Phosphatase Of Regenerating Liver-3 Expression Research Articles

Exploiting frequent and specific expression of PRL3 in pediatric solid tumors for first-in-child use of PRL3-zumab humanized antibody

Phosphatase of regenerating liver 3 (PRL3) is a specific tumor antigen overexpressed in a broad range of adult cancer types. However, its physiological expression in pediatric embryonal and mesenchymal tumors and its association with clinical outcomes in children is unknown. We sought to profile the expression of PRL3 in pediatric tumors in relation to survival outcomes, expression of angiogenesis markers, and G-protein-coupled receptor (GPCR)-mitogen-activated protein kinase (MAPK) signaling targets. PRL3-zumab, a first-in-class humanized antibody, was administered in a dose escalation schedule in a first-in-child clinical trial to study toxicity, pharmacokinetics, and clinical outcomes. Among 64 pediatric tumors, PRL3 was most frequently expressed in neuroblastoma (100%), rhabdomyosarcoma and non-rhabdomyosarcoma soft tissue sarcomas (71%), and renal sarcomas (60%) but absent in paired normal tissues. PRL3 was expressed in 75% of relapsed tumors and associated with shorter median event-free survival. Microarray profiling of PRL3-positive tumors showed elevation of angiogenin, TIMP1 and TIMP2, and GPCR-MAPK signaling proteins that commonly interacted with PRL3. The first use of PRL3-zumab in a pediatric patient saw no adverse events. A 28.6% reduction in maximum target lesion diameter was achieved when PRL3-zumab was administered concurrently with hypofractionated radiation. These findings support wider exploration of PRL3 expression in embryonal and mesenchymal tumors and further clinical application of PRL3-zumab in pediatric patients.

The Deubiquitinating Enzyme USP4 Functions as an Oncoprotein in Gastric Cancer and Mediates NF-κB Signaling by Regulating PRL-3 Expression.

It has been reported that ubiquitin specific peptidase 4 (USP4) was functional in several tumors, but its function and mechanism in gastric cancer were still unknown. Bioinformatic tools were used to predict the prognosis of gastric cancer patients and the expression levels of USP4 in gastric cancer. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunoblotting were carried out to detect the messenger RNA (mRNA) and protein levels. Cell viability of gastric cancer was evaluated by Cell Counting Kit-8 (CCK-8) assay. Cell line-derived xenograft models were established to evaluate the tumor growth of gastric cancer. Luciferase assay and immunoblotting were used to determine the activation of nuclear factor kappa B (NF-κB) signaling. The public database Kaplan-Meier Plotter showed that gastric cancer patients with high USP4 expression had a shorter overall survival or post-progression survival than the patients with decreased USP4. Further studies indicated that USP4 was elevated in gastric cancer tumor tissues. In contrast, knockdown of USP4 markedly inhibited gastric cancer cell growth, and suppressed the tumor growth of gastric cancer. Further studies revealed that USP4 knockdown significantly suppressed NF-κB-driven luciferase activity, and inhibited the phosphorylation of NF-κB p65 in gastric cancer cells. Additionally, qRT-PCR analysis showed that USP4 knockdown significantly downregulated the expressions of cyclin D2 (CCND2) and B cell leukemia/lymphoma 2 (BCL2). We also found that USP4 knockdown decreased the expressions of phosphatase of regenerating liver-3 (PRL-3), in contrast, overexpression of PRL-3 attenuated the inhibitory effects of USP4 knockdown on NF-κB signaling and cell viability in gastric cancer cells. Finally, PR-619, which has been proven to inhibit the activities of USP4 and other deubiquitinases, could inhibit cell viability and NF-κB signaling in gastric cancer cells. This study indicated that elevated USP4 predicted a poor index for gastric cancer patients, and mediated gastric cancer cell growth by regulating PRL-3/NF-κB signaling, which suggested USP4 may be a novel therapeutic target for gastric cancer.

