Expression of Interactive Genes Associated with Apoptosis and Their Prognostic Value for Ovarian Serous Adenocarcinoma.

BACKGROUND: Malignant ovarian tumor is one of the leading causes of worldwide cancer death. It is usually characterized by insidious onset and late diagnosis because of the absence of symptoms, allowing ovarian cancer cases to progress rapidly and become unresectable. The tumor suppressor, p53, plays an important role in regulating cell cycles and apoptosis. p53 is regulated by several molecules, and it interacts with other apoptotic proteins. OBJECTIVES: To compare the prognosis of ovarian serous carcinoma and evaluate the expression of DNA-PKcs, Akt3, GSK-3ß, and p53 in cancerous cells. MATERIAL AND METHODS: DNA-PKcs, Akt3, GSK-3ß, and p53 expression levels were scored using immunohistochemistry staining of tissue samples from 132 women with ovarian serous adenocarcinoma. Expression was confirmed by real-time RT-PCR. Analyses were stratified by age, tumor grades, cancer stages and serum CA 125 levels. RESULTS: Significant differences in DNA-PKcs, Akt3, and p53 expression were observed between participants with different stages and tumor grades of ovarian serous adenocarcinoma. DNA-PKcs and p53 expression increased along with increasing tumor grade. Meanwhile, DNA-PKcs, Akt3, and p53 expression increased along with increasing cancer stage, and with a decrease in 5-year overall survival rate. CONCLUSIONS: This study shows that elevated expression of DNA-PKcs, Akt3, and p53 in ovarian serous adenocarcinoma tissues are an indication of more advanced disease and worse prognosis.

Detection of angiogenic factors in midtrimester amniotic fluid and the prediction of preterm birth.

OBJECTIVE: We investigated whether the level of vascular endothelial growth factor (VEGF), placental growth factor (PlGF), and soluble VEGF receptor-1 (sFlt-1) in midtrimester amniotic fluid of preterm birth have different values compared with term delivery. MATERIALS AND METHODS: Our participants were 86 pregnant women who had undergone amniocentesis from 16 to 19 weeks of gestation. Forty-three cases were women with preterm delivery, and the other 43 cases were matched women with full-term delivery. Stored amniotic fluid was investigated after the delivery. The levels of VEGF, PlGF, and sFlt-1 were measured by enzyme-linked immunosorbent assay and Western blot. RESULTS: The levels of VEGF and PlGF in the preterm group were significantly higher than in the control group (30.48 ± 8.57 pg/mL vs. 26.06 ± 8.24 pg/mL and 28.83 ± 7.83 pg/mL vs. 25.35 ± 8.26 pg/mL, respectively) (p = 0.017 and 0.048, respectively). In terms of sFlt-1, the levels were decreased in the preterm group (10,478.51 ± 4012.56 pg/mL vs. 12,544.05 ± 4140.96 pg/mL) (p = 0.021). CONCLUSION: This study explains that elevated levels of VEGF and PlGF, suggestive of angiogenesis and tendency of inflammation at midtrimester, are predictive of preterm delivery, and their availability is maximized by downregulation of sFlt-1.

An unusual case of pedunculated subserosal leiomyosarcoma of the uterus mimicking ovarian carcinoma.

BACKGROUND: Leiomyosarcoma of the uterus is an extremely rare but highly aggressive tumor that accounts for only 1-2 % of uterine malignancies, and is usually associated with a dismal outcome. CASE PRESENTATION: The authors present an unusual case of pedunculated subserosal leiomyosarcoma of the uterus mimicking ovarian carcinoma. A 57-year-old postmenopausal woman presented with progressive low abdominal pain and urinary frequency. Pelvic magnetic resonance imaging revealed a large adnexal mass with carcinomatosis peritonei. Laboratory examination revealed an elevated serum CA-125 level (398.4 U/ml). The patient underwent exploratory laparotomy under suspicion of ovarian malignancy. Frozen section indicated malignancy originating from the uterus, and thus, total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, pelvic and para-aortic lymph node dissection, and mass excision were performed. Subsequent histopathologic examination resulted in a final diagnosis of leiomyosarcoma of the uterus. The patient's postoperative course was uneventful, and gemcitabine and docetaxel adjuvant chemotherapy was administered. CONCLUSION: The authors report an unusual case of pedunculated subserosal leiomyosarcoma of the uterus mimicking ovarian carcinoma.

