − 0.549, Left-ICA -PI: R = − 0.205, P

There are several assisted methods for the accurate placement of pedicle screw (PS), including fluoroscopy, a three-dimensional (3D) printed model, a local electrical conductivity measurement device (LECMD), and intraoperative computed tomography (CT) navigation.This study aimed to investigate the accuracy of PS placement and clinical results using different assisted methods.This study included 553 pedicle screws in 31 patients. We divided patients into the fluoroscopy (F) group (n = 79), 3D printed model and fluoroscopy (3D + F) group (n = 150), LECMD, 3D printed model, and fluoroscopy (LECMD + 3D + F) group (n = 171), and the intraoperative CT navigation (N) group (n = 153). We evaluated the operative time, intraoperative bleeding, number of fusion vertebrae, correction rate of the main curve, apical vertebral translation, grade of PS perforation (Grade 0: no perforation; Grade 1: 2 mm; Grade 2: 2‒4 mm; Grade 3: 4 mm), and accuracy of PS placement.The N group had a significantly longer operative time. There were no significant differences in the clinical results excluding the operative time. The accuracy of PS placement was 93.7%, 91.3%, 93.6%, and 93.5% in the F, 3D + F, LECMD + 3D + F, and N groups, respectively. The Grade 2 perforation rate was 2.5%, 0%, 0.6%, and 0.7% in the F, 3D + F, LECMD + 3D + F, and N groups, respectively.There were no significant differences in the accuracy of PS placement and clinical results excluding the operative time. The 3D printed model, LECMD, or intraoperative CT navigation would be useful to prevent Grade 2 perforation.

The smaller cross-sectional areas of the dural sacs in patients without C5 palsy after posterior cervical spine surgery may lead to less neurological improvement. The aim of this retrospective study was to clarify the differences in the cross-sectional area of the dural sac in the cervical spine and neurological improvement in patients with and without C5 palsy after posterior cervical spinal surgery. We retrospectively evaluated the postoperative cross-sectional areas of the dural sacs and neurological outcomes in patients with and without C5 palsy after posterior cervical spine surgery. We compared the postoperative cross-sectional areas of the dural sac at C4/5 and C5/6 on magnetic resonance images between the C5 palsy group (n = 19) and the no-C5 palsy group (n = 84) after posterior cervical spinal surgery 1 year postoperatively. Performance tests, namely, the 10-s grip-and-release test and the 10-s single-foot-tapping (FT) test, were compared between the two groups. Postoperative cross-sectional areas of the dural sac at C4/5 and C5/6 (233.3 mm2 and 226.6 mm2, respectively) in the C5 palsy group were significantly larger (P = 0.0036 and P = 0.0039, respectively) than those (195.0 mm2 and 193.8 mm2, respectively) in the no-C5 palsy group. Postoperative gain in the grip-and-release test was similar between the two groups. Postoperative gain in the FT test (4.9 times) in the C5 palsy group was significantly larger (P = 0.0060) than that (1.8 times) in the no-C5 palsy group. In the C5 palsy group 1 year after posterior cervical spine surgery, the cross-sectional areas of the dural sac were larger, and the 10-s single FT test improved noticeably.

Study design This was a prospective study. Objective This study aimed to investigate the accuracy of the gutter position after cervical double-door laminoplasty (LP) using intraoperative computed tomography (CT) navigation and the factors associated with C5 palsy. Summary of background data There were some reports in which the gutter position and the width of decompression in cervical LP were associated with C5 palsy; however, there were few reports about the accuracy of the gutter position. Materials and methods Thirty-three patients treated with cervical LP were enrolled. We marked our targeted gutter position on the lamina with a high-speed drill using intraoperative CT navigation and performed the LP procedure. The accuracy of the gutter position was evaluated with a postoperative CT scan. We measured the angle of the opened lamina (AOL), the proportion of the distance between the gutters and the distance of transverse diameter of spinal canal (PGSC) with a postoperative CT scan and spinal cord posterior shifting (SCPS) with preoperative and postoperative magnetic resonance imaging scans. We investigated the incidence of C5 palsy and analyzed AOL, PGSC, and SCPS between the C5 palsy (+) and (-) groups. Results The accuracy of all gutter positions was 78.4% (182/232). The accuracy of the gutter position at the right C4 and right C7 was lower than that at the other levels. The AOL in all cases was ~60 degrees. The PGSC was 90.1%-97.2%. The SCPS at C5 was the largest with 2.2 mm. C5 palsy occurred in 3 of 33 patients (9.1%). There were no significant differences in the AOL, PGSC, or SCPS between the 2 groups. Conclusions The accuracy of the gutter position using intraoperative CT navigation was good. The incidence of C5 palsy was higher in this study than in the previous reports.