The phosphatase PRL-3 affects intestinal homeostasis by altering the crypt cell composition

Expression of the phosphatase of regenerating liver-3 (PRL-3) is known to promote tumor growth in gastrointestinal adenocarcinomas, and the incidence of tumor formation upon inflammatory events correlates with PRL-3 levels in mouse models. These carcinomas and their onset are associated with the impairment of intestinal cell homeostasis, which is regulated by a balanced number of Paneth cells and Lgr5 expressing intestinal stem cells (Lgr5+ ISCs). Nevertheless, the consequences of PRL-3 overexpression on cellular homeostasis and ISC fitness in vivo are unexplored. Here, we employ a doxycycline-inducible PRL-3 mouse strain to show that aberrant PRL-3 expression within a non-cancerous background leads to the death of Lgr5+ ISCs and to Paneth cell expansion. A higher dose of PRL-3, resulting from homozygous expression, led to mice dying early. A primary 3D intestinal culture model obtained from these mice confirmed the loss of Lgr5+ ISCs upon PRL-3 expression. The impaired intestinal organoid formation was rescued by a PRL inhibitor, providing a functional link to the observed phenotypes. These results demonstrate that elevated PRL-3 phosphatase activity in healthy intestinal epithelium impairs intestinal cell homeostasis, which correlates this cellular mechanism of tumor onset with PRL-3-mediated higher susceptibility to tumor formation upon inflammatory or mutational events.Key messages• Transgenic mice homozygous for PRL-3 overexpression die early.• PRL-3 heterozygous mice display disrupted intestinal self-renewal capacity.• PRL-3 overexpression alone does not induce tumorigenesis in the mouse intestine.• PRL-3 activity leads to the death of Lgr5+ ISCs and Paneth cell expansion.• Impairment of cell homeostasis correlates PRL-3 action with tumor onset mechanisms.

Mesenchymal and Phosphatase of Regenerating Liver-3 Status in Circulating Tumor Cells May Serve as a Crucial Prognostic Marker for Assessing Relapse or Metastasis in Postoperative Patients With Colorectal Cancer

INTRODUCTION:Circulating tumor cells (CTCs) and phosphatase of regenerating liver-3 (PRL-3) have been considered to be significant prognostic indicators in metastatic colorectal cancer (CRC). This study discusses the prognostic significance of mesenchymal CTCs with PRL-3 (M+ PRL-3+ CTCs) in postoperative patients with CRC.METHODS:We detected CTC subtypes (including epithelial CTCs, biphenotypic epithelial/mesenchymal CTCs, and mesenchymal CTCs) and PRL-3 in CTCs from the peripheral blood samples of 156 patients. Receiver operating characteristic curve analysis, Kaplan-Meier analysis, and Cox proportional hazards regression analysis were performed to identify the prognostic value of mesenchymal CTCs with PRL-3+. Immunohistochemistry was used to detect the expression of PRL-3 in tumor tissues from some of the patients to explore the connection between CTCs and tissues.RESULTS:All CTCs were positive in all samples, both mesenchymal CTCs and PRL-3–positive cells. The count of mesenchymal and PRL-3+ CTCs was significantly associated with recurrence, and the optimal cutoff value was 2 (area under the curve = 0.690, P < 0.001). In addition, these patients had a significantly shorter median disease-free survival than those who did not fulfill the criteria (8.5 vs 24 months, P < 0.001) according to multivariable and multinomial logistic regression. Immunohistochemistry was applied to explore the associations between PRL-3 expression and significant prognostic risk factors, including recurrence (R = 0.566; P < 0.001), and M+ PRL-3+ status in CTCs (R = 0.452; P = 0.001).DISCUSSION:The status of M+ PRL-3+ in CTCs may serve as a crucial prognostic marker for assessing clinical outcomes in CRC.

Correlation of PRL3 expression with colorectal cancer progression.

To evaluate the relationship between phosphatase of regenerating liver 3 (PRL3) expression and clinical outcome in colorectal cancer (CRC). PRL3, a protein tyrosine phosphatase functions as one of the key regulatory enzymes of various signal transduction pathways. PRL3 is highly expressed in a majority of cancers and is a novel potential therapeutic target. PRL3 expression was evaluated by immunohistochemistry in 167 patients with CRC, 37 patients with no disease, and 26 patients with metastatic CRC (mCRC). Phosphorylated Akt at serine 473 (p-Akt S473) expression was also evaluated by immunohistochemistry in mCRC patients. High expression of PRL3 was correlated with CRC progression, and every one unit increase in PRL3 level contributed to an increase in the rate of death by 1%-1.7%. PRL3 expression was significantly higher in liver metastases compared with primary tumors and showed a significant positive correlation with the expression level of p-Akt S473. PRL3 expression levels associated with CRC progression and metastasis, and positively correlated with activated Akt level in mCRC. Together, these findings indicated that PRL3 might be a potential marker for increased risk of CRC-specific tumor burden and identify PRL3 as an attractive therapeutic target for mCRC treatment.

