Psychometric Properties of the Chinese Version of the Sarcopenia and Quality of Life, a Quality of Life Questionnaire Specific for Sarcopenia.

A quality of life questionnaire specific to sarcopenia (SarQoL®) was successfully developed. There is a huge demand for translation and validation in Chinese. The aim of this study was to translate the SarQoL® into Chinese and investigate its psychometric properties. The translation and cross-cultural adaptation process recommended by the developers of the initial questionnaire was followed. A total of 159 participants were investigated. The translation process consists of five steps: (1) two bilinguals independently translate initial English to Chinese; (2) synthesize the two translations into one; (3) backward translations; (4) expert committee review and (5) test of the pre-final version. The validation consists of three parts: (1) validity (discriminative power, construct validity); (2) reliability (internal consistency, test-retest reliability) and (3) floor and ceiling effects. There was no difficulty in translation process. Regarding the validity, good discriminant validity {quality of life for sarcopenic subjects [35.56 (29.73-42.70)] vs. non-sarcopenic ones [73.22 (60.09-82.90)], p < 0.001} and consistent construct validity [high correlations (spearman's r) of SarQoL® with generic Short Form-36 version 2 questionnaire (0.250 to 0.824) and EuroQoL-5-Dimension questionnaire (- 0.114 to - 0.823)] were found in SarQoL®. Regarding reliability, high internal consistency (Cronbach's alpha coefficient was 0.867) and excellent test-retest reliability (intraclass coefficient correlation was 0.997, 95% CI 0.994-0.998) were found. No ceiling/floor effect was reflected. A valid SarQoL® questionnaire is now available for Chinese population. It can provide a better understanding of the sarcopenia disease burden and serve as a therapeutic outcome indicator in research.

Superior-segment Bilateral Facet Violation in Lumbar Transpedicular Fixation, Part I: A Biomechanical Study of Blocking Superior Facets.

STUDY DESIGN: This is an in vitro biomechanical study. OBJECTIVES: The aim of this study was to investigate the biomechanical variations of lumbar spine motor units and that under different moments after screw heads blocking superior-adjacent bilateral facets through the cadaver specimen biomechanical experiment. SUMMARY OF BACKGROUND DATA: Facet joint violation by pedicle screws is not a rare adverse event in instrumented lumbar fusion surgery, and one of the most common types is the screw head blocking the superior-adjacent facet. However, its contribution to biomechanical instability at the supradjacent level is unknown. METHODS: The range of motion (ROM) of 12 lumbar spines (L4-S1) were measured in flexion-extension, lateral bending, and axial rotation for L4/5. All specimens were randomly divided into two groups: the control group and the blocking group, each with 6 specimens. Spine were tested on intact and instrumented specimens, respectively. The relative ROM changes were compared between the blocking and control groups. RESULTS: In the blocking group, the supradjacent-level flexion-extension ROM significantly decreased under all moments (7.5, 6.0, 4.5 Nm) relative to the intact spine and a significant decrease in the lateral bending relative ROM was found at 4.5 Nm. In the control group, no significant change of supradjacent-level ROM was found relative to the intact noninstrumented spine at each moment. When performing flexion-extension, the relative ROM change between the 2 groups was significantly different at 4.5 Nm. When performing lateral bending, the relative ROM change between the 2 groups was significantly different at moments of 6.0 and 4.5 Nm. CONCLUSION: When screw heads blocked superior-adjacent bilateral facets, the supradjacent-level flexion-extension ROM and lateral bending ROM decreased. In the long run, this may be a risk of persistent low-back pain due to frequent impingement. LEVEL OF EVIDENCE: N/A.

Incidence and Risk Factors of Superior Facet Joint Violation in Percutaneous and Open Instrumentation Using Cortical Bone Trajectory Technique: A Comparison of Different Techniques.