Lumbar degenerative disease and dementia are increasing in super-aging societies and are both related to physical dysfunction and pain. However, the relationship between these diseases remains unclear. This cross-sectional study aimed to investigate the comorbidity rates of lumbar spinal canal stenosis (LSS) and mild cognitive impairment (MCI) and clarify the association between LSS presence, lumbar symptoms, and quality of life (QOL) related to low back pain and cognitive impairment in the Japanese population. We enrolled 336 participants (men 124; women 212; mean age 72.2 years) from a medical checkup program. LSS was diagnosed using a self-administered questionnaire, and lumbar symptoms were evaluated using the visual analog scale (low back pain, and pain and numbness of the lower limb). QOL related to low back pain was evaluated using the Japanese Orthopedic Association Back-Pain Evaluation Questionnaire (JOABPEQ: pain, and lumbar, and gait function). Radiological lumbar degeneration was classified using Kellgren-Lawrence grading and lateral radiographs of the lumbar spine. Cognitive function was measured using the Mini Mental State Examination (MMSE), and MCI was defined by a summary score of MMSE ≤27. Logistic and multiple linear regression analyses were performed to analyze the association between MCI, summary score of MMSE, and lumbar degenerative disease. The comorbidity rate of MCI and LSS was 2.1%, and the rate of MCI was 41% in participants with LSS. Lumbar function in JOABPEQ was associated with MCI. The presence of LSS and lumbar function in JOABPEQ were associated with MMSE. Over one-third of the people with LSS had MCI. The presence of LSS and deterioration of QOL due to low back pain were related to cognitive impairment. We recommend evaluating cognitive function for patients with LSS because the rate of MCI was high in LSS participants.

In breast cancer, both incidence and mortality have been increasing. Triple negative breast cancer (TNBC), one of breast cancer subtypes, is a heterogeneous nature that is negative for estrogen receptor (ER), progesterone receptor (PR) and human epithelial growth factor receptor type 2 (HER2). Due to the lack of expression of therapeutic targets, new therapeutic strategy and elucidation the mechanism of action in TNBC are strongly desired. Histone acetyltransferases E1A binding protein (p300) and CREB binding protein (CBP) are coactivators of a large number of essential transcription factors that contribute to cell survival and proliferation. p300/CBP (CREBBP) interacts with transcription factors and other proteins through histone acetyltransferase (HAT) and regulates several gene expression. Dysregulation of CREBBP HAT activity could contribute to various diseases, including cancer. It is reported that the high expression of p300 correlates with poor prognosis in breast cancers. However, the mechanism of CREBBP HAT activity remains unclear. We, therefore, focused on CREBBP and clarified its important mechanism in TNBC. In breast cancer cell lines, p300 expression was higher than the normal mammary epithelial cell (MCF10A) in mRNA and protein levels and positively correlated with that of CBP. To evaluate the roles of p300 and CBP in cell survival and proliferation, the loss of function studies was conducted. In TNBC cell line (MDA-MB-231), cell survival and proliferation significantly reduced in p300 knockdown cells. The reduction in cell survival and proliferation was also observed using p300 inhibitor (L002). To examine the mechanism of action for the reduction of cell survival and proliferation in p300 inhibition, cell cycle assay and apoptosis assay were performed. We found that the cell-cycle progression was arrested at the cell cycle G2/M phase and apoptosis induction in p300 knockdown cells. These results suggest that cell cycle G2/M phase arrest and the late stage of apoptosis are caused by p300 inhibition and p300 inhibition enhances the anti-tumor effect. To identify a mechanism responsible for the reduction of cell survival and proliferation in p300 inhibition, antibody array was performed. As a result of this assay and TCGA patients cohorts analysis, we identified survivin (BIRC5), a member of the inhibitor of apoptosis (IAP) family, as a functional novel biomarker of TNBC with significantly higher expression. These results suggest that suppression of BIRC5 through CREBBP inhibitor result in G2/M phase cell cycle arrest and apoptotic cell death in vitro and in vivo. In conclusion, CREBBP-BIRC5 transcriptional complex could be a novel therapeutic target for TNBC. Citation Format: Sunao Tanaka, Natsuki Wariishi, Nobuko Kawaguchi-Sakita, Souichi Adachi, Masakazu Toi, Yasuhiko Kamikubo. The importance of p300/CBP (CREBBP)-survivin (BIRC5) for cell cycle and apoptosis in triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-06-06.

Purpose Although the use of intraoperative computed tomography (CT)-based navigation systems is unlikely to cause intraoperative contamination more than the use of intraoperative fluoroscopy, the association between intraoperative CT/navigation and surgical site infections (SSIs) remains unclear. We investigated the incidence of SSIs and the association between intraoperative CT/navigation and SSIs for spinal surgeries. Methods Of the 512 patients who underwent spinal surgery between April 2016 and December 2020, 304 underwent C-arm intraoperative fluoroscopy and/or Medtronic O-arm intraoperative CT/navigation system. We investigated the incidence of SSIs in patients with four techniques; no intraoperative imaging C-arm only, O-arm only, and both O- and C-arm used. Multivariate logistic analyses were conducted using the prevalence of SSIs as the dependent variable. The independent variables were age, sex, and potential confounders including preoperative Japanese Orthopaedic Association (JOA) score, use of instrumentation, C-arm, and/or O-arm. Results The incidence of the SSIs in patients with no imaging, C-arm only, O-arm only, and both modalities used was 1.9%, 7.3%, 4.7%, and 8.3%, respectively. There was no significant difference in the incidence of SSIs between the four techniques. Multivariate logistic analyses showed a significant correlation between the prevalence of SSI and JOA scores (odds ratio, 0.878; 95% CI 0.759–0.990) and use of instrumentation (odds ratio, 6.241; 95% CI 1.113–34.985), but not use of O-arm. Conclusions The incidence of the SSIs in patients with only O-arm used was 4.7%. Preoperative clinical status and use of instrumentation, but not use of the O-arm, were associated with SSIs after spinal surgeries.