Ruptured Hemorrhagic Corpus Luteum Cyst in an Undescended Ovary: A Rare Cause of Acute Abdomen.

BACKGROUND: Undescended ovaries are typically detected during infertility evaluations and are frequently associated with uterine malformations. Ruptured hemorrhagic corpus luteum cyst of an undescended ovary is an unusual cause of acute abdomen in an adolescent. CASE: A 15-year-old girl presented with right lower quadrant pain, nausea, and vomiting, and transabdominal sonography and magnetic resonance imaging of the pelvis showed a 10 cm × 5 cm sized cystic mass at the level of the pelvic brim, anterior to the psoas muscle suggestive of a retroperitoneal hemorrhagic cyst. At surgery, the uterus and left adnexa appeared normal, but the right ovary was not visible within the pelvic cavity, and the right pelvic retroperitoneum was distended. After opening the retroperitoneum and aspirating blood clots, the undescended ovary with a ruptured cyst was visualized within the retroperitoneum. Right ovarian wedge resection was performed and the right ovary was repositioned in the pelvic cavity. SUMMARY AND CONCLUSION: Rupture of a corpus luteum cyst in an undescended ovary should be included in the differential diagnosis of acute abdomen in adolescents.

Changes in bone density after cancer treatment in patients with cervical and endometrial cancer.

OBJECTIVE: This study aimed to evaluate the impact of cancer treatment on bone mineral density (BMD) in the lumbar spine (LS) and femur in the postmenopausal women with cervical or endometrial cancer without bone metastasis compared to normal control postmenopausal women. METHODS: We retrospectively evaluated the BMD data in the LS, femur neck (FN) and trochanter (FT) by dual-energy X-ray absorptiometry and laboratory data of bone turnover markers at baseline and after one year in 130 patients with cervical cancer, 68 patients with endometrial cancer, and 225 healthy controls. RESULTS: There were no significant differences in the T-scores of basal BMD in LS and femur between patients with endometrial cancer and controls, and only T-score of basal BMD at the fourth lumbar vertebra (L4) was significantly lower in patients with cervical cancer compared to controls. One year later, T-scores of BMD at all LS sites and FN in patients with cervical cancer and T-scores of BMD at L3, L4, FN, and FT in those with endometrial cancer after cancer treatment were significantly lower compared to controls. Lower proportions of normal BMD at all skeletal sites except L2 in patients with endometrial cancer and those at L1, L4, and FN in patients with cervical cancer were observed compared to controls after cancer treatment. CONCLUSIONS: Our results suggest that cancer treatment increase bone loss in postmenopausal women with cervical and endometrial cancer.

The Role of TWIST in Ovarian Epithelial Cancers.