RETRACTED: Long Noncoding RNA UCA1 Regulates PRL-3 Expression by Sponging MicroRNA-495 to Promote the Progression of Gastric Cancer

Gastric cancer (GC) is among the most frequently occurring malignancies worldwide. In recent years, long noncoding RNAs (lncRNAs) have been widely studied because of their ability to regulate the cellular processes involved with tumorigenesis. The present study aims to investigate the underlying molecular mechanism by which lncRNA urothelial carcinoma-associated 1 (UCA1) influences the progression of GC. Differentially expressed lncRNA UCA1 was initially identified by microarray-based analysis, after which a high expression of UCA1 was determined in GC tissues and cells. It is important to note that UCA1 could upregulate the expression of phosphatase of regenerating liver-3 (PRL-3) by sponging miR-495. The expression of UCA1 and miR-495 was altered in human GC cells to evaluate cell activity in vitro, as well as peritoneal metastasis and tumor formation ability in vivo. Results suggested that increased expression of UCA1 promoted cell proliferation, migration, and invasion, accompanied by suppressed cell apoptosis, as well as enhanced peritoneal metastasis and tumorigenesis of GC cells. Meanwhile, the upregulated expression of miR-495 could reverse the promotive effects exerted by UCA1. Taken conjointly, UCA1, as a competing endogenous RNA (ceRNA) of miR-495, could accelerate the development of GC by upregulating PRL-3, highlighting a potentially promising basis for the targeted intervention treatment of GC.

Chemotherapy induced PRL3 expression promotes cancer growth via plasma membrane remodeling and specific alterations of caveolae-associated signaling

BackgroundThe outcome of cancer therapy is greatly defined by the ability of a tumor cell to evade treatment and re-establish its bulk mass after medical interventions. Consequently, there is an urgent need for the characterization of molecules affecting tumor reoccurrence. The phosphatase of regenerating liver 3 (PRL3) protein was recently emerged among the targets that could affect such a phenomenon.MethodsThe expression induction of PRL3 in melanoma cells treated with chemotherapeutic agents was assessed by western blotting. The effect of PRL3 expression on cancer growth was investigated both in vitro and in vivo. The association of PRL3 with the caveolae structures of the plasma membrane was analyzed by detergent free raft purification. The effect of PRL3 expression on the membrane organization was assayed by electron microscopy and by membrane biophysical measurements. Purification of the plasma membrane fraction and co-immunoprecipitation were used to evaluate the altered protein composition of the plasma membrane upon PRL3 expression.ResultsHere, we identified PRL3 as a genotoxic stress-induced oncogene whose expression is significantly increased by the presence of classical antitumor therapeutics. Furthermore, we successfully connected the presence of this oncogene with increased tumor growth, which implies that tumor cells can utilize PRL3 effects as a survival strategy. We further demonstrated the molecular mechanism that is connected with the pro-growth action of PRL3, which is closely associated with its localization to the caveolae-type lipid raft compartment of the plasma membrane. In our study, PRL3 was associated with distinct changes in the plasma membrane structure and in the caveolar proteome, such as the dephosphorylation of integrin β1 at Thr788/Thr789 and the increased partitioning of Rac1 to the plasma membrane. These alterations at the plasma membrane were further associated with the elevation of cyclin D1 in the nucleus.ConclusionsThis study identifies PRL3 as an oncogene upregulated in cancer cells upon exposure to anticancer therapeutics. Furthermore, this work contributes to the existing knowledge on PRL3 function by characterizing its association with the caveolae-like domains of the plasma membrane and their resident proteins.

Phosphatase of regenerating liver-3 (PRL-3) is overexpressed in classical Hodgkin lymphoma and promotes survival and migration