Study design A multicenter, retrospective study. Objective To clarify the clinical and radiological effects of removing interspinous contextures in lumbar decompression surgery for patients with lumbar spinal stenosis. Summary of background data There have seldom been reports that have compared both clinical results and radiological changes among minimally invasive decompression methods. Methods Consecutive 52 patients underwent lumbar spinous process-splitting laminectomy (LSPSL), following which 50 patients underwent trans-interspinous lumbar decompression (TISLD). All patients presented with cauda equina type of lumbar spinal stenosis and underwent a minimum 1-year follow-up. The Japanese Orthopaedic Association (JOA) score and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score were evaluated to determine the extent of daily living activities. Propensity score (PS)-matched analysis was used to match patients' age and preoperative JOA scores between the two groups. Lumbar lordosis (LL), disc height (DH), segmental range of motion (ROM), and vertebral anterior translation were measured by functional lumbar lateral X-ray, and changes between preoperative and 1-year postoperative values were evaluated. Results Twenty-nine pairs of patients were selected by PS-matching. Mean JOA scores increased from 14.4 to 23.5 (mean recovery rate was 62.3%) in the LSPSL group and from 14.0 to 23.2 (61.3%) in the TISLD group at preoperative and 1-year follow-up, respectively. There were no significant differences in clinical results and changes in LL, ROM, and vertebral anterior translation in each group. The DH at L4/5 level at 1-year after surgery revealed significant decrease in the TISLD group compared to the LSPSL group. There was a correlation between preoperative DH and DH decrease in the LSPSL group, but not in TISLD group. Conclusions Removal of interspinous contextures did not influence clinical outcomes at 1 year after surgery, but it may be likely to cause disc height loss when it applied at the L4/5 level.Level of Evidence: 3.

BackgroundThis cross-sectional study sought to determine the neck-shoulder stiffness/low back pain (NSS/LBP) comorbidity rate in a Japanese community population and to compare the quality of life (QOL) in individuals with comorbid NSS/LBP, asymptomatic individuals, and those with symptoms of NSS or LBP alone.MethodsThe sample included 1122 subjects (426 men; 696 women) with NSS and LBP symptoms in the previous 3 months, and were grouped according to NSS, LBP, comorbid NSS and LBP symptoms (Comorbid), or no symptoms (NP). They completed the MOS 36-Item Short-Form Health Survey (SF-36). Health QOL was evaluated by the eight domain scores and the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores after adjusting for age. The primary outcome was to examine the association between NSS/LBP, NSS, or LBP and bodily pain of the eight domains of SF-36. Secondary outcome was to compare health-related QOL among the four groups.ResultsMorbidity was 45.6% for NSS and 51.9% for LBP. Comorbidity affected 23% of men and 33% of women. Comorbid NSS/LBP, NSS, and LBP alone were independently associated with bodily pain after adjusting for potential confounders. Men who exhibited comorbidity had significantly lower MCS scores than asymptomatic men. Women who exhibited comorbidity and LBP had significantly lower MCS scores than those with no symptoms or NSS alone. Women who exhibited comorbidity had significantly lower MCS scores than those with no symptoms or LBP alone.ConclusionsComorbidity of the two diseases is prevalent in 23% of the men and 33% of women in the Japanese sample. Although NSS, LBP, and comorbidity were independently associated with QOL in terms of pain, QOL was worse in individuals who exhibited comorbidity than in those without symptoms or with NSS alone.