BACKGROUND: Epithelial-mesenchymal transition (EMT) is associated with tumor hypoxia. EMT is regulated, in part, by the action of TWIST, which inhibits of E-cadherin expression and may interfere with the p53 tumor-suppressor pathway. METHODS: We examined the expression of TWIST, E-cadherin, hypoxia-inducible factor 1α (HIF1α), and p53 by immunohistochemistry in 123 cases of ovarian epithelial cancers (OEC) to evaluate the role of TWIST in OEC. We assessed the association between protein expression and clinicopathologic parameters. RESULTS: The expression of TWIST, E-cadherin, HIF1α, and p53 proteins was found in 28.5%, 51.2%, 35.0%, and 29.3% of cases, respectively. TWIST expression was associated with higher histologic grade and unfavorable survival. TWIST expression was correlated with HIF1α expression and reduced E-cadherin expression. The altered HIF1α/TWIST/E-cadherin pathway was associated with lower overall survival (OS), while the co-expression of TWIST and p53 was correlated with lower progression-free survival. In the multivariate analyses, TWIST expression was an independent prognostic factor for OS. CONCLUSIONS: Our data imply that TWIST expression could be a useful predictor of unfavorable prognosis for OEC. TWIST may affect the p53 tumor-suppressor pathway. Moreover, hypoxia-mediated EMT, which involves the HIF1α/TWIST/E-cadherin pathway may play an important role in the progression of OEC.

Tumor-infiltration of T-lymphocytes is inversely correlated with clinicopathologic factors in endometrial adenocarcinoma.

OBJECTIVE: The aim of this study was to determine the distribution of T-lymphocytes and their relationship with clinicopathologic factors in endometrial carcinoma. METHODS: Samples were collected from 89 patients with endometrial endometrioid adenocarcinoma treated in Pusan National University Hospital from 2004 to 2011. Normal endometrial tissues were obtained from 30 hysterectomized women with benign adnexal masses and served as controls. Paraffin-embedded sections were immunohistochemically stained for CD8 (cytotoxic) and CD4 (helper) T-lymphocytes. The relationship of these cells with stage, histological grade, myometrial invasion, and lymph node metastasis was analyzed. RESULTS: The proportion of CD8+ and CD4+ lymphocytes in the endometrial endometrioid adenocarcinoma tissues was 67.4% (60/89) and 44.9% (40/89), respectively, which was significantly higher (P<0.05) than in the control group. The extent of CD8+ lymphocyte expression was negatively correlated with histologic grade, myometrial invasion, and lymph node metastasis. The proportion of infiltration of the CD4+ lymphocytes was negatively correlated with histologic grade and myometrial invasion. CONCLUSION: The high rate of infiltration of T-lymphocytes was negatively correlated with histologic grade, myometrial invasion, and lymph node metastasis. Our findings suggest that tumor-infiltrating T-lymphocytes may be used as pathologic prognostic factors in endometrial carcinoma.

S100 expression in dendritic cells is inversely correlated with tumor grade in endometrial carcinoma.

OBJECTIVE: The aim of this study was to determine the expression of S100 positive dendritic cells (DCs) and the relationship with clinicopathologic factors in endometrial carcinoma. METHODS: Samples were collected from 89 patients with endometrial endometrioid adenocarcinoma treated in Pusan National University Hospital from 2004 to 2011. Normal endometrial tissues were obtained from 30 hysterectomized women with benign adnexal masses and served as controls. Paraffin-embedded sections were immunohistochemically stained for S100 was performed, and the number of positive DCs was counted. The relationship of these cells to the stage, histological grade, myometrial invasion, and lymph node metastasis was analyzed. RESULTS: The proportion of S100-positive DCs in the endometrial endometrioid adenocarcinoma was 31.5% (28/89), which was significantly higher (P<0.05) than in the control group. The proportion of S100-positive DC expression was negatively correlated with the histologic grade, but was not associated with the stage, myometrial invasion, or lymph node metastasis. CONCLUSION: High DC density was inversely correlated with histologic grade in endometrial carcinoma. Tumor-infiltrating S100+ DCs may be used as pathologic marker in endometrial carcinoma.

Prognostic value of cytoplasmic expression of S100A4 protein in endometrial carcinoma.

