In Vitro and In Silico Analysis of Epithelial-Mesenchymal Transition and Cancer Stemness as Prognostic Markers of Clear Cell Renal Cell Carcinoma

The process of epithelial-mesenchymal transition (EMT) involves the phenotypic transformation of cells from epithelial to mesenchymal status. The cells exhibiting EMT contain features of cancer stem cells (CSC), and the dual processes are responsible for progressive cancers. Activation of hypoxia-inducible factors (HIF) is fundamental to the pathogenesis of clear cell renal cell carcinoma (ccRCC), and their role in promoting EMT and CSCs is crucial for ccRCC tumour cell survival, disease progression, and metastatic spread. In this study, we explored the status of HIF genes and their downstream targets, EMT and CSC markers, by immunohistochemistry on in-house accrued ccRCC biopsies and adjacent non-tumorous tissues from patients undergoing partial or radical nephrectomy. In combination, we comprehensively analysed the expression of HIF genes and its downstream EMT and CSC-associated targets relevant to ccRCC by using publicly available datasets, the cancer genome atlas (TCGA) and the clinical proteome tumour analysis consortium (CPTAC). The aim was to search for novel biological prognostic markers that can stratify high-risk patients likely to experience metastatic disease. Using the above two approaches, we report the development of novel gene signatures that may help to identify patients at a high risk of developing metastatic and progressive disease.

Knock down of TIMP-2 by siRNA and CRISPR/Cas9 mediates diverse cellular reprogramming of metastasis and chemosensitivity in ovarian cancer

BACKGROUND

The endogenous tissue inhibitor of metalloproteinase-2 (TIMP-2), through its homeostatic action on certain metalloproteinases, plays a vital role in remodelling extracellular matrix (ECM) to facilitate cancer progression. This study investigated the role of TIMP-2 in an ovarian cancer cell line in which the expression of TIMP-2 was reduced by either siRNA or CRISPR/Cas9.

METHODS

OVCAR5 cells were transiently and stably transfected with either single or pooled TIMP-2 siRNAs (T2-KD cells) or by CRISPR/Cas9 under the influence of two distinct guide RNAs (gRNA1 and gRNA2 cell lines). The expression of different genes was analysed at the mRNA level by quantitative real time PCR (qRT-PCR) and at the protein level by immunofluorescence (IF) and western blot. Proliferation of cells was investigated by 5-Ethynyl-2'-deoxyuridine (EdU) assay or staining with Ki67. Cell migration/invasion was determined by xCELLigence. Cell growth in vitro was determined by 3D spheroid cultures and in vivo by a mouse xenograft model.

RESULTS

Approximately 70-90% knock down of TIMP-2 expression were confirmed in T2-KD, gRNA1 and gRNA2 OVCAR5 ovarian cancer cells at the protein level. T2-KD, gRNA1 and gRNA2 cells exhibited a significant downregulation of MMP-2 expression, but concurrently a significant upregulation in the expression of membrane bound MMP-14 compared to control and parental cells. Enhanced proliferation and invasion were exhibited in all TIMP-2 knocked down cells but differences in sensitivity to paclitaxel (PTX) treatment were observed, with T2-KD cells and gRNA2 cell line being sensitive, while the gRNA1 cell line was resistant to PTX treatment. In addition, significant differences in the growth of gRNA1 and gRNA2 cell lines were observed in in vitro 3D cultures as well as in an in vivo mouse xenograft model.

CONCLUSIONS

Our results suggest that the inhibition of TIMP-2 by siRNA and CRISPR/Cas-9 modulate the expression of MMP-2 and MMP-14 and reprogram ovarian cancer cells to facilitate proliferation and invasion. Distinct disparities in in vitro chemosensitivity and growth in 3D culture, and differences in tumour burden and invasion to proximal organs in a mouse model imply that selective suppression of TIMP-2 expression by siRNA or CRISPR/Cas-9 alters important aspects of metastasis and chemosensitivity in ovarian cancer.