Background This study aimed to assess orthopedic surgeons’ attitudes and behaviors toward occupational radiation exposure and investigate the prevalence of occupational radiation-induced skin injury among orthopedic surgeons. Similarly, risk factors for the presence of radiation-induced skin injury were investigated. Methods Overall, 108 orthopedic surgeons were administered self-reported questionnaires about occupational radiation exposure, and their hands were then photographed. Their fields of expertise were classified into spine, arthroplasty, sports medicine, hand, oncology, rheumatoid arthritis, pediatric orthopedic, and resident. Dermatologists evaluated the surgeons’ skin conditions and classified into 3 grades of injury: grade 0, no clinical symptoms; grade 1, careful observation required; and grade 2, detailed examination required. Logistic regression analysis was performed to investigate the factors related to the presence of radiation-induced skin injury. Crude and adjusted logistic regression analysis using the backward stepwise selection method was similarly conducted. Receiver operating characteristic curve (ROC) analysis was performed to estimate the predictive power of exposure time, occupational period, and accumulated annual exposure time for radiation-induced skin injury. Results In total, 93.5% of the surgeons were careful about occupational radiation exposure, of which 76.8% used a dosimeter. Skin changes in the hands were self-reported by 42.5% of the surgeons, and radiation-induced skin injury was diagnosed in 31.4%. The accuracy of the self-reported skin changes was 100% for grade 2 and 61.5% for grade 1. Adjusted regression analysis showed that dermatologists’ diagnosis-related factors were self-reported skin changes (odds ratio [OR] 3.1) and spine surgeons (OR 3.2). ROC analysis demonstrated that an occupational period >21 years and an accumulated exposure time >6696 min were considered risk factors, with ORs of 4.07 and 5.99, respectively. Conclusions Orthopedic surgeons, particularly spine surgeons, should be regularly examined by dermatologists early in their careers for early detection of radiation-induced skin injury on the hands.

Background: Lumbar degenerative disease (LDD) and dementia are increasing in super-aging societies and are both related to physical dysfunction and pain. However, the relationship between these diseases remains unclear. This cross-sectional study aimed to investigate the rate of comorbidity of lumbar spinal stenosis (LSS) and mild cognitive impairment (MCI) by age and sex and clarify the association between LSS presence, LDD symptoms, quality of life (QOL) related to low back pain, and cognitive impairment in a Japanese population.Methods: We enrolled 1097 participants (men 437; women 660; mean age 54.6 years) from a medical checkup program. LSS was diagnosed using a self-administered questionnaire, and LDD symptoms were evaluated using visual analog scale (VAS: low back pain, pain, numbness of the lower limb). QOL related to low back pain was evaluated using the Japanese Orthopedic Association Back-Pain Evaluation Questionnaire (JOABPEQ: pain, lumbar function, and gait function), and Kellgren-Lawrence grading was performed to evaluate lumbar degeneration using lateral radiographs of the lumbar spine. Cognitive function was measured using the Mini Mental State Examination (MMSE), and we defined MCI as a summary score of MMSE £27. Logistic and multiple liner regression analyses were performed to analyze the association between MCI, summary score of MMSE and LSS factors.Results: The comorbidity rate of MCI and LSS was 0.9% in men and 0.7% in women. It was 2.1% in those aged ³65 years in both sexes, and this rate increased with age. Lumbar function in JOABPEQ (OR 0.979, 95% CI 0.961 to 0.998) and lower limb pain in VAS (OR 1.020, 95% CI 1.002 to 1.039) were associated with MCI in men. The presence of LSS, lumbar function, and gait function in JOABPEQ were associated with MMSE in both sexes, while lower limb numbness and pain in VAS were associated with MMSE in men.Conclusion: The comorbidity rate of LSS and MCI increased with age. The presence of LSS, certain symptoms of LDD, and deterioration of QOL due to low back pain were related to cognitive dysfunction. Treatment of LDD could help to improve both LDS symptoms and cognitive dysfunction.

To prospectively examine whether laminoplasty with maximal expansion induces C5 palsy, even with prophylactic bilateral C4/5 foraminotomy. Thirty-five consecutive patients with cervical myelopathy underwent laminoplasty (n = 19: LP group) or posterior decompression and fusion (n = 16: PDF group) with maximal expansion. Prophylactic bilateral C4/5 foraminotomy was performed alternately in consecutive five patients undergoing each type of surgery. In each type of surgery, the first and third consecutive five patients did not undergo foraminotomy (NF subgroup: 20 patients), while the second and fourth consecutive five patients underwent foraminotomy (F subgroup: 15 patients). The widths between the gutters was equivalent to the diameter of the spinal canal, and an inclination angle of the lamina of approximately 90° was created during laminoplasty. The incidence and severity of postoperative C5 palsy were investigated. Patients with a manual muscle testing score for the deltoid muscle and/or biceps brachii muscle of ≤ 2 were diagnosed with severe palsy. The respective incidences of C5 palsy in the F and NF subgroups were 33% and 20% in the LP group and 50% and 20% in the PDF group. Severe palsy occurred in 67% and 0% of patients who had developed palsy in F and NF subgroups, respectively, in the LP group, and in 100% of patients in the PDF group. Furthermore, 40% of the patients with severe palsy took more than 6 months to recover. Laminoplasty with maximal expansion induced C5 palsy in both the LP and PDF groups, even with the addition of prophylactic bilateral C4/5 foraminotomy.