BackgroundPhosphatase of regenerating liver-3 (PRL-3) is implicated in oncogenesis of hematological and solid cancers. PRL-3 expression increases metastatic potential, invasiveness and is associated with poor prognosis. With this study, we aimed to show a possible oncogenic role of PRL-3 in classical Hodgkin lymphoma (cHL).MethodsPRL-3 expression was measured in 25 cHL patients by immunohistochemistry and gene expression was analyzed from microdissected malignant cells. We knocked down PRL-3 in the cHL cell lines L1236 and HDLM2 and used small molecular inhibitors against PRL-3 to investigate proliferation, migration and cytokine production.ResultsPRL-3 protein was expressed in 16% of patient samples. In three different gene expression datasets, PRL-3 was significantly overexpressed compared to normal controls. PRL-3 knockdown reduced proliferation, viability and Mcl-1 expression in L1236, but not in HDLM2 cells. Thienopyridone, a small molecule inhibitor of PRL-3, reduced proliferation of both L1236 and HDLM2. PRL-3 affected IL-13 secretion and enhanced STAT6 signaling. IL-13 stimulation partially rescued proliferation in L1236 cells after knockdown of PRL-3. PRL-3 knockdown reduced migration in both L1236 and HDLM2 cells.ConclusionPRL-3 was overexpressed in a subset of cHL patients. Inhibition of PRL-3 increased IL-13 cytokine production and reduced migration, proliferation and viability. The effects could be mediated through regulation of the anti-apoptotic molecule Mcl-1 and a feedback loop of IL-13 mediated activation of STAT6. This point to a role for PRL-3 in the pathogenesis of Hodgkin lymphoma, and PRL-3 could be a possible new drug target.

A loss-of-function genetic screening reveals synergistic targeting of AKT/mTOR and WTN/\u03b2-catenin pathways for treatment of AML with high PRL-3 phosphatase

BackgroundProtein tyrosine phosphatase of regenerating liver 3 (PRL-3) is overexpressed in a subset of AML patients with inferior prognosis, representing an attractive therapeutic target. However, due to relatively shallow pocket of the catalytic site of PRL-3, it is difficult to develop selective small molecule inhibitor.MethodsIn this study, we performed whole-genome lentiviral shRNA library screening to discover synthetic lethal target to PRL-3 in AML. We used specific small molecule inhibitors to validate the synthetic lethality in human PRL-3 high vs PRL-3 low human AML cell lines and primary bone marrow cells from AML patients. AML mouse xenograft model was used to examine the in vivo synergism.ResultsThe list of genes depleted in TF1-hPRL3 cells was particularly enriched for members involved in WNT/β-catenin pathway and AKT/mTOR signaling. These findings prompted us to explore the impact of AKT/mTOR signaling inhibition in PRL-3 high AML cells in combination with WNT/β-catenin inhibitor. VS-5584, a novel, highly selective dual PI3K/mTOR inhibitor, and ICG-001, a WNT inhibitor, were used as a combination therapy. A synthetic lethal interaction between mTOR/AKT pathway inhibition and WNT/β-catenin was validated by a variety of cellular assays. Notably, we found that treatment with these two drugs significantly reduced leukemic burden and prolonged survival of mice transplanted with human PRL-3 high AML cells, but not with PRL-3 low AML cells.ConclusionsIn summary, our results support the existence of cooperative signaling networks between AKT/mTOR and WNT/β-catenin pathways in PRL-3 high AML cells. Simultaneous inhibition of these two pathways could achieve robust clinical efficacy for this subtype of AML patient with high PRL-3 expression and warrant further clinical investigation.

Downregulating PRL-3 inhibit migration and invasion of lung cancer cell via RhoA and mDia1.

The overexpression of phosphatase of regenerating liver-3 (PRL-3) affects the migration and invasion of epithelial cells. Little is known about the substrates or pathways that PRL-3 interacts with. We studied the action and the mechanism of PRL-3 in migration and invasion of lung cancer. We detected the expression of PRL-3 in lung cancer cell lines and normal human bronchial epithelial cell. We found that PRL-3 expression was high in lung cancer cells. Knockdown of PRL-3 by siRNA inhibited cell migration and invasion and reorganizated the cytoskeleton. Furthermore, blocking PRL-3 decreased RhoA activity and mDia1 expression. Blocking RhoA or mDia1 showed the similar changes of cytoskeleton and suppression of migration and invasion as inhibiting PRL-3 expression. Blocking RhoA inhibited the expression of mDia1. These data indicate that downregulating PRL-3 inhibit cell migration and invasion by inactivating RhoA to downregulate mDia1 to reorganizate cytoskeleton of lung cancer cells.

PRL-3 is a potential glioblastoma prognostic marker and promotes glioblastoma progression by enhancing MMP7 through the ERK and JNK pathways.