Expression of TIMPs and MMPs in Ovarian Tumors, Ascites, Ascites-Derived Cells, and Cancer Cell Lines: Characteristic Modulatory Response Before and After Chemotherapy Treatment

Background

The tissue inhibitors of metalloproteinase (TIMPs) and their associated metalloproteinase (MMPs) are essential regulators of tissue homeostasis and are essential for cancer progression. This study analyzed the expression of TIMP-1,-2,-3 and the associated MMPs (MMP-2,-9,-11,-14) in different Stages, Grades and World Health Organization (WHO) classifications of serous ovarian tumors, ascites, ascites-derived cells from chemo-naïve (CN) and relapsed (CR) patients, and in ovarian cancer cell lines. The status of TIMPs and associated MMPs in response to chemotherapy treatment was assessed in cancer cell lines; TCGA data was interrogated to gauge TIMPs and associated MMPs as prognostic and platinum-response indicators.

Methods

The levels of TIMP-1, -2 and -3 were assessed by immunohistochemistry. The mRNA expression of TIMPs and MMPs was quantified by real time PCR (qRT-PCR). The chemosensitivity (IC₅₀ values) to Cisplatin or Paclitaxel in cell lines was evaluated by MTT assay. The levels of TIMPs in ascites and cell lysates were analyzed by an ELISA assay.

Results

The expression of TIMP-2 was significantly upregulated in Type 2 compared to Type 1 tumors and normal/benign ovarian tissues. TIMP-3 expression was significantly enhanced in Stage III, Grade 3 and Type 2 tumors compared to normal/benign ovarian tissues. The mRNA expression of MMP-9,-11 and -14 was significantly upregulated in Stage IV compared to normal/benign ovarian tissues. The expression of TIMP-1 was highest, followed by TIMP-2 and then TIMP-3 in CN ascites. At the cellular level, TIMP-2 mRNA expression was significantly higher in CN compared to CR epithelial cells in patients. The expression of TIMP-1 and -2, MMPs and cancer stem cells (CSCs) were upregulated in response to chemotherapy treatments in cancer cell lines. Interrogation of the TCGA dataset suggests shifts in platinum responses in patients consistent with genetic alterations in TIMP-2, -3 and MMP-2, -11 genes in tumors; and decreased overall survival (OS) and progression-free survival (PFS) in patients with altered MMP-14 genes.

Conclusions

TIMPs and related MMPs are differentially expressed in serous ovarian tumors, ascites, ascites-derived cells and ovarian cancer cell lines. Chemotherapy treatment modulates expression of TIMPs and MMPs in association with increased expression of genes related to cancer stem cells.

TIMP-2 regulates proliferation, invasion and STAT3-mediated cancer stem cell-dependent chemoresistance in ovarian cancer cells

BACKGROUND

The metzincin family of metalloproteinases and the tissue inhibitors of metalloproteinases (TIMPs) are essential proteins required for biological processes during cancer progression. This study aimed to determine the role of TIMP-2 in ovarian cancer progression and chemoresistance by reducing TIMP-2 expression in vitro in Fallopian tube secretory epithelial (FT282) and ovarian cancer (JHOS2 and OVCAR4) cell lines.

METHODS

FT282, JHOS2 and OVCAR4 cells were transiently transfected with either single or pooled TIMP-2 siRNAs. The expression of different genes after TIMP-2 knock down (T2-KD) or in response to chemotherapy was determined at the mRNA level by quantitative real time PCR (qRT-PCR) and at the protein level by immunofluorescence. Sensitivity of the cell lines in response to chemotherapy after TIMP-2 knock down was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-Ethynyl-2'-deoxyuridine (EdU) assays. Cell invasion in response to TIMP-2 knockdown was determined by xCELLigence.

RESULTS

Sixty to 90 % knock down of TIMP-2 expression was confirmed in FT282, OVCAR4 and JHOS2 cell lines at the mRNA and protein levels. TIMP-2 knock down did not change the mRNA expression of TIMP-1 or TIMP-3. However, a significant downregulation of MMP-2 in T2-KD cells occurred at both the protein and activation levels, compared to Control (Cont; scrambled siRNA) and Parental cells (P, transfection reagent only). In contrast, membrane bound MT1-MMP protein levels were significantly upregulated in T2-KD compared to Cont and P cells. T2-KD cells exhibited enhanced proliferation and increased sensitivity to cisplatin and paclitaxel treatments. Enhanced invasion was observed in the T2-KD-JOSH2 and OVCAR4 cells but not in T2-KD-FT282 cells. Treatment with cisplatin or paclitaxel significantly elevated the expression of TIMP-2 in Cont cells but not in T2-KD cells, consistent with significantly elevated expression of chemoresistance and CSC markers and activation of STAT3. Furthermore, a potent inhibitor of STAT3 activation, Momelotinib, suppressed chemotherapy-induced activation of P-STAT3 in OVCAR4 cells with concomitant reductions in the expression of chemoresistance genes and CSC markers.