Background Associations between whiplash injuries and quality of life (QOL) have been previously published by conducting surveys among patients. This study aimed to investigate the prevalence of whiplash injuries in a Japanese community, and the association between whiplash injuries and QOL was also determined. Methods In all, 1140 volunteers participated in this study, filled out a questionnaire about whether they had experienced a whiplash injury, or had any neck pain or neck-shoulder stiffness in the previous 3 months, and completed the Medical Outcomes Study 36-Item Short-Form Health Survey. QOL was evaluated from the eight domain scores, and the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores. We compared the characteristics, habits, history, medication, body mass index, and health-related QOL (eight domains, PCS and MCS scores) between the groups with whiplash injuries and no whiplash injuries for each sex. Multiple linear regressions with the forced-entry procedure were performed to evaluate the effects of a whiplash injury on the PCS and MCS. A p-value of Results The prevalence of whiplash injuries was 7.7% and 9.6% in men and women, respectively. The percentage of those who experienced whiplash injuries with symptoms persisting for more than 3 months was 34.3% and 24.2% in men and women, respectively. The prevalence of neck symptoms was significantly higher in the whiplash injury group than in the non-whiplash injury group. Multiple linear regression analysis showed that, although whiplash injuries were associated with poor health-related QOL in men, age was more associated with health-related QOL than whiplash injuries in both sexes. Conclusion The prevalence of whiplash injuries was 7.7% and 9.6% in men and women in local residents in Japan, respectively. Whiplash injuries were poorly associated with a poor health-related QOL in men (P = 0.015).

To compare surgical outcomes after tympanoplasty without ossiculoplasty for chronic otitis media between transcanal endoscopic ear surgery (TEES) and postauricular microscopic ear surgery (PAMES).Case-control study.Tertiary care university hospital.Consecutive patients (The surgical success rate for hearing (air-bone gap ≤20 dB) was 95.7% in the TEES group and 84.0% in the PAMES group. Lower middle ear risk resulted in similar mean (95% CI) closure of air-bone gaps (TEES: 9.6, 6.5-12.6; PAMES: 8.0, 6.4-9.7;Under favorable conditions of the middle ear, TEES and PAMES resulted in similar hearing improvement by tympanoplasty without ossiculoplasty. However, under adverse conditions of the middle ear, TEES was a more beneficial approach for hearing improvement than PAMES.

Background: HER3 signal pathways in cancer cells are thought to be involved in up-regulation of PD-L1 expression, resulting in “cold” tumor immune microenvironment (TIME). However, little is known on the association of HER3 expression and immune related molecular network in breast cancer and the functional role of HER3 signals in antitumor immune responses. Methods: The dataset of the TCGA study was analyzed to determine the correlation of HER3 expression and antitumor immune molecules. Two breast cancer patient-derived xenograft (PDX) models were treated with patritumab (anti-HER3 antibody), polyclonal activated autologous T cells (PATCs) or a combination of patritumab and PATCs (P-PATCs) in order to test immunological modulation by the regulation of HER3 signals. RT-PCR, immunohistochemical staining and CyTOF were performed in tumors or liver tissue for CD3, CD4, CD8a, CD137, CD134/OX40, CD80, IFN-γ and PD-L1, LAG3, TIM3, FOXP3. In addition, HER3-knockdown human breast cancer cell lines and PBMC were co-cultured and comprehensive cytokine expression in supernatant was analyzed by bioplex. Results: In TCGA dataset analysis, HER3 expression was inversely corelated with expression of CD4, CD8A, IFN-γ, granzyme A/B. In humanized PDX models, although treatment of PATCs or patritumab alone showed limited anti-tumor effects, P-PATCs treatment showed a significantly greater anti-tumor response. Interestingly, the proportion of CD137 expressing T cell infiltration and mRNA expression of CD137 was significantly higher in P-PATCs group compared to patritumab or the PATCs group, while the proportion of CD4/8 T cell infiltration was also higher in the P-PATCs group. CyTOF revealed that the proportion of CD137 and CD134/OX40 expressing cells was higher in P-PATCs group compared to the PATCs group. In co-culture of PBMC with HER3 knockdown cancer cells, the secretion level of immune stimulatory factors (IL2, IFN-g, TNF-a) increased and immune inhibitors (IL6, IL10) decreases. Conclusions: These data suggest that HER3 expression in breast cancer associated with “cold” TIME and the regulation of its signal converts “cold” TIME to “hot”. Thus, inhibition of HER3 signal might be of interesting concept for both regulation of oncologic signal and immunological modulation in HER3-expressing breast cancer. Further HER3 related immune modulation exploration in breast cancer treatment strategy needs to be clarified in the future. Citation Format: Sunao Tanaka, Eiji Suzuki, Takeshi Kotake, Shinpei Kawaoka, Kosuke Kawaguchi, Tomomi Nishimura, Fengling Pu, Masakazu Toi. HER3 expression is associated with cold tumor immune microenvironment and the regulation of its signal in humanized breast cancer patient derived xenograft models converts to hot tumor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6161.