The S100A4 protein, a member of the S100 family of calcium-binding proteins, has been considered as a candidate prognostic marker in patients with cancer. The present study was conducted to evaluate the prognostic value of S100A4 and to examine its correlation with the clinicopathological parameters and the overall survival and progression-free survival in patients with endometrial carcinoma (EC). To do this, we performed immunohistochemistry of formalin-fixed tissue sections obtained from 135 cases of EC. In addition, we quantified the level of S100A4 mRNA using the quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). The cytoplasmic expression of S100A4 protein was observed in 35 cases (25.9%). There was a significant association between the expression of S100A4 and clinicopathological parameters such as histologic grade, FIGO stage, lymph node metastasis and loss of progesterone receptor (PR). qRT-PCR demonstrated that the level of S100A4 mRNA was significantly higher in ECs as compared with normal endometrium. The cytoplasmic expression of S100A4 had a significant correlation with shorter overall survival and progression-free survival on the Kaplan-Meyer survival analysis. In multivariate analysis, there was a significant correlation between S100A4 expression and a poorer OS. In conclusion, our results indicate that S100A4 may be a biological marker indicating the recurrence and poor prognosis in patients with EC.

DDX4 (DEAD box polypeptide 4) colocalizes with cancer stem cell marker CD133 in ovarian cancers.

DDX4 (DEAD box polypeptide 4), characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), is an RNA helicase which is implicated in various cellular processes involving the alteration of RNA secondary structure, such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. DDX4 is known to be a germ cell-specific protein and is used as a sorting marker of germline stem cells for the production of oocytes. A recent report about DDX4 in ovarian cancer showed that DDX4 is overexpressed in epithelial ovarian cancer and disrupts a DNA damage-induced G2 checkpoint. We investigated the relationship between DDX4 and ovarian cancer stem cells by analyzing the expression patterns of DDX4 and the cancer stem cell marker CD133 in ovarian cancers via tissue microarray. Both DDX4 and CD133 were significantly increased in ovarian cancer compared to benign tumors, and showed similar patterns of expression. In addition, DDX4 and CD133 were mostly colocalized in various types of ovarian cancer tissues. Furthermore, almost all CD133 positive ovarian cancer cells also express DDX4 whereas CD133-negative cells did not possess DDX4, suggesting a strong possibility that DDX4 plays an important role in cancer stem cells, and/or can be used as an ovarian cancer stem cell marker.

Clinicopathological significance of atypical glandular cells on Pap smear.

OBJECTIVE: To investigate the clinical significance of atypical glandular cells (AGC) by analyzing the prevalence and histologic outcomes of patients with AGC according to Pap smear. METHODS: The medical records of 83 patients who were diagnosed AGC on Pap tests at the Pusan National University Hospital outpatient department and health care center from January 1998 to March 2006 were reviewed. RESULTS: The prevalence of AGC was 55 of 54,160 (0.10%) and 28 of 54,160 (0.05%) for AGC-not otherwise specified (NOS) and neoplastic associated AGC, respectively. The histopathologic results of the AGC-NOS group (n=55) were as follows: low-grade squamous intraepithelial lesion, 7 (12.7%); high-grade squamous intraepithelial lesion, 4 (7.2%); adenocarcinoma of cervix, 3 (5.4%); endometrial carcinoma, 2 (3.6%); and other malignancies including 2 ovarian cancer cases and 1 breast cancer case, 3 (5.4%). The histopathologic results for the AGC-associated neoplastic group (n=28) were as follows: low-grade squamous intraepithelial lesion, 1 (3.5%); high-grade squamous intraepithelial lesion, 3 (10.7%); adenocarcinoma of cervix, 5 (17.8%); endometrial carcinoma, 4 (4.8%); and additional malignancies including 3 stomach cancer cases, 2 ovarian cancer cases, and 2 breast cancer cases; 7 (25%). CONCLUSION: AGCs may represent a variety of benign and malignant lesions. AGC-associated neoplastic findings may be related to gynecological or extrauterine malignancies. Thus, when AGCs, especially neoplastic AGCs, are encountered, it is best to evaluate the cervix not only for typical maladies, but also for gynecological and non-gynecological malignancies.