CONCLUSIONS

The above results suggest that TIMP-2 may have a novel role in ovarian cancer proliferation, invasion and chemoresistance.

The Many Facets of Metzincins and Their Endogenous Inhibitors: Perspectives on Ovarian Cancer Progression

Approximately sixty per cent of ovarian cancer patients die within the first five years of diagnosis due to recurrence associated with chemoresistance. The metzincin family of metalloproteinases is enzymes involved in matrix remodeling in response to normal physiological changes and diseased states. Recently, there has been a mounting awareness of these proteinases and their endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), as superb modulators of cellular communication and signaling regulating key biological processes in cancer progression. This review investigates the role of metzincins and their inhibitors in ovarian cancer. We propose that understanding the metzincins and TIMP biology in ovarian cancer may provide valuable insights in combating ovarian cancer progression and chemoresistance-mediated recurrence in patients.

Labor-Associated Regulation of Prostaglandin E and F Synthesis and Action in the Ovine Amnion and Cervix

OBJECTIVE

Prostaglandins (PGs) are key regulators of cervical dilatation and membrane breakdown at the onset of labor. PG synthase and receptor expression has been previously documented in uterine tissues; however, mechanisms governing the changes occurring in the cervix and amnion are less well established. The aim of the current study was to determine the level of expression of PG synthetic enzymes and receptors in these tissues in association with induced labor in sheep.

METHODS

Labor was induced in sheep at 135 days of gestation by continuous fetal dexamethasone infusion. Amnion and cervical tissue was obtained before and after labor for measurement of mRNA encoding enzymes (cytosolic phospholipase A2 [cPLA2], PGH synthase-2 [PGHS-2], PGF synthase [PGFS], and PGE synthase [PGES]) and receptors (FP and EP1-4) by real-time polymerase chain reaction (PCR).

RESULTS

cPLA2 expression increased significantly in cervical tissue at labor onset, whereas expression of the other enzymes measured did not change. There was a marked rise in EP3 expression in the cervix, but abundance of this receptor was lower than EP2 and FP expression, which did not change. The amnion exhibited a labor-associated decrease in PGHS-2, PGFS, and FP mRNA expression.

CONCLUSION

The regulation of PG synthesis and action occurring in the amnion and cervix in association with labor appear to differ markedly between the two tissues, indicating tissue-specific roles for PGs. The data support a role for increased PG synthesis and action in the cervix and suggest a decrease in PG production and action in the amnion, in sharp contrast to the pattern reported in human amnion.

Fetal testis dysgenesis and compromised Leydig cell function in Tgfbr3 (beta glycan) knockout mice

Betaglycan (Tgfbr3) is a coreceptor for transforming growth factor-beta (TGFB) superfamily ligands. In the current study, a defect in seminiferous cord formation was detected in 12.5-13.5 days postcoitum (dpc) beta glycan null murine testis. Immunohistochemistry with antibodies against cell-specific markers revealed defects in somatic cell populations. To confirm these data, quantitative real-time PCR was performed to determine changes in the expression levels of genes involved in fetal testis cell differentiation and function. The expression levels of the Leydig cell markers Insl3, Cyp17a1, Cyp11a1, Star, and Hsd3b1 were reduced in knockout testis compared to wild-type testis, beginning at 12.5 dpc. Whole mount in situ hybridization confirmed that Cyp11a1 expression was reduced in the null testis, but its distribution pattern was unchanged. Apoptosis was not affected by the loss of beta glycan, but proliferation within the interstitium was reduced at 14.5 dpc. However, morphometric analysis showed no changes in Leydig cell counts between the wild-type and the knockout testes at 14.5 dpc, indicating that fetal Leydig function, rather than number, was affected by the loss of beta glycan. The expression levels of Sertoli cell markers Dhh, Sox9, and Amh were also reduced in the knockout testis at 14.5 dpc. However, the expression of fetal germ cell markers Pou5f1 and DDX4 were not changed across the genotypes at any age examined. Our data show that the presence of beta glycan is required for normal cord formation, normal fetal Leydig cell development, and the establishment of fetal testis endocrine function, thus implicating TGFB superfamily members as regulators of early fetal testis structure and function.