STUDY DESIGN: A retrospective study evaluating cranial facet joint violation (FJV) by cortical bone trajectory (CBT) screw. OBJECTIVE: To determine the incidence and risk factors of FJV following CBT screw placement for different techniques. SUMMARY OF BACKGROUND DATA: CBT is a novel technique for lumbar fusion, and FJV is one of the most common complications, leading to poor prognosis. No studies have investigated the incidence and risk factors of FJV for the CBT technique during different methods. METHODS: The authors reviewed 91 consecutive patients who underwent CBT screw instrumentation from June 2015 to August 2018. In the fluoroscopic-open group (FOG), 42 patients received an open procedure. In the navigation-open group (NOG), 24 patients underwent open instrumentation. In the navigation-percutaneous group, 25 patients underwent percutaneous instrumentation. Postoperative computed tomography scans were obtained to determine the degree and incidence of FJV. Clinical and imaging data were analyzed to clarify the risk factors of FJV. RESULTS: The incidence of FJV occurred in 35.7% of patients and 16.9% of screws in the FOG, 4.2% of patients and 3.8% of screws in the NOG, and 8.0% of patients and 8.0% of screws in the navigation-percutaneous group. Open instrumentation using navigation led to a lower risk of FJV compared with the conventional approach. There was no difference in the rate of FJV between percutaneous and open surgery with navigation assistance. Risk factors affecting FJV include: (1) left-side screw, facet angle ≥45 degrees, and scoliosis for fluoroscopy-assisted CBT instrumentation; (2) body mass index ≥30 kg/m, facet angle ≥45 degrees, and scoliosis for navigation-assisted CBT instrumentation. CONCLUSIONS: Lumbar fusion through CBT instrumentation would reduce FJV. Computer-assisted navigation resulted in a lower incidence of FJV. Percutaneous instrumentation with navigation assistance is not a risk factor for FJV. Special care should be taken in patients with body mass index ≥30 kg/m, left-side screw, facet angle ≥45 degrees, and scoliosis. LEVEL OF EVIDENCE: Level III.

Rate and Risk Factors of Superior Facet Joint Violation during Cortical Bone Trajectory Screw Placement: A Comparison of Robot-Assisted Approach with a Conventional Technique.

OBJECTIVE: To compare the incidence and risk factors of superior facet joint violation (FJV) during cortical bone trajectory screw placement in robot-assisted approach versus conventional technique. METHODS: A retrospective study, including 69 patients having cortical bone trajectory (CBT) screw instrumentation for symptomatic degenerated diseases or trauma, was conducted between June 2015 to January 2019. All patients underwent CBT surgery performed by the same team of experienced surgeons. Patients were randomly divided into two groups: a conventional group (CG, 46 cases) and a robot group (RG, 23 cases). The surgical robotic system was used for screw instrumentation in the robot group and the traditional screw instrumentation with fluoroscopic guidance was used in the conventional group. Cortical screws followed a medio-to-lateral path in the transverse plane and a caudal-to-cephalad path in the sagittal plane. Preoperative and postoperative computed tomography (CT) scans were obtained to determine the degree and incidence of FJV. The violation status of facet joint was evaluated according to the modified classification: grade 0, no violation; grade 1, screw shaft, screw head or rod within 1 mm of or abutting the facet joint, but did not enter the articular facet joint; grade 2, screw shaft, screw head or rod clearly in the facet joint. The following factors that may contribute to the occurrence of FJV were analyzed: age, sex, body mass index (BMI), proximal fusion level, fusion length, the side of screw, preoperative vertebral slip, superior facet angle, and degenerative scoliosis. The chi-squared test and Student's t-test were used for analysis of the variables for significance (P < 0.05). RESULTS: FJV occurred in 41.3% of patients in CG and 17.3% of patients in RG. A chi-squared analysis revealed a significantly lower rate of FJV for RG compared with CG (P = 0.04). In the CG, 17 of the 109 cephalad screws were grade 1 (15.6%), and five were grade 2 (4.6%). In the RG, three of the 46 cephalad screws were grade 1 (6.5%), and three were grade 2 (6.5%). There was a statistically significant difference in the incidence of FJV between the left and right screw with fluoroscopy-assisted CBT screw instrumentation (P < 0.05). A significant correlation between scoliosis with the FJV was found in CG (P < 0.05) and in RG (P < 0.05). With regard to superior facet angle, a measurement ≥45° was a significant risk factor of FJV in CG (P < 0.05) and in RG (P < 0.05). CONCLUSIONS: A robot-assisted approach could reduce the incidence of FJV compared with the conventional approach in CBT technique.

Superior-segment Bilateral Facet Violation in Lumbar Transpedicular Fixation, Part III: A Biomechanical Study of Severe Violation.