TAZ mediates lysophosphatidic acid-induced migration and proliferation of epithelial ovarian cancer cells.

BACKGROUND: Transcriptional co-activator with PDZ-binding motif (TAZ), a downstream effector of the Hippo pathway, has been reported to regulate organ size, tissue homeostasis, and tumorigenesis by acting as a transcriptional co-activator. Lysophosphatidic acid (LPA) is a bioactive lipid implicated in tumorigenesis and metastasis of ovarian cancer through activation of G protein-coupled receptors. However, the involvement of TAZ in LPA-induced tumorigenesis of ovarian cancer has not been elucidated. METHODS: In order to demonstrate the role of TAZ in LPA-stimulated tumorigenesis, the effects of LPA on TAZ expression and cell migration were determined by Western blotting and chemotaxis analyses in R182 human epithelial ovarian cancer cells. RESULTS AND CONCLUSION: Treatment of R182 cells with the LPA receptor inhibitor Ki16425 blocked LPA-induced cell migration. In addition, transfection of R182 cells with small interfering RNA specific for LPA receptor 1 resulted in abrogation of LPA-stimulated cell migration. LPA induced phosphorylation of ERK and p38 MAP kinase in R182 cells and pretreatment of cells with the MEK-ERK pathway inhibitor U0126, but not the p38 MAPK inhibitor SB202190, resulted in abrogation of LPA-induced cell migration. Pretreatment of R182 cells with U0126 attenuated LPA-induced mRNA levels of TAZ and its transcriptional target genes, such as CTGF and CYR61, without affecting phosphorylation level of YAP. These results suggest that MEK-ERK pathway plays a key role in LPA-induced cell migration and mRNA expression of TAZ in R182 cells, without affecting stability of TAZ protein. In addition, small interfering RNA-mediated silencing of TAZ expression attenuated LPA-stimulated migration of R182 cells. These results suggest that TAZ plays a key role in LPA-stimulated migration of epithelial ovarian cancer cells.

Preferences for and experiences of family involvement in cancer treatment decision-making: patient-caregiver dyads study.

BACKGROUND: Despite the important role that family caregivers play in providing emotional and practical support to cancer patients, relatively little is known about the family caregiver's role in treatment decision-making (TDM). We sought to investigate patients' and family caregivers' preferences for and experiences of family involvement in TDM and factors associated with preference concordance. METHOD: A national survey was performed with 990 patient-caregiver dyads (participation rate:76.2%). Questions examining preferences for and experiences of family involvement in TDM were administered independently to patients and family caregivers. Concordance was calculated with weighted kappa. Logistic regression analyses were used to identify predictors of patients' and caregivers' preferences for family involvement in TDM and concordance between them. RESULTS: Few patients or family caregivers expressed a preference for unilateral decision-making; however, there was considerable variation and poor agreement within dyads in regard to whether the patient or family caregivers should take the lead in decision-making with input from the other (weighted kappa between respondents for TDM preferences and experiences = 0.10 and κ = 0.18, respectively). Greater TDM preference concordance was associated with higher patient education, whereas lower levels of concordance were evident for younger patients, less educated caregivers, adult child patient dyads (as opposed to a spouse-patient dyads) and problematic family communication about cancer. CONCLUSIONS: Most patients and family caregivers valued and expected family involvement in TDM. However, there is little explicit agreement in regard to which party in the dyad should take decisional leadership and who should play a supporting role.

Oncostatin M promotes mesenchymal stem cell-stimulated tumor growth through a paracrine mechanism involving periostin and TGFBI.