Purpose: Glioblastoma is the most common and aggressive type of primary brain malignancy and is associated with a poor prognosis. Previously, we found that phosphatase of regenerating liver-3 (PRL-3) was significantly up-regulated in glioblastoma as determined by a microarray analysis. However, the function of PRL-3 in glioblastoma remains unknown. We aimed to investigate the clinical relationship between PRL-3 and glioblastoma, and uncover the mechanisms of PRL-3 in the process of glioblastoma.Methods: PRL-3 expression was evaluated in 61 glioblastoma samples and 4 cell lines by RT-qPCR and immunohistochemistry. Kaplan-Meier analysis was performed to evaluate the prognostic value of PRL-3 for overall survival (OS) and progression-free survival (PFS) for glioblastoma patients. Proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and EdU proliferation assay, migration and invasion by wound-closure/Transwell assays, and qRT-PCR/immunoblotting/IHC were used for both in vivo and in vitro investigations.Result: A high PRL-3 expression level was closely correlated with unfavorable OS and PFS for glioblastoma patients, and was also significantly correlated with Ki-67 expression. Down-regulation of PRL-3 inhibited glioma cell proliferation, invasion and migration through ERK/JNK/matrix metalloproteinase 7 (MMP7) in vitro and in vivo.Conclusions: PRL-3 expression enhances the invasion and proliferation of glioma cells, highlighting this phosphatase as a novel prognostic candidate and an attractive target for future therapy in glioblastoma.

PRL-3 promotes breast cancer progression by downregulating p14ARF-mediated p53 expression.

Prior studies have demonstrated that phosphatase of regenerating liver-3 (PRL-3) serves avital function in cell proliferation and metastasis in breast cancer. However, the molecular mechanisms underlying the function of PRL-3 in breast cancer remain unknown. PRL-3 expression was analyzed in 24 pairs of breast cancer and normal tissues using the reverse transcription-quantitative polymerase chain reaction assay. The results of the present study identified that the expression of PLR-3 in breast cancer tissues was increased 4.2-fold, compared with normal tissues. Notably, overexpression of PRL-3 significantly promoted the proliferation of cancer cells and inhibited endogenous p53 expression by downregulating the expression level of p14 alternate reading frame (p14ARF). In addition, decreased expression levels of PRL-3 resulted in decreased breast cancer cell proliferation and increased expression level of p14ARF. These results suggested that PRL-3 enhances cell proliferation by downregulating p14ARF expression, which results in decreased levels ofp53. The results of the present study demonstrated that PRL-3 promotes tumor proliferation by affecting the p14ARF-p53 axis, and that it may serve as a prognostic marker for patients with breast cancer.

PRL-3 Is Involved in Estrogen- and IL-6-Induced Migration of Endometrial Stromal Cells From Ectopic Endometrium.

To investigate the role of phosphatase of regenerating liver-3 (PRL-3) in the 17β-estradiol (E2)- and interleukin 6 (IL-6)-induced migration of endometrial stromal cells (ESCs) from ectopic endometrium. Ectopic endometrial tissues were collected from patients with endometriosis, and PRL-3 expression in ectopic and eutopic endometrium was examined by immunohistochemistry. Endometrial stromal cells isolated from ectopic endometrium were treated with E2, progesterone (P), IL-6, or sodium orthovanadate (Sov) to inhibit PRL-3. Total RNA and protein were extracted from ESCs after treatment for quantitative real-time polymerase chain reaction and Western blot analyses. Cell migration was assessed using a scratch wound assay. Phosphatase of regenerating liver 3 protein was highly expressed in the endometrial glandular cells (EGCs) and ESCs in ectopic endometrium, whereas its weak expression was observed only in EGCs in eutopic endometrium. Both E2 and IL-6 treatment significantly increased PRL-3 messenger RNA and protein expression, and P treatment significantly inhibited PRL-3 expression. However, E2-induced PRL-3 expression in ESCs from ectopic endometrium was significantly blocked by IL-6 antibody. Moreover, E2- and IL-6-enhanced cell migration was completely abrogated by Sov treatment. Furthermore, Sov treatment could significantly promote PTEN expression but inhibit E2- and IL-6-induced p-AKT activation. Phosphatase of regenerating liver 3 plays a key role in the E2- and IL-6-induced migration of ESCs from ectopic endometrium, a process that is involved in the PTEN-AKT signaling pathway.

Expression of phosphatase of regenerating liver-3 is associated with prognosis of Wilms' tumor.