MINI: In controls, adjacent-level range of motion (ROM) did not change relative to noninstrumented spine at each moment. In severe violation, flexion-extension and rotation ROM of adjacent vertebrae decreased at each moment (7.5, 6.0, 4.5 Nm); lateral bending ROM decreased at 4.5 Nm. Significant differences in movements were found except lateral bending (7.5 Nm). STUDY DESIGN: This is an in vitro biomechanical study. OBJECTIVES: This study aimed to investigate the biomechanical variations of lumbar spine motor units after bilateral facet joint severe violation in cadaver specimens and analyze the biomechanics under different moments. SUMMARY OF BACKGROUND DATA: The incidence of facet joint violation (FJV) is highly variable, and one of the most important factors is the lack of awareness of protection. Until now, the biomechanical effects of FJV remain unclear. METHODS: Biomechanical testing was performed on 12 human cadaveric spines under flexion-extension, lateral bending, and axial rotation loading. After intact analysis, pedicle screws were inserted at L5, and the biomechanical testing was repeated. Full range of motion (ROM) at the proximal adjacent levels under different moments was recorded and normalized to the intact (100%) noninstrumented spine. The relative ROM changes were compared between the control and severe violation groups. RESULTS: The adjacent-level ROM (flexion-extension, lateral bending, axial rotation) did not change significantly in the control group at each moment (7.5, 6.0, 4.5 Nm) compared with the intact noninstrumented spine. In the severe violation group, the supradjacent-level ROM decreased significantly under all moments relative to the intact noninstrumented spine (P < 0.05) except for the ROM of lateral bending at moments of 7.5 and 6.0 Nm. When comparing the ROM between the two groups, there were significant differences in all movements except lateral bending at 7.5 Nm. CONCLUSION: When superior-segment bilateral facet joints are severely violated by screws, the flexion-extension and axial rotation ROM of adjacent vertebrae decreases at each moment (7.5, 6.0, 4.5 Nm), and the lateral bending ROM decreases at 4.5 Nm. LEVEL OF EVIDENCE: N/A.

This is an in vitro biomechanical study. This study aimed to investigate the biomechanical variations of lumbar spine motor units after bilateral facet joint severe violation in cadaver specimens and analyze the biomechanics under different moments. The incidence of facet joint violation (FJV) is highly variable, and one of the most important factors is the lack of awareness of protection. Until now, the biomechanical effects of FJV remain unclear. Biomechanical testing was performed on 12 human cadaveric spines under flexion-extension, lateral bending, and axial rotation loading. After intact analysis, pedicle screws were inserted at L5, and the biomechanical testing was repeated. Full range of motion (ROM) at the proximal adjacent levels under different moments was recorded and normalized to the intact (100%) noninstrumented spine. The relative ROM changes were compared between the control and severe violation groups. The adjacent-level ROM (flexion-extension, lateral bending, axial rotation) did not change significantly in the control group at each moment (7.5, 6.0, 4.5 Nm) compared with the intact noninstrumented spine. In the severe violation group, the supradjacent-level ROM decreased significantly under all moments relative to the intact noninstrumented spine (P < 0.05) except for the ROM of lateral bending at moments of 7.5 and 6.0 Nm. When comparing the ROM between the two groups, there were significant differences in all movements except lateral bending at 7.5 Nm. When superior-segment bilateral facet joints are severely violated by screws, the flexion-extension and axial rotation ROM of adjacent vertebrae decreases at each moment (7.5, 6.0, 4.5 Nm), and the lateral bending ROM decreases at 4.5 Nm. Level of Evidence: N/A.

Comparison of Superior-Level Facet Joint Violations Between Robot-Assisted Percutaneous Pedicle Screw Placement and Conventional Open Fluoroscopic-Guided Pedicle Screw Placement.