VEGF stimulates endothelial cells as a key molecule in angiogenesis. VEGF also works as a multifunction molecule, which targets a variety of cell members in the tumor microenvironment. We aimed to reveal VEGF-related molecular mechanisms on breast cancer cells. VEGF-knocked-out MDA-MB-231 cells (231 VEGFKOex3 ) showed rounded morphology and shorter perimeter (1.6-fold, p < 0.0001). The 231 VEGFKOex3 cells also showed impaired cell migration (2.6-fold, p = 0.002). Bevacizumab treatment did not induce any change in morphology and mobility. Soluble neuropilin-1 overexpressing MDA-MB-231 cells (231 sNRP1 ) exhibited rounded morphology and shorter perimeter (1.3-fold, p < 0.0001). The 231 sNRP1 cells also showed impaired cell migration (1.7-fold, p = 0.003). These changes were similar to that of 231 VEGFKOex3 cells. As MDA-MB-231 cells express almost no VEGFR, these results indicate that the interaction between NRP1 and long isoform of VEGF containing a NRP-binding domain regulates the morphology and migration ability of MDA-MB-231 cells. Genome-wide gene expression profiling identified ARHGAP17 as one of the target genes in the downstream of the VEGF/NRP1 signal. We also show that VEGF/NRP1 signal controls filopodia formation of the cells by modulating Cdc42 activity via ARHGAP17. Among 1,980 breast cancer cases from a public database, the ratio of VEGF and SEMA3A in primary tumors (n = 450) of hormone-receptor-negative breast cancer is associated with ARHGAP17 expression inversely, and with disease free survival. Altogether, the bevacizumab-independent VEGF/NRP1/ARHGAP17/Cdc42 regulatory network plays important roles in malignant behavior of breast cancer.

Neoadjuvant endocrine therapy has been reported to decrease tumor size, which leads to increased breast conservation rates. To improve the clinical response, metronomic chemotherapy with endocrine therapy is a promising strategy. A multicenter phase II single‐arm neoadjuvant trial with letrozole and cyclophosphamide was conducted. Eligibility criteria included postmenopausal status, T2–4 N0–1, and estrogen receptor‐positive breast carcinoma. Letrozole (2.5 mg) plus cyclophosphamide (50 mg) was given orally once a day for 24 weeks. The primary endpoint was the clinical response rate (CRR). To investigate anti‐angiogenic effects, circulating endothelial cells (CECs) were quantified using the CellSearch system. From October 2007 to March 2010, 41 patients were enrolled. The CRR was 67.5% (52.0–80.0%), which was above the prespecified threshold (65%). The conversion rate from total mastectomy to breast‐conserving surgery was 64% (18/28). Grade 3 or greater nonhematological toxicity was not reported. Clinical response was associated with improved disease‐free survival (DFS) (P = 0.020). The increase in CEC counts at 8 weeks was observed in nonresponders (P = 0.004) but not in responders. Patients with higher CEC counts at baseline or post‐treatment showed worse DFS than those with lower counts (P

Sal-like 4 (SALL4) is a transcription factor that enhances proliferation and migration in breast cancer cells. SALL4 expression therefore has the potential to promote cancer malignancy. However, the regulatory mechanisms involved in SALL4 protein expression have not been thoroughly elucidated. In this study, we observed that treating MCF-7 and SUM159 breast cancer cell lines with a proteasome inhibitor increases SALL4 protein levels, suggesting that SALL4 is degraded by the ubiquitin–proteasome system. Using immunoprecipitation to uncover SALL4-binding proteins, we identified an E3 ubiquitin-protein ligase, tripartite motif–containing 21 (TRIM21). Using an EGFP reporter probe of the major SALL4 isoform SALL4B, we observed that shRNA-mediated knockdown of TRIM21 increases cellular SALL4B levels. Immunostaining experiments revealed that TRIM21 localizes to the nucleus, and a K64R substitution in the nuclear localization motif in SALL4B increased SALL4B levels in the cytoplasm. These results suggested that TRIM21 is involved in nuclear SALL4 degradation. To identify the amino acid residue that is targeted by TRIM21, we fragmented the SALL4B sequence, fused it to EGFP, and identified Lys-190 in SALL4B as TRIM21's target residue. Amino acid sequence alignments of SALL family members indicated that the region around SALL4 Lys-190 is conserved in both SALL1 and SALL3. Because SALL1 and SALL4 have similar functions, we constructed a SALL1-EGFP probe and found that the TRIM21 knockdown increases SALL1 levels, indicating that TRIM21 degrades both SALL1 and SALL4. Our findings extend our understanding of SALL4 and SALL1 regulation and may contribute to the development of SALL4-targeting therapies.