Oncostatin M, a member of the interleukin-6 family of cytokines, has been implicated in tumorigenesis of human prostate cancer. In the current study, we demonstrate that oncostatin M promotes human adipose tissue-derived mesenchymal stem cell-stimulated tumor growth in an in vivo xenograft transplantation model of the human prostate cancer cell line PC-3M-luc-C6, a PC3M cell line expressing the luciferase gene. Conditioned medium derived from oncostatin M-treated mesenchymal stem cells stimulated adhesion of PC-3M-luc-C6 cells. We identified TGFBI and periostin, extracellular matrix proteins implicated in tumorigenesis and metastasis, as oncostatin M-induced secreted proteins in mesenchymal stem cells. Treatment with oncostatin M stimulated secretion of periostin and TGFBI from mesenchymal stem cells in a time-dependent manner. Immunodepletion of TGFBI and periostin from conditioned medium derived from oncostatin M-treated mesenchymal stem cells resulted in abrogation of adhesion of PC-3M-luc-C6 cells stimulated by oncostatin M-conditioned medium. In addition, small interfering RNA-mediated silencing of TGFBI and periostin resulted in abrogation of cell adhesion stimulated by oncostatin M-conditioned medium. These results suggest that mesenchymal stem cell-derived TGFBI and periostin play a key role in tumorigenesis by stimulating adhesion of prostate cancer cells.

Correlation between biological marker expression and F-fluorodeoxyglucose uptake in cervical cancer measured by positron emission tomography.

BACKGROUND: This study aimed to determine whether several biologic markers were associated with (18)fluorine-fluorodeoxyglucose ((18)F-FDG) uptake in patients with carcinoma of the cervix. PATIENTS AND METHODS: 60 patients with International Federation of Gynecology and Obstetrics (FIGO) stages IA2 to IIB cervical cancer, who underwent (18)FDG positron emission tomography/computed tomography (PET/CT), were included in the current study. All patients underwent radical hysterectomy. Tumor sections were stained by immunohistochemistry for glucose transporter 1 (GLUT1), carbonic anhydrase-IX (CA-IX), vascular endothelial growth factor (VEGF), hexokinase type I (HK-I), hexokinase type II (HK-II), and cytoplasmic and nuclear hypoxia-inducible factor (HIF) 1α. RESULTS: The expression of GLUT1 (p = 0.005), VEGF (p = 0.021), HK-II (p = 0.009), and cytoplasmic HIF1α (p = 0.024) was significantly associated with a higher median standardized uptake value (SUVmax). There was a positive correlation between (18)F-FDG uptake and GLUT1 (p = 0.008), CA-IX (p = 0.030), HK-II (p < 0.001) as well as cytoplasmic HIF1α (p = 0.016), whereas this relationship was not observed among the VEGF, HK-I and nuclear HIF1α. CONCLUSION: The data presented in this study indicate that (18)F-FDG uptake is associated with the presence of GLUT1, VEGF, nuclear HK-II, and cytoplasmic HIF1α. There was also a significant correlation among the rate of expression of GLUT1, HK-II, cytoplasmic HIF1α, and CAIX in carcinomas of the cervix.

Silibinin inhibits tumor growth through downregulation of extracellular signal-regulated kinase and Akt in vitro and in vivo in human ovarian cancer cells.

Anticancer activity of silibinin, a flavonoid, has been demonstrated in various cancer cell types. However, the underlying mechanisms were not elucidated in human ovarian cancer cells. The present study was undertaken to examine the effect of silibinin in vitro and in vivo on tumor growth in human ovarian cancer cells. Silibinin decreased cell viability in a dose- and time-dependent manner. Silibinin caused an increase in reactive oxygen species (ROS) generation, and the silibinin-induced cell death was prevented by the antioxidant N-acetylcysteine (NAC). Western blot analysis showed silibinin-induced downregulation of extracellular signal-regulated kinase (ERK) and Akt. Transfection of constitutively active forms of MEK and Akt prevented the silibinin-induced cell death. Oral administration of silibinin in animals with subcutaneous A2780 cells reduced tumor volume. Subsequent tumor tissue analysis showed that silibinin treatment induced a decrease in Ki-67-positive cells, an increase in transferase-mediated dUTP nick end labeling (TUNEL)-positive cells, activation of caspase-3, and inhibition of p-ERK and p-Akt. These results indicate that silibinin reduces tumor growth through inhibition of ERK and Akt in human ovarian cancer cells. These data suggest that silibinin may serve as a potential therapeutic agent for human ovarian cancers.