OBJECTIVE: To compare the superior-level facet joint violations (FJV) between robot-assisted (RA) percutaneous pedicle screw placement and conventional open fluoroscopic-guided (FG) pedicle screw placement in a prospective cohort study. METHODS: This was a prospective cohort study without randomization. One-hundred patients scheduled to undergo RA (n = 50) or FG (n = 50) transforaminal lumbar interbody fusion were included from February 2016 to May 2018. The grade of FJV, the distance between pedicle screws and the corresponding proximal facet joint, and intra-pedicle accuracy of the top screw were evaluated based on postoperative CT scan. Patient demographics, perioperative outcomes, and radiation exposure were recorded and compared. Perioperative outcomes include surgical time, intraoperative blood loss, postoperative length of stay, conversion, and revision surgeries. RESULTS: Of the 100 screws in the RA group, 4 violated the proximal facet joint, while 26 of 100 in the FG group had FJV (P = 0.000). In the RA group, 3 and 1 screws were classified as grade 1 and 2, respectively. Of the 26 FJV screws in the FG group, 17 screws were scored as grade 1, 6 screws were grade 2, and 3 screws were grade 3. Significantly more severe FJV were noted in the FG group than in the RA group (P = 0.000). There was a statistically significant difference between RA and FG for overall violation grade (0.05 vs 0.38, P = 0.000). The average distance of pedicle screws from facet joints in the RA group (4.16 ± 2.60 mm) was larger than that in the FG group (1.92 ± 1.55 mm; P = 0.000). For intra-pedicle accuracy, the rate of perfect screw position was greater in the RA group than in the FG group (85% vs 71%; P = 0.017). No statistically significant difference was found between the clinically acceptable screws between groups (P = 0.279). The radiation dose was higher in the FG group (30.3 ± 11.3 vs 65.3 ± 28.3 µSv; P = 0.000). The operative time in the RA group was significantly longer (184.7 ± 54.3 vs 117.8 ± 36.9 min; P = 0.000). CONCLUSIONS: Compared to the open FG technique, minimally invasive RA spine surgery was associated with fewer proximal facet joint violations, larger facet to screw distance, and higher intra-pedicle accuracy.

6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase-2 Regulates TP53-Dependent Paclitaxel Sensitivity in Ovarian and Breast Cancers.

PURPOSE: Paclitaxel is an integral component of primary therapy for breast and epithelial ovarian cancers, but less than half of these cancers respond to the drug. Enhancing the response to primary therapy with paclitaxel could improve outcomes for women with both diseases.Experimental Design: Twelve kinases that regulate metabolism were depleted in multiple ovarian and breast cancer cell lines to determine whether they regulate sensitivity to paclitaxel in Sulforhodamine B assays. The effects of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 2 (PFKFB2) depletion on cell metabolomics, extracellular acidification rate, nicotinamide adenine dinucleotide phosphate, reactive oxygen species (ROS), and apoptosis were studied in multiple ovarian and breast cancer cell lines. Four breast and ovarian human xenografts and a breast cancer patient-derived xenograft (PDX) were used to examine the knockdown effect of PFKFB2 on tumor cell growth in vivo. RESULTS: Knockdown of PFKFB2 inhibited clonogenic growth and enhanced paclitaxel sensitivity in ovarian and breast cancer cell lines with wild-type TP53 (wtTP53). Silencing PFKFB2 significantly inhibited tumor growth and enhanced paclitaxel sensitivity in four xenografts derived from two ovarian and two breast cancer cell lines, and prolonged survival in a triple-negative breast cancer PDX. Transfection of siPFKFB2 increased the glycolysis rate, but decreased the flow of intermediates through the pentose-phosphate pathway in cancer cells with wtTP53, decreasing NADPH. ROS accumulated after PFKFB2 knockdown, which stimulated Jun N-terminal kinase and p53 phosphorylation, and induced apoptosis that depended upon upregulation of p21 and Puma. CONCLUSIONS: PFKFB2 is a novel target whose inhibition can enhance the effect of paclitaxel-based primary chemotherapy upon ovarian and breast cancers retaining wtTP53.

Comparison of the One-Time Accuracy of Simulated Freehand and Navigation Simulated Pedicle Screw Insertion.

OBJECTIVE: To compare one-time accuracy rate between simulated freehand (SFH) and navigation simulated (NS) pedicle screw insertion, assuming no second chance to correct screws. METHODS: A simulated, comparative, cross-sectional study was conducted on 69 patients undergoing lumbar spine surgery. An intraoperative registration system captured the planned point of entry and trajectory of pedicle screws for both SFH under direct visualization and NS under navigation-aided visualization. Pedicle screw insertion was simulated for each captured image (370 screws) using Surgimap. Rajasekaran's method helped evaluate the point of entry accuracy and trajectory. RESULTS: Accuracy rate was better for the NS method (97.8%) than for the SFH method (63.8%). Of 370 screws in the SFH group, 134 penetrated the cortex, with 31 resulting in >4 mm penetration. Of 370 screws in the NS group, 8 penetrated the cortex, <4 mm penetration. Of 134 misplaced screws in the SFH group, 64 were due to error in the point of entry, 63 were due to error in the trajectory angle, and 7 were due to both errors. Of 8 errors in the NS group, 7 were due to the point of entry. CONCLUSIONS: Intraoperative navigation had significantly better one-time accuracy of pedicle screw insertion than freehand insertion and should be used to avoid injury to the pedicle and surrounding tissue from screw reinsertion.