S‐1 and irinotecan combination is attractive for breast cancer refractory to anthracyclines and taxanes. Patients with advanced human epidermal growth factor receptor 2 (HER2)‐negative breast cancer previously treated with anthracyclines and taxanes were eligible. Patients with brain metastases and homozygous for UGT1A1 *6 or *28 or compound heterozygous (*6/*28) were excluded. A dose‐escalation design was chosen for the phase I portion (level 1: irinotecan 80 mg/m2 days 1–8 and S‐1 80 mg/m2 days 1–14 every 3 weeks; level 2: irinotecan 100 mg/m2 and S‐1 80 mg/m2). Study objectives included determination of the recommended dose for phase II, response rate, progression‐free survival (PFS), and safety. Pharmacokinetics and CD34+ circulating endothelial cells (CECs) as pharmacodynamics were also analyzed. Thirty‐seven patients were included. One patient at each level developed dose‐limiting toxicities; therefore, level 2 was the recommended dose for phase II. Diarrhea was more common in patients possessing a *6 or *28 allele compared with wild‐type homozygous patients (46% and 25%). Among 29 patients treated at level 2, PFS was longer for UGT1A1 wt/*6 and wt/*28 patients than for wt/wt patients (12 vs. 8 months, P = 0.06). PFS was significantly longer in patients with a larger‐than‐median SN‐38 area under the curve (AUC) than in those with a smaller AUC (P = 0.039). There was an association between clinical benefit and reduction in baseline CD34+ CECs by S‐1 (P = 0.047). The combination of irinotecan and S‐1 is effective and warrants further investigation.

Introduction: Lumbar spinal canal stenosis (LSS) is a very common disease. When the responsible level is considered to be L4/5 despite the appearance of double-level (L3/4 and L4/5) stenosis on magnetic resonance imaging (MRI), it is difficult for spinal surgeons to decide whether prophylactic decompression should be performed at the L3/4 level. The purpose of this study was to investigate the relationship between the dural sac cross-sectional area (DCSA) at the L3/4 level and clinical symptoms in patients with double-level stenosis. Methods: Thirty-five patients with double-level stenosis were registered in this study. All patients underwent decompression surgery at the L4/5 responsible level. The severity of patients' symptoms was evaluated by the Japanese Orthopaedic Association (JOA) score and its rate of recovery. A measurement program on MRI was used to determine the DCSA. Results: The clinical course of LSS according to the JOA score recovery rate at the final follow-up revealed that the good group (50%) included 27 patients, and the poor group (

Runt-related transcription factor 1 (RUNX1) is generally considered to function as a tumor suppressor in the development of leukemia, but a growing body of evidence suggests that it has pro-oncogenic properties in acute myeloid leukemia (AML). Here we have demonstrated that the antileukemic effect mediated by RUNX1 depletion is highly dependent on a functional p53-mediated cell death pathway. Increased expression of other RUNX family members, including RUNX2 and RUNX3, compensated for the antitumor effect elicited by RUNX1 silencing, and simultaneous attenuation of all RUNX family members as a cluster led to a much stronger antitumor effect relative to suppression of individual RUNX members. Switching off the RUNX cluster using alkylating agent–conjugated pyrrole-imidazole (PI) polyamides, which were designed to specifically bind to consensus RUNX-binding sequences, was highly effective against AML cells and against several poor-prognosis solid tumors in a xenograft mouse model of AML without notable adverse events. Taken together, these results identify a crucial role for the RUNX cluster in the maintenance and progression of cancer cells and suggest that modulation of the RUNX cluster using the PI polyamide gene-switch technology is a potential strategy to control malignancies.

Study design A retrospective study. Objective To compare long-term clinical and radiologic outcomes between conventional double-door laminoplasty (LP) (group A) and cervical LP with C3 laminectomy (group B). Summary of background data Cervical LP with C3 laminectomy preserving the semispinalis cervicis inserted into the axis decreased the patients' postoperative axial pain and muscle atrophy, prevented interlaminar bony fusion, decreased limitations of daily living activity, including reduced postoperative neck mobility, and maintained the cervical range of motion (ROM) more effectively than conventional cervical LP reattaching the semispinalis cervicis in the short-term. Materials and methods Group A included 14 patients with an average age of 56.6 years at the time of surgery (follow-up rate 58.1%), and group B included 21 patients with an average age of 56.3 years at the time of surgery (follow-up rate 29.1%). We evaluated the clinical results, which included the Japanese Orthopaedic Association (JOA) score, JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and radiologic results, including C2-C7 ROM, number of interlaminar bony fusions and presence of new spondylolisthesis at C3. Results There were no significant differences in preoperative and postoperative JOA scores, recovery rate of JOA score, and JOACMEQ. Significantly fewer patients in group B experienced interlaminar bony fusion at C2-C3 compared with those in group A. There was no significant difference in the presence of new spondylolisthesis at C3. In patients with cervical spondylotic myelopathy, the rate of decrease of C2-C7 ROM was significantly less in group B than in group A. In patients with ossification of the posterior longitudinal ligament, there was no significant difference in the rate of decrease of C2-C7 ROM between the groups. Conclusions C3 laminectomy prevented interlaminar bony fusion at C2-C3. C3 laminectomy maintained cervical ROM in patients with cervical spondylotic myelopathy. There were no adverse events due to C3 laminectomy at 10 years postsurgery.