Reducing betaglycan expression by RNA interference (RNAi) attenuates inhibin bioactivity in LbetaT2 gonadotropes

Betaglycan is an inhibin-binding protein co-receptor, the forced expression of which confers inhibin responsiveness on cells previously non-responsive to inhibin. The present study determines whether removal of betaglycan expression in otherwise inhibin-responsive cells will render the cells insensitive to inhibin. Small interfering RNAs (siRNAs) designed to the betaglycan gene were transfected into LbetaT2 gonadotrope cells to 'knock-down' betaglycan expression. To control for non-specific effects, siRNAs corresponding to an unrelated sequence (BF-1) were used. Two activin-responsive promoter constructs were used to assess inhibin bioactivity; an ovine FSHbeta promoter (oFSHbeta-lux), and a construct containing three copies of the activin-responsive sequence from the GnRHR promoter (3XpGRAS-PRL-lux). Activin stimulated the activity of both promoters 5-8-fold. Inhibin suppressed these activin-stimulated promoter activities by 52+/-11% and 51+/-7%, respectively. Similar inhibin suppression was also seen for cells co-transfected with the control BF-1 siRNAs. In contrast, inhibin's ability to suppress activin-stimulated activity was significantly reduced (33+/-3%, p<0.005 and 24+/-4%, p<0.045, respectively) in cells co-transfected with betaglycan siRNAs. These results demonstrated that endocrine effects of inhibin as a negative feedback controller of FSH production in gonadotropes are dependent on betaglycan expression.

Loss of betaglycan contributes to the malignant properties of human granulosa tumor cells

Betaglycan is a type III TGFbeta receptor that modulates cellular sensitivity to inhibins and TGFbeta. Previous studies have suggested that betaglycan acts as a tumor suppressor in certain human epithelial cancers. However, the roles of betaglycan in ovarian granulosa cell tumors (GCTs) are poorly understood. The objective of this study was to determine whether human GCTs exhibit betaglycan expression and, if so, what impact this receptor has on tumor biology. Real-time PCR was used to quantify betaglycan transcripts in human GCTs (n = 17) and normal premenopausal ovaries (n = 11). This analysis established that GCTs exhibited a significant 2-fold lower mean betaglycan mRNA level as compared with the normal ovary (P < 0.05). Similarly, two human GCT cell lines, KGN and COV434, exhibited low betaglycan expression and poor responsiveness to TGFbeta and inhibin A in luciferase reporter assays, which was restored by stable transfection of wild-type betaglycan. Betaglycan significantly increased the adhesion of COV434 (P < 0.05) and KGN (P < 0.0001) cells, decreased cellular invasion through Matrigel, and inhibited wound healing. Expression of mutant forms of betaglycan that are defective in TGFbeta and/or inhibin binding in each GCT cell line revealed that the inhibitory effects of betaglycan on wound healing were most strongly linked to the inhibin-binding region of betaglycan. Furthermore, knockdown of INHA mRNA expression abrogated the betaglycan-mediated inhibition of wound healing and invasion, whereas both INHA silencing and TGFbeta neutralization abolished the betaglycan-mediated increase in adhesion to substrate. These data suggest that loss of betaglycan contributes to the pathogenesis of GCTs.