Robot-Assisted Versus Fluoroscopy-Assisted Cortical Bone Trajectory Screw Instrumentation in Lumbar Spinal Surgery: A Matched-Cohort Comparison.

OBJECTIVE: The aim of the present study was to compare the accuracy and safety of TiRobot system-assisted with those of fluoroscopy-assisted cortical bone trajectory screw placement in lumbar spinal surgery. METHODS: We included 58 patients who required instrumentation in a retrospective matched-cohort study. The primary outcome measures were the accuracy of screw placement using the modified Gertzbein-Robbins scale and the incidence of proximal facet joint violation. Secondary outcome measures included operative time, intraoperative blood loss, postoperative hospital stay, radiation exposure, and complications. RESULTS: A total of 231 screws were placed (TiRobot group [RG], 86 screws; fluoroscopy group [FG], 145 screws). In the RG, 87.2% of the screws had perfect positions (grade A). The remaining screws were grade B (8.1%) and C (4.7%). In the FG, 66.9% of the screws had perfect positions (grade A). The remaining screws were grade B (20.0%), C (9.0%), and D (4.1%). The proportion of clinically acceptable screws (grade A or B) was greater in the RG than in the FG. In the RG, the most common direction of screw deviation was cephalad endplate and was the vertebral cortex in FG. No difference was found in facet joint violation between the 2 groups. The operative time and blood loss were slightly greater in the RG than in the FG. No statistically significant difference was found in the postoperative hospital stay between the 2 groups. The mean cumulative radiation time was greater for the RG than for the FG, but the radiation exposure to the surgeon was significantly lower in the RG than in the FG. CONCLUSIONS: Robot-assisted screw placement is more accurate and safe compared with fluoroscopy-assisted placement for lumbar spinal cortical bone trajectory instrumentation.

Computer-assisted, minimally invasive transforaminal lumbar interbody fusion: One surgeon's learning curve A STROBE-compliant article.

Minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) is a challenging technique with a long learning curve. We combined computer-assisted navigation and MI TLIF (CAMISS TLIF) to treat lumbar degenerative disease. This study aimed to evaluate the learning curve associated with computer-assisted navigation MI spine surgery (CAMISS) and TLIF for the surgical treatment of lumbar degenerative disease. Seventy four consecutive patients with lumbar degenerative disease underwent CAMISS TLIF between March 2011 and May 2015; all surgeries were performed by a single surgeon. According to the plateau of the asymptote, the initial 25 patients constituted the early group and the remaining patients comprised the latter group. The clinical evaluation data included operative times, anesthesia times, intraoperative blood losses, days until ambulation, postoperative hospital stays, visual analog scale (VAS) leg and back pain scores, Oswestry disability index (ODI) values, Macnab outcome scale scores, complications, radiological outcomes, and rates of conversion to open surgery. The complexity of the cases increased over the series, but the complication rate decreased (12.00%-6.12%). There were significant differences between the early and late groups with respect to the average surgical times and durations of anesthesia, but no differences in intraoperative blood losses, days until ambulation, postoperative hospital stays, complication rate, VAS, ODI, Macnab outcome scale scores, or solid fusion rates. There was no need for conversion to open procedures in either group. Our study showed that a plateau asymptote for CAMISS TLIF was reached after 25 operations. The later patients experienced shorter operative times and anesthesia durations.

Jab1/Csn5-Thioredoxin Signaling in Relapsed Acute Monocytic Leukemia under Oxidative Stress.