Anticancer agents are used for cancer therapy. Studies on the biological response to treatment with an agent facilitate its effective use. Eribulin mesylate (eribulin) is an anticancer agent. In this study, we found that c-Fos is upregulated in response to eribulin treatment in the triple-negative breast cancer cell lines MDA-MB-231 and HCC70, which have low eribulin sensitivity. c-Fos expression was not upregulated in other cell lines investigated, including high eribulin-sensitive cells. We hypothesized that c-Fos upregulation is involved in low eribulin sensitivity and thus used the c-Fos inhibitor, T-5224. In MDA-MB-231 and HCC70 cells, combined treatment with eribulin and T-5224 showed a stronger anticancer effect than treatment with eribulin alone in cell growth assays, cell death assays and a mouse xenograft tumor model, whereas T-5224 alone showed no anticancer effect. These results suggest that T-5224 may enhance the anticancer effect of eribulin. Our findings contribute to the improvement of cancer therapy.

Background Osteoporotic fractures constitute a major health concern in both women and men, particularly with the aging population. Many potential risk factors of vertebral fractures (VFx) have been identified in women, but not in men. Several reports have focused on the quality of life (QOL) of clinically diagnosed VFx, but not much has been reported on quantified QOL scores of incidental radiographic VFx in men. This cross-sectional study aimed to investigate the associated factors and the influence of incident radiographic VFx on QOL of men. Methods A total of 401 volunteer men aged 40 years or older (40–92 years) participated in this study. The mean age was 60.5 ± 11.8 years. Prevalent VFx were identified on the lateral lumbar spinal radiographs using the semiquantitative method. Bone mineral density, body composition, smoking, alcohol intake, past medical history, Mini-Mental State Examination, grip strength, gait speed, and biochemical markers were examined. QOL was evaluated using the 36-Item Short-Form Health Survey and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Results Of the 401 subjects, 35 men (8.7%) had the prevalence of VFx. After adjustment for age, the presence of VFx was significantly associated with IGF-1 (odds ratio 0.985; p = 0.02). QOL scores were not significantly associated with VFx after adjustment for age. Conclusions IGF-1 is the mediator of growth hormone, and IGF-1 stimulates the proliferation, differentiation, and mineralization of osteoblastic cells. The prevalence of VFx in men was 8.7%, and IGF-1 was significantly lower in the VFx group than in the non-VFx group.

During metastasis, cancer cell migration is enhanced. However, the mechanisms underlying this process remain elusive. Here, we addressed this issue by functionally analyzing the transcription factor Sal-like 4 (SALL4) in basal-like breast cancer cells. Loss-of-function studies of SALL4 showed that this transcription factor is required for the spindle-shaped morphology and the enhanced migration of cancer cells. SALL4 also up-regulated integrin gene expression. The impaired cell migration observed in SALL4 knockdown cells was restored by overexpression of integrin α6 and β1. In addition, we clarified that integrin α6 and β1 formed a heterodimer. At the molecular level, loss of the SALL4 - integrin α6β1 network lost focal adhesion dynamics, which impairs cell migration. Over-activation of Rho is known to inhibit focal adhesion dynamics. We observed that SALL4 knockdown cells exhibited over-activation of Rho. Aberrant Rho activation was suppressed by integrin α6β1 expression, and pharmacological inhibition of Rho activity restored cell migration in SALL4 knockdown cells. These results indicated that the SALL4 - integrin α6β1 network promotes cell migration via modulation of Rho activity. Moreover, our zebrafish metastasis assays demonstrated that this gene network enhances cell migration in vivo. Our findings identify a potential new therapeutic target for the prevention of metastasis, and provide an improved understanding of cancer cell migration., 乳がん細胞の転移を促進する新たなメカニズムの解明 --SALL4 - integrin α6β1系による移動能力の亢進--. 京都大学プレスリリース. 2016-11-08.

Among breast cancer subtypes, basal-like breast cancer is particularly aggressive, and research on the molecules involved in its pathology might contribute to therapy. In this study, we found that expression of NKX6.1, a homeobox transcription factor, is higher in basal-like breast cancer than in other subtypes. In loss-of-function experiments on basal-like breast cancer cell lines, NKX6.1-depleted cells exhibited reduced cell growth. Because cytokine interleukin-6 (IL-6) is expressed in basal-like breast cancer, and increases cell growth, we analyzed expression levels of IL6, an IL-6 gene, and observed reduced IL6 expression in NKX6.1-depleted cells. In a reporter assay, IL6 promoter activity was reduced by loss of NKX6.1 function. A pull-down assay showed that NKX6.1 binds to the proximal region in IL6 promoter. These results indicate that NKX6.1 directly up-regulates IL6 expression. To investigate further, we established cells with forced expression of IL-6. We observed that exogenous IL-6 expression restored the reduced cell growth of NKX6.1-depleted cells. Furthermore, orthotopic xenografts showed that NKX6.1-depleted cells lost the capacity for tumor formation. We therefore conclude that NKX6.1 is a factor for IL-6-regulated growth and tumor formation in basal-like breast cancer. Our findings facilitate profound understanding of basal-like breast cancer, and the development of suitable therapy.