ObjectiveThe current study was undertaken to explore the clinical and prognostic value of phosphatase of regenerating liver-3 (PRL-3) expression in Wilms’ tumor.MethodsSeventy-six patients with Wilms’ tumor in Qilu Hospital from January 2003 to July 2009 were enrolled in the study. Protein expression level of PRL-3 was examined by immunohistochemical staining, and the correlation between PRL-3 expression and histopathological parameters, clinical variables, and outcome of patients with Wilms’ tumor were analyzed.ResultsWe found that 19% of patients with unfavorable histology had tumor recurrence and 16% of patients died following the operation. PRL-3 was expressed in 15 out of 76 tumors (19%) and expressed highly in unfavorable histology Wilms’ tumor (P=0.04). PRL-3 protein expression level was correlated to 2.5-fold increase in recurrence rate of Wilms’ tumor (P=0.06) without any statistically significant difference. However, in favorable histology Wilms’ tumor, PRL-3 expression was correlated to an increase of 3.4-fold in recurrence rate (P=0.03).ConclusionThe expression of PRL-3 protein was correlated with an increased recurrence rate of favorable histology Wilms’ tumor. PRL-3 may serve as a promising biomarker for predicting patients with high risk of Wilms’ tumor. Further investigations are warranted to investigate the clinical function of PRL-3 in Wilms’ tumor.

Abstract 198: The phosphatase PRL-3 is expressed in primary B-ALL cells and is important for adhesion and migration

Abstract Introduction: Phosphatase of regenerating liver -3 (PRL-3) is a dual specificity phosphatase, and is associated with aggressiveness and metastatic disease in a number of solid tumors. Less is known about its role in hematological cancer, but we have previously shown that PRL-3 is expressed in primary multiple myeloma (MM) cells and MM cell lines. More recently PRL-3 is shown to be expressed in acute myeloid leukemia (AML), and associated with poor prognosis. Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Despite progress in treatment and survival, treatment related toxicity is a major concern. Therefore, it is a need for new clinical markers and therapy targets to optimize the treatment. We hypothesized that PRL-3 is expressed, and have oncogenic functions in B-ALL, and can be a possible clinical marker and a novel drug target. Methods: Primary ALL cells from peripheral blood were obtained from The Regional Biobank of Central Norway, and PRL-3 mRNA expression was measured with qRT-PCR. The PreB-ALL cell lines Reh and MHH-CALL-4 were used for further experiments. IL-7 (100 ng/mL) were used for stimulation. ShRNA against PRL-3 was used to knock down PRL-3 in Reh (shPRL-3) and for empty vector control (shMOCK) by use of lentiviral transduction. To study adhesion we used fibronectin (20 μg/mL) and stimulated with IL-7, IL-8 and IGF-1 (all 100 ng/mL) for 45 min in 37°C. Migration was studied with transwell permeable plates (pore size 3 μm) using SDF1α (75 ng/mL) as a chemoattractant. Further we examined the effect of the small molecular inhibitor PRL-3 Inhibitor I on ALL cell lines. Apoptosis and cell viability was determined by Annexin-FITC/-PI with flow cytometry, and by CellTiter-Glo® Luminescent Cell Viability assay kit, after 24-72 hours incubation with PRL-3 Inhibitor I. Results: 89% (16 of 18) of primary B-ALL samples expressed PRL-3, and 33% (6 of 18) at high levels. Stimulation with IL-7 induced expression of PRL-3 in a dose-dependent manner in Reh and MHH-CALL-4. The knock down of PRL-3 by shRNA was 80% efficient. Reh shMOCK cells were significantly more adherent to fibronectin after stimulation with IL-7, IL-8 and IGF-1 compared to Reh shPRL3. The cells’ ability to migrate towards a SDF1α gradient were significantly reduced in Reh shPRL-3 cells compared with Reh shMOCK. PRL-3 inhibitor I also reduced the viability and induced apoptosis in Reh cell line in a dose-dependent manner, but not in MHH-CALL-4 cell line, at a concentration of 40-80 μM. Conclusion: PRL-3 was expressed in 89% of primary B-ALL samples. Knock down of PRL-3 clearly reduced cell adhesion and migration. PRL-3 inhibitor I induced apoptosis and reduced cell viability in Reh, but not in MHH-CALL-4. This study indicates that PRL-3 could be important in the pathogenesis of B-ALL, and might be a suitable target for treatment in the future. Citation Format: Magnus Aassved A. Hjort, Pegah Abdollahi, Esten Vandsemb, Tobias Schmidt Slørdahl, Bendik Lund, Magne Børset, Torstein Baade Rø. The phosphatase PRL-3 is expressed in primary B-ALL cells and is important for adhesion and migration. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 198.