Purpose: High levels of ROS and ineffective antioxidant systems contribute to oxidative stress, which affects the function of hematopoietic cells in acute myeloid leukemia (AML); however, the mechanisms by which ROS lead to malignant transformation in relapsed AML-M5 are not completely understood. We hypothesized that alterations in intracellular ROS would trigger AML-M5 relapse by activating the intrinsic pathway.Experimental Design: We studied ROS levels and conducted c-Jun activation domain-binding protein-1 (JAB1/COPS5) and thioredoxin (TRX) gene expression analyses with blood samples obtained from 60 matched AML-M5 patients at diagnosis and relapse and conducted mechanism studies of Jab1's regulation of Trx in leukemia cell lines.Results: Our data showed that increased production of ROS and a low capacity of antioxidant enzymes were characteristics of AML-M5, both at diagnosis and at relapse. Consistently, increased gene expression levels of TRX and JAB1/COPS5 were associated with low overall survival rates in patients with AML-M5. In addition, stimulating AML-M5 cells with low concentrations of hydrogen peroxide led to increased Jab1 and Trx expression. Consistently, transfection of ectopic Jab1 into leukemia cells increased Trx expression, whereas silencing of Jab1 in leukemia cells reduced Trx expression. Mechanistically, Jab1 interacted with Trx and stabilized Trx protein. Moreover, Jab1 transcriptionally regulated Trx. Furthermore, depletion of Jab1 inhibited leukemia cell growth both in vitro and in vivoConclusions: We identified a novel Jab1-Trx axis that is a key cellular process in the pathobiologic characteristics of AML-M5. Targeting the ROS/Jab1/Trx pathway could be beneficial in the treatment of AML-M5. Clin Cancer Res; 23(15); 4450-61. ©2017 AACR.

Angiotensin II Enhances Proliferation and Inflammation through AT1/PKC/NF-κB Signaling Pathway in Hepatocellular Carcinoma Cells.

BACKGROUND/AIMS: The pathogenesis of hepatocellular carcinoma (HCC) is mainly characterized by persistent cycles of liver injury, inflammation, and compensatory hepatocyte proliferation. Angiotensin II (Ang II) behaves as an endogenous pro-inflammatory molecule playing a significant role in HCC, however, the molecular link between Ang II, proliferation and inflammation remains unclear. METHODS: Human HCC cell lines (HepG-2, SMMC-7721, MHCC97-H) were incubated with Ang II at the indicated concentrations for 24, 48, 72 h. MTT, BrdU ELISA, plate colony formation assay, immunohistochemistry, ELISA, small-interfering RNA(siRNA) transfection, quantitative real-time PCR and western blot were applied to assess their functional, morphological and molecular mechanisms in HCC cell lines. RESULTS: High expression of Ang II type 1 receptor (AT1) and low expression of AT2 in HCC cells and tissues were found. Next, Ang II could significantly enhance cell growth and proliferation. Albeit Ang II slightly increased the percentage of HCC cells in the G0/G1 phase using flow cytometry analysis, no statistically significant alterations were shown. Further studies suggested that Ang II could directly induce proliferation associated proteins C-myc and proliferating cell nuclear antigen (PCNA) expressions, and inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and C-reactive protein (CRP) productions in HCC cells. Interestingly, blocking AT1 and AT1 siRNA evidently inhibited Ang II-induced cell proliferation and inflammatory responses in HCC cells. More importantly, these effects may be mediated by AT1/PKC/NF-κB signaling pathway in HCC cell lines. CONCLUSIONS: The results propose that Ang II/AT1/PKC/NF-κB signaling pathway is necessary for proliferation and inflammation of HCC cells, which increases our understanding of the pathogenesis and provides clues for developing new strategies against Ang II-related progress of HCC.

CDK5 Regulates Paclitaxel Sensitivity in Ovarian Cancer Cells by Modulating AKT Activation, p21Cip1- and p27Kip1-Mediated G1 Cell Cycle Arrest and Apoptosis.

Cyclin-dependent kinase 5 (CDK5) is a cytoplasmic serine/ threonine kinase. Knockdown of CDK5 enhances paclitaxel sensitivity in human ovarian cancer cells. This study explores the mechanisms by which CDK5 regulates paclitaxel sensitivity in human ovarian cancers. Multiple ovarian cancer cell lines and xenografts were treated with CDK5 small interfering RNA (siRNA) with or without paclitaxel to examine the effect on cancer cell viability, cell cycle arrest and tumor growth. CDK5 protein was measured by immunohistochemical staining of an ovarian cancer tissue microarray to correlate CDK5 expression with overall patient survival. Knockdown of CDK5 with siRNAs inhibits activation of AKT which significantly correlates with decreased cell growth and enhanced paclitaxel sensitivity in ovarian cancer cell lines. In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1) as well as TP53-dependent transcriptional induction of p21(Cip1) in wild type TP53 cancer cells. Treatment of HEYA8 and A2780 wild type TP53 xenografts in nu/nu mice with CDK5 siRNA and paclitaxel produced significantly greater growth inhibition than either treatment alone. Increased expression of CDK5 in human ovarian cancers correlates inversely with overall survival. CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis. CDK5 inhibition can potentiate paclitaxel activity in human ovarian cancer cells.