Prostaglandin E and F Receptor Expression and Myometrial Sensitivity at Labor Onset in the Sheep1

Prostaglandins (PGs) play a pivotal role in the initiation and progression of term and preterm labor. Uterine activity is stimulated primarily by PGE(2) and PGF(2alpha) acting on prostaglandin E (EP) and prostaglandin F (FP) receptors, respectively. Activation of FP receptors strongly stimulates the myometrium, whereas stimulation of EP receptors may lead to contraction or relaxation, depending on the EP subtype (EP1-4) expression. Thus, the relative expression of FP and EP1-4 may determine the responsiveness to PGE(2) and PGF(2alpha). The aims of this study were to characterize the expression of EP1-4 and FP in intrauterine tissues and placentome, together with myometrial responsiveness to PG, following the onset of dexamethasone-induced preterm and spontaneous term labor. Receptor mRNA expression was measured using quantitative real-time polymerase chain reaction using species-specific primers. There was no increase in myometrial contractile receptor expression at labor onset, nor was there a change in sensitivity to PGE(2) and PGF(2alpha). This suggests expression of these receptors reaches maximal levels by late gestation in sheep. Placental tissue showed a marked increase in EP2 and EP3 receptor expression, the functions of which are unknown at this time. Consistent with previous reports, these results suggest that PG synthesis is the main factor in the regulation of uterine contractility at labor. This is the first study to simultaneously report PG E and F receptor expression in the key gestational tissues of the sheep using species-specific primers at induced-preterm and spontaneous labor onset.

Pituitary cell lines and their endocrine applications

The pituitary gland is an important component of the endocrine system, and together with the hypothalamus, exerts considerable influence over the functions of other endocrine glands. The hypothalamus either positively or negatively regulates hormonal productions in the pituitary through its release of various trophic hormones which act on specific cell types in the pituitary to secrete a variety of pituitary hormones that are important for growth and development, metabolism, reproductive and nervous system functions. The pituitary is divided into three sections-the anterior lobe which constitute the majority of the pituitary mass and is composed primarily of five hormone-producing cell types (thyrotropes, lactotropes, corticotropes, somatotropes and gonadotropes) each secreting thyrotropin, prolactin, ACTH, growth hormone and gonadotropins (FSH and LH) respectively. There is also a sixth cell type in the anterior lobe-the non-endocrine, agranular, folliculostellate cells. The intermediate lobe produces melanocyte-stimulating hormone and endorphins, whereas the posterior lobe secretes anti-diuretic hormone (vasopressin) and oxytocin. Representative cell lines of all the six cell types of the anterior pituitary have been established and have provided valuable information on genealogy of the various cell lineages, endocrine feedback control of hormone synthesis and secretions, intrapituitary interactions between the various cell types, as well as the role of specific transcription factors that determine each differentiated cell phenotype. In this review, we will discuss the morphology and function of the cell types that make up the anterior pituitary, and the characteristics of the various functional anterior pituitary cell systems that have been established to be representative of each anterior pituitary cell lineage.

Changes in the expression of prostaglandin E and F synthases at induced and spontaneous labour onset in the sheep

The differential production of prostaglandin (PG) F(2 alpha) and PGE(2) within the uterine compartment may play a role in controlling myometrial contraction. We hypothesized that the enzymes downstream of PG endoperoxide synthase-2 (PGHS-2) determine the ratio of PGF(2 alpha) and PGE(2) in the utero-ovarian vein plasma and the time of normal and preterm labour onset. The aim of this study was to simultaneously determine the expression of PGF and PGE synthases (PGFS and PGES) in gestational tissues at spontaneous and induced-preterm labour in sheep. Myometrial, endometrial and placental tissue were obtained from ewes in dexamethasone-induced preterm labour, age-matched control ewes, and ewes in spontaneous term labour for analysis of mRNA expression by real-time PCR. PGFS mRNA expression was significantly increased following dexamethasone-induced and spontaneous labour onset in placentome (P<0.01) but was unchanged in the myometrium and endometrium. In contrast, PGES mRNA expression remained unchanged or decreased. PGHS-2 mRNA expression was increased in all tissues examined in both dexamethasone-induced and spontaneous labour (P<0.001). Plasma PGE(2) and PGF(2 alpha) concentrations rose in both dexamethasone-induced and spontaneous labour with the ratio of PGF(2 alpha):PGE(2) increased with labour onset (P<0.05). These results are consistent with the hypothesis that the increased expression, of PGFS is responsible for the increased PGF(2 alpha):PGE(2) ratio and this, together with increased PGHS-2 expression, accounts for myometrial activity at labour onset. The findings point to PGFS expression as a key factor in regulating the uterotonic process in the sheep.