The clinical significance of PRL-3,VEGF expression in sinonasalsquamous cell carcinoma

Objective:To analyze the clinical significance of phosphatase of regenerating liver-3(PRL-3) and vascular endothelial growth factor(VEGF)expression in sinonasal squamous cell carcinomas.Method:We use immunohistochemical analysis and RT-PCR to detecte the expression of PRL-3 and VEGF protein in 62 cases of sinonasal squamous carcinoma tissues(SNSCC),30 cases of nasal polyps(NP),and 25 cases of normal nasal mucosa(NM).Result:①The expression of PRL-3 and VEGF in sinonasal squamous cell carcinoma tissues were statistically higher than in nasal polyps and normal nasal mucosa tissues (P<0.05).②The expression of PRL-3 and VEGF were not correlated with patient's age or gender(P>0.05).But the High expression of PRL-3 and VEGF in SNSCC was significantly related with advanced,lower tumor differentiation and lymph node metastasis(P<0.05).③The expression of PRL-3 and VEGF was positively correlated in sinonasal squamous cell carcinomas.Conclusion:The expression of PRL-3 and VEGF in SNSCC may involve in the regulation of tumor growth and differentiation.The expressing intensity may reflect the proliferation activity of sinonasal squamous cell carcinoma cell.PRL-3 and VEGF may promote the tumor metastasis in a synergistic manner.

The phosphatase of regenerating liver-3 (PRL-3) is important for IL-6-mediated survival of myeloma cells.

Multiple myeloma (MM) is a neoplastic proliferation of bone marrow plasma cells. PRL-3 is a phosphatase induced by interleukin (IL)-6 and other growth factors in MM cells and promotes MM-cell migration. PRL-3 has also been identified as a marker gene for a subgroup of patients with MM. In this study we found that forced expression of PRL-3 in the MM cell line INA-6 led to increased survival of cells that were depleted of IL-6. It also caused redistribution of cells in cell cycle, with an increased number of cells in G2M-phase. Furthermore, forced PRL-3 expression significantly increased phosphorylation of Signal transducer and activator of transcription (STAT) 3 both in the presence and the absence of IL-6. Knockdown of PRL-3 with shRNA reduced survival in MM cell line INA-6. A pharmacological inhibitor of PRL-3 reduced survival in the MM cell lines INA-6, ANBL-6, IH-1, OH-2 and RPMI8226. The inhibitor also reduced survival in 9 of 9 consecutive samples of purified primary myeloma cells. Treatment with the inhibitor down-regulated the anti-apoptotic protein Mcl-1 and led to activation of the intrinsic apoptotic pathway. Inhibition of PRL-3 also reduced IL-6-induced phosphorylation of STAT3. In conclusion, our study shows that PRL-3 is an important mediator of growth factor signaling in MM cells and hence possibly a good target for treatment of MM.

Phosphatase of regenerating liver 3 (PRL-3) is overexpressed in human prostate cancer tissue and promotes growth and migration.

BackgroundPRL-3 is a phosphatase implicated in oncogenesis in multiple cancers. In some cancers, notably carcinomas, PRL-3 is also associated with inferior prognosis and increased metastatic potential. In this study we investigated the expression of PRL-3 mRNA in fresh-frozen samples from patients undergoing radical prostatectomy because of prostate cancer (PC) and the biological function of PRL-3 in prostate cancer cells.MethodsSamples from 41 radical prostatectomy specimens (168 samples in total) divided into low (Gleason score ≤ 6), intermediate (Gleason score = 7) and high (Gleason score ≥ 8) risk were analyzed with gene expression profiling and compared to normal prostate tissue. PRL-3 was identified as a gene with differential expression between healthy and cancerous tissue in these analyses. We used the prostate cancer cell lines PC3 and DU145 and a small molecular inhibitor of PRL-3 to investigate whether PRL-3 had a functional role in cancer. Relative ATP-measurement and thymidine incorporation were used to assess the effect of PRL-3 on growth of the cancer cells. We performed an in vitro scratch assay to investigate the involvement of PRL-3 in migration. Immunohistochemistry was used to identify PRL-3 protein in prostate cancer primary tumor and corresponding lymph node metastases.ResultsCompared to normal prostate tissue, the prostate cancer tissue expressed a significantly higher level of PRL-3. We found PRL-3 to be present in both PC3 and DU145, and that inhibition of PRL-3 led to growth arrest and apoptosis in these two cell lines. Inhibition of PRL-3 led to reduced migration of the PC3 cells. Immunohistochemistry showed PRL-3 expression in both primary tumor and corresponding lymph node metastases.ConclusionsPRL-3 mRNA was expressed to a greater extent in prostate cancer tissue compared to normal prostate tissue. PRL-3 protein was expressed in both prostate cancer primary tumor and corresponding lymph node metastases. The results from our in vitro assays suggest that PRL-3 promotes growth and migration in prostate cancer. In conclusion, these results imply that PRL-3 has a role in the pathogenesis of prostate cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0830-z) contains supplementary material, which is available to authorized users.