Clinically relevant microRNAs in ovarian cancer.

microRNAs (miRNAs/miRs) belong to a class of small noncoding RNAs that can negatively regulate messenger RNA (mRNA) expression of target genes. miRNAs are involved in multiple aspects of ovarian cancer cell dysfunction and the phenotype of ovarian cancer cells can be modified by targeting miRNA expression. miRNA profiling has detected a number of candidate miRNAs with the potential to regulate many important biologic functions in ovarian cancer, but their role still needs to be clarified, given the remarkable heterogeneity among ovarian cancers and the context-dependent role of miRNAs. This review summarizes the data collected from The Cancer Genome Atlas (TCGA) and several other genome-wide projects to identify dysregulated miRNAs in ovarian cancers. Copy number variations (CNVs), epigenetic alterations, and oncogenic mutations are also discussed that affect miRNA levels in ovarian disease. Emphasis is given to the role of particular miRNAs in altering expression of genes in human ovarian cancers with the potential to provide diagnostic, prognostic, and therapeutic targets. Particular attention has been given to TP53, BRCA1/2, CA125 (MUC16), HE4 (WFDC2), and imprinted genes such as ARHI (DIRAS3). A better understanding of the abnormalities in miRNA expression and downstream transcriptional and biologic consequences will provide leads for more effective biomarkers and translational approaches in the management of ovarian cancer.

ATP directed agent, 8-chloro-adenosine, induces AMP activated protein kinase activity, leading to autophagic cell death in breast cancer cells.

BACKGROUND: 8-chloro-adenosine (8-Cl-Ado) is a unique ribonucleoside analog which is currently in a phase I clinical trial for hematological malignancies. Previously, we demonstrated in breast cancer cells that a 3-day treatment with 10 µM 8-Cl-Ado causes a 90% loss of clonogenic survival. In contrast, there was only a modest induction of apoptosis under these conditions, suggesting an alternative mechanism for the tumoricidal activity of 8-Cl-Ado. METHODS: Cellular metabolism, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) pathway signaling, as well as autophagy induction was evaluated in breast cancer cell lines treated with 8-Cl-Ado. The effects of knocking down essential autophagy factors with small interfering RNA on 8-Cl-Ado-inhibited cell survival was assessed in breast cancer cells by examining apoptosis induction and clonogenic survival. In vivo efficacy of 8-Cl-Ado was measured in two breast cancer orthotopic model systems. RESULTS: We demonstrate that in breast cancer cell lines, the metabolism of 8-Cl-Ado results in depletion of endogenous ATP that subsequently induces the phosphorylation and activation of the energy sensor, AMPK. This was associated with an attenuation of mTOR signaling and an induction of the phosphorylation of the autophagy factor, Unc51-like kinase 1 on Ser555. 8-Cl-Ado-mediated induction of autophagy was evident by increased aggregates of microtubule-associated protein 1 light chain 3B (LC3B) which was associated with its conversion to its lipidated form, LC3B-II, p62 degradative flux, and increased formation of acidic vesicular organelles. Additionally, transfection of MCF-7 cells with siRNA to ATG7 or beclin 1 provided partial protection of the cells to 8-Cl-Ado cytotoxicity as measured by clonogenicity. In vivo, 8-Cl-Ado inhibited growth of both MCF-7 and BT-474 xenograft tumors. Moreover, in 9 of 22 BT-474 tumors treated with 100 mg/kg/day 3 times a week, there was an absence of macroscopically detectable tumor after 3 weeks of treatment. CONCLUSIONS: Our data demonstrates that 8-Cl-Ado treatment activates the AMPK pathway leading to autophagy induction of in breast cancer cells, eliciting, in part, its tumoricidal effects. Additionally, 8-Cl-Ado effectively inhibited in vivo tumor growth in mice. Based on this biological activity, we are planning to test 8-Cl-Ado in the clinic for patients with breast cancer.