Expression and significance of the TLR4/MyD88 signaling pathway in ovarian epithelial cancers.

BACKGROUND: Toll-like receptors (TLR) are a family of pattern recognition receptors that constitutes a major part of the innate immune system. The TLR4/(Myeloid differentiation factor 88 (MyD88) signaling pathway has been shown to have oncogenic effects. METHODS: To demonstrate the role of TLR4/MyD88 signaling in ovarian epithelial cancers (OECs), we examined the expression of TLR4, MyD88 and nuclear factor- κB (NF-κB) in OECs. The expression of TLR4, MyD88, and NF-κB was detected by immunohistochemistry, and the relationships between these and clinicopathologic features in 123 cases of OECs were also analyzed. RESULTS: The expression of TLR4, MyD88, and NF-κB in OECs was observed in 46.3% (57/123), 36.6% (45/123) and 65% (80/123) of OEC cases, respectively. The TLR4, MyD88, and NF-κB expressions were associated with the histologic type of OECs, particularly with the clear cell type of OEC. There was no significant correlation between TLR4 or NF-κB expression and histologic grade, tumor size, mitotic count, FIGO (International Federation of Gynecology and Obstetrics) stage, disease recurrence. However, there was a significant correlation between MyD88 expression and FIGO stage, disease recurrence as well as histologic type. In univariate analysis, the expression of TLR4 and MyD88, and the coexpression of TLR4/MyD88 and TLR4/MyD88/NF-κB had a significant impact on the survival of patients with OECs. Only MyD88 expression had an independent prognostic significance in multivariate analysis. CONCLUSIONS: Our findings suggest that the TLR4/MyD88 signaling pathway is associated with the survival of patients with OECs, and that MyD88 is an independent prognostic predictor in patients with OECs. The TLR4/MyD88 signaling pathway may be a mechanism responsible for poor prognosis in patients with clear cell type of OEC.

Lysophosphatidic acid-induced ADAM12 expression mediates human adipose tissue-derived mesenchymal stem cell-stimulated tumor growth.

Lysophosphatidic acid (LPA) is involved in mesenchymal stem cell-stimulated tumor growth in vivo. However, the molecular mechanism by which mesenchymal stem cells promote tumorigenesis remains elusive. In the present study, we demonstrate that conditioned medium from A549 human lung adenocarcinoma cells (A549 CM) induced the expression of ADAM12, a disintegrin and metalloproteases family member, in human adipose tissue-derived mesenchymal stem cells (hASCs). A549 CM-stimulated ADAM12 expression was abrogated by pretreatment of hASCs with the LPA receptor 1 inhibitor Ki16425 or by small interfering RNA-mediated silencing of LPA receptor 1, suggesting a key role for the LPA-LPA receptor 1 signaling axis in A549 CM-stimulated ADAM12 expression. Silencing of ADAM12 expression using small interfering RNA or short hairpin RNA abrogated LPA-induced expression of both α-smooth muscle actin, a marker of carcinoma-associated fibroblasts, and ADAM12 in hASCs. Using a xenograft transplantation model of A549 cells, we demonstrated that silencing of ADAM12 inhibited the hASC-stimulated in vivo growth of A549 xenograft tumors and the differentiation of transplanted hASCs to α-smooth muscle actin-positive carcinoma-associated fibroblasts. LPA-conditioned medium from hASCs induced the adhesion of A549 cells and silencing of ADAM12 inhibited LPA-induced expression of extracellular matrix proteins, periostin and ßig-h3, in hASCs and LPA-conditioned medium-stimulated adhesion of A549 cells. These results suggest a pivotal role for LPA-stimulated ADAM12 expression in tumor growth and the differentiation of hASCs to carcinoma-associated fibroblasts expressing α-smooth muscle actin, periostin, and ßig-h3.