Phosphatase of regenerating liver-3 inhibits invasiveness and proliferation in non-small cell lung cancer by regulating the epithelial-mesenchymal transition.

Phosphatase of regenerating liver-3 (PRL-3) has been reported to be associated with colon and gastric cancer metastasis. However, the role and function of PRL-3 in human non-small cell lung cancer cells is unknown. Our studies showed that the expression of PRL-3mRNA and protein are higher in less invasive human lung adenocarcinoma cells than in highly invasive cell lines. Ectopic expression of PRL-3 reduced cell capacity for anchorage-dependent growth, anchorage-independent growth, migration, and invasion in vitro, as well as tumorigenesis in vivo. Conversely, catalytic (C104S) and prenylation-site (C170S) mutants enhanced cell invasion. Microarray profiling of PRL-3 transfectants revealed the pathways potentially involving PRL-3, including the epithelial-mesenchymal transition (EMT), extracellular matrix remodeling, and the WNT signaling pathway. Furthermore, we demonstrated that increased PRL-3 reduced Slug and enhanced E-cadherin gene expression through the AKT/GSK3β/β-catenin pathway. In conclusion, our data suggest that PRL-3 might play a tumor suppressor role in lung cancer, distinct from other cancers, by inhibiting EMT-related pathways.

Elevated phosphatase of regenerating liver 3 (PRL-3) promotes cytoskeleton reorganization, cell migration and invasion in endometrial stromal cells from endometrioma

Is phosphatase of regenerating liver-3 (PRL-3) associated with increased motility of endometriotic cells from endometrioma? Elevated PRL-3 promotes cytoskeleton reorganization, cell migration and invasion of endometrial stromal cells (ESCs) from endometrioma. Overexpression of PRL-3 is associated with cancer cell migration, invasion and metastatic phenotype. Primary human ESCs were isolated from eutopic endometrium of women without endometriosis (EuCo, n = 10), with histologically proven endometrioma (EuEM, n = 19) and from the cyst wall of ovarian endometriosis (OvEM, n = 26). The expression of PRL-3 in ESCs derived from EuCo, EuEM and OvEM at different phases of menstrual cycle were compared. The protein and mRNA levels of PRL-3 were examined by western blot and RT-qPCR, respectively. ESCs from OvEM were transfected with/without short hairpin RNA (shRNA) or small interfering RNA (siRNA). Additionally, a plasmid-mediated delivery system was used to achieve PRL-3 overexpression in ESCs from EuEM. The cellular distribution of F-actin and α-tubulin were examined by immunocytochemistry. Cell motility was evaluated by a transwell migration/invasion assay. The protein and mRNA levels of PRL-3 are significantly elevated in ESCs from OvEM compared with EuCo and EuEM. The expression of PRL-3 was not altered between proliferative phase and secretory phase in ESCs from all groups. Knockdown of PRL-3 significantly modified the distribution of F-actin and α-tubulin cytoskeleton, inhibited cell migration and invasion. Endogenous inhibition of PRL-3 attenuated the expression of Ras homolog gene family members A and C (RhoA, RhoC), Rho-associated coiled-coil-containing protein kinase 1 (ROCK1) and matrix metalloproteinase (MMP) 9, but not MMP2 in ESCs from OvEM. Additionally, overexpression of PRL-3 in ESCs from EuEM up-regulates cell migration and invasion, and increases the expression of RhoA, RhoC, ROCK1 and MMP9. Lack of in vivo animal studies is the major limitation of our report. Our results should be further confirmed in a larger cohort of patients and extended to include eutopic and ectopic endometrium from patients with peritoneal endometriosis at different stages of the disease. Our study describes that elevated expression of PRL-3 contributes to the cell motility of ESCs from endometrioma. The results emphasize the importance of metastatic-related factor PRL-3 in the pathogenesis of endometrioma. This work was supported by National Natural Science Foundation of China (No. 81170546) and Zhejiang Medicine Science and Technology Projects (No. Y13H040003). The authors declare no conflict of interest.