Proteomic identification of ADAM12 as a regulator for TGF-ß1-induced differentiation of human mesenchymal stem cells to smooth muscle cells.

BACKGROUND: Transforming growth factor-ß1 (TGF-ß1) induces the differentiation of human adipose tissue-derived mesenchymal stem cells (hASCs) into smooth muscle cells. Lipid rafts are cholesterol-rich microdomains in cell membranes that reportedly play a key role in receptor-mediated signal transduction and cellular responses. In order to clarify whether lipid rafts are involved in TGF-ß1-induced differentiation of hASCs into smooth muscle cells, we analyzed the lipid raft proteome of hASCs. METHODS AND RESULTS: Pretreatment of hASCs with the lipid raft disruptor methyl-ß-cyclodextrin abrogated TGF-ß1-induced expression of α-smooth muscle actin, a smooth muscle cell marker, suggesting a pivotal role of lipid rafts in TGF-ß1-induced differentiation of hASCs to smooth muscle cells. Sucrose density gradient centrifugation along with a shotgun proteomic strategy using liquid chromatography-tandem mass spectrometry identified 1002 individual proteins as the lipid raft proteome, and 242 of these were induced by TGF-ß1 treatment. ADAM12, a disintegrin and metalloproteases family member, was identified as the most highly up-regulated protein in response to TGF-ß1 treatment. TGF-ß1 treatment of hASCs stimulated the production of both ADAM12 protein and mRNA. Silencing of endogenous ADAM12 expression using lentiviral small hairpin RNA or small interfering RNA abrogated the TGF-ß1-induced differentiation of hASCs into smooth muscle cells. CONCLUSIONS: These results suggest a pivotal role for lipid raft-associated ADAM12 in the TGF-ß1-induced differentiation of hASCs into smooth muscle cells.

Periostin mediates human adipose tissue-derived mesenchymal stem cell-stimulated tumor growth in a xenograft lung adenocarcinoma model.

Mesenchymal stem cells stimulate tumor growth in vivo through a lysophosphatidic acid (LPA)-dependent mechanism. However, the molecular mechanism by which mesenchymal stem cells stimulate tumorigenesis is largely elusive. In the present study, we demonstrate that conditioned medium from A549 human lung adenocarcinoma cells (A549 CM) induces expression of periostin, an extracellular matrix protein, in human adipose tissue-derived mesenchymal stem cells (hASCs). A549 CM-stimulated periostin expression was abrogated by pretreatment of hASCs with the LPA receptor 1 (LPA(1)) inhibitor Ki16425 or short hairpin RNA-mediated silencing of LPA(1), suggesting a key role of the LPA-LPA(1) signaling axis in A549 CM-stimulated periostin expression. Using a xenograft transplantation model of A549 cells, we demonstrated that co-injection of hASCs potentiated tumor growth of A549 cells in vivo and that co-transplanted hASCs expressed not only periostin but also α-smooth muscle actin (α-SMA), a marker of carcinoma-associated fibroblasts. Small interfering RNA- or short hairpin RNA-mediated silencing of periostin resulted in blockade of LPA-induced α-SMA expression in hASCs. In addition, silencing of periostin resulted in blockade of hASC-stimulated growth of A549 xenograft tumors and in vivo differentiation of transplanted hASCs to α-SMA-positive carcinoma-associated fibroblasts. Conditioned medium derived from LPA-treated hASCs (LPA CM) potentiated proliferation and adhesion of A549 cells and short interfering RNA-mediated silencing or immunodepletion of periostin from LPA CM abrogated proliferation and adhesion of A549 cells. These results suggest a pivotal role for hASC-secreted periostin in growth of A549 xenograft tumors within the tumor microenvironment.