scholarly journals Pituitary Somatotroph Adenoma Cell-Derived Exosomes: Characterization of Novel Non-Hormonal Functions

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A652-A653
Author(s):  
Cuiqi Zhou ◽  
Stephen Shen ◽  
Rosemary Moran ◽  
Shlomo Melmed

Abstract Exosomes, small extracellular vesicles carrying lipids, proteins, DNA and RNA, enable intercellular communication. Pituitary-derived exosomes have not been well validated, and as no human pituitary cell lines are available, we characterized exosomes derived from rat somatotroph tumor cells (GH1 and GH3). Rat FR and H9C2 cells were used as non-pituitary controls. Exosomes were isolated from serum-free culture supernatants by combining ultrafiltration and ultracentrifugation to eliminate hormone contamination. Derived exosomes were analyzed by NanoSight to visualize, size, and count particles. Exosomal proteins were extracted and exosome markers including TSG101, ALIX, CD63, HSP70, HSP90 detected by Western Blot. The exosome inhibitor GW4869 (10 µM, 30 h) reduced exosome release (up to 81%), whereas treating cells with hydrocortisone (0.1 µM, 72 h) increased exosome production (up to 42%) in GH1 and GH3 cells. Exosomal shuttle RNA characterized by RNA-Seq showed distinct pituitary vs non-pituitary exosome RNA profiles. Selected miRNAs assessed in exosomes and corresponding cells by qRT-PCR validated exosomal RNA-seq and suggested that miRNA signatures in exosomes and in respective cells of origin were concordant. Next, we explored downstream signaling of GH1-derived exosomes (GH1-exo) in vitro and in vivo and studied biological actions in normal hepatocytes and in malignant cells. As evidenced by mRNA-seq, GH1-exo distinctly altered signaling pathways in rat primary hepatocytes, vs pathways elicited by GH or PRL (0.5 µg/mL, 24 h). GH1-exo, FR-exo or vehicle were intravenously injected to 4-week-old female Wistar rats twice weekly for 4 weeks (5*109 exo/200 g, n=3), and livers dissected for mRNA-seq. Among GH1-exo specifically regulated genes, EIF2AK/ATF4, involved in cAMP responses and amino acid biosynthesis, were attenuated. In hepatocytes, GH1-exo suppressed up to 65% of nascent protein synthesis and reduced forskolin (10 µM)-stimulated cAMP activity by 19%, while GH (0.01-1 µg/mL) did not affect this pathway. Notably, GH1-exo also attenuated malignant cell motility. Both GH1-exo incubation or GH1 cell co-culture (48 h) suppressed migration, invasion and wound healing of HCT116 cancer cells by up to 70%. In contrast, treatment with rGH (0.5 µg/mL) increased HCT116 motility. Intravenous administration of GH1-exo (1010 exo/mouse, twice a week for 5 weeks) decreased metastatic tumor volume by 40% in nude mice harboring splenic HCT116 implants (5*105 cells/mouse, n=10), and especially abrogated hepatic metastases. mRNA-seq of GH1-exo treated HCT116 cells vs controls indicated dysregulated p53 and MAPK pathways, which may partially explain mechanisms underlying motility attenuation. The results elucidate novel biological actions of somatotroph adenoma cell-derived exosomes and suggest exosomes as non-hormonal messengers produced by pituitary tumors.

Author(s):  
Cuiqi Zhou ◽  
Stephen Shen ◽  
Rosemary Moran ◽  
Nan Deng ◽  
Eduardo Marbán ◽  
...  

Abstract Context The identification and biological actions of pituitary-derived exosomes remain elusive. Objective This work aimed to validate production of exosomes derived from human and rat pituitary and elucidate their actions. Methods Isolated extracellular vesicles (EVs) were analyzed by Nanoparticle Tracking Analysis (NTA) and expressed exosomal markers detected by Western blot, using nonpituitary fibroblast FR and myoblast H9C2 cells as controls. Exosome inhibitor GW4869 was employed to detect attenuated EV release. Exosomal RNA contents were characterized by RNA sequencing. In vitro and in vivo hepatocyte signaling alterations responding to GH1-derived exosomes (GH1-exo) were delineated by mRNA sequencing. GH1-exo actions on protein synthesis, cAMP (3′,5′-cyclic adenosine 5′-monophosphate) response, cell motility, and metastases were assessed. Results NTA, exosomal marker detection, and GW4869 attenuated EV release, confirming the exosomal identity of pituitary EVs. Hydrocortisone increased exosome secretion in GH1 and GH3 cells, suggesting a stress-associated response. Exosomal RNA contents showed profiles distinct for pituitary cells, and rat primary hepatocytes exposed to GH1-exo exhibited transcriptomic alterations distinct from those elicited by growth hormone or prolactin. Intravenous GH1-exo injection into rats attenuated hepatic Eif2ak2 and Atf4 mRNA expression, both involved in cAMP responses and amino acid biosynthesis. GH1-exo suppressed protein synthesis and forskolin-induced cAMP levels in hepatocytes. GH1-exo–treated HCT116 cells showed dysregulated p53 and mitogen-activated protein kinase (MAPK) pathways and attenuated motility of malignant HCT116 cells, and decreased tumor metastases in nude mice harboring splenic HCT116 implants. Conclusion Our findings elucidate biological actions of somatotroph-derived exosomes and implicate exosomes as nonhormonal pituitary-derived messengers.


2019 ◽  
Vol 26 (1) ◽  
pp. 13-29 ◽  
Author(s):  
Lautaro Zubeldía-Brenner ◽  
Catalina De Winne ◽  
Sofía Perrone ◽  
Santiago A Rodríguez-Seguí ◽  
Christophe Willems ◽  
...  

Preclinical and clinical studies support that Notch signaling may play an important oncogenic role in cancer, but there is scarce information for pituitary tumors. We therefore undertook a functional study to evaluate Notch participation in pituitary adenoma growth. Tumors generated in Nude mice by subcutaneous GH3 somatolactotrope cell injection were treated in vivo with DAPT, a γ-secretase inhibitor, thus inactivating Notch signaling. This treatment led to pituitary tumor reduction, lower prolactin and GH tumor content and a decrease in angiogenesis. Furthermore, in silico transcriptomic and epigenomic analyses uncovered several tumor suppressor genes related to Notch signaling in pituitary tissue, namely Btg2, Nr4a1, Men1, Zfp36 and Cnot1. Gene evaluation suggested that Btg2, Nr4a1 and Cnot1 may be possible players in GH3 xenograft growth. Btg2 mRNA expression was lower in GH3 tumors compared to the parental line, and DAPT increased its expression levels in the tumor in parallel with the inhibition of its volume. Cnot1 mRNA levels were also increased in the pituitary xenografts by DAPT treatment. And the Nr4a1 gene was lower in tumors compared to the parental line, though not modified by DAPT. Finally, because DAPT in vivo may also be acting on tumor microenvironment, we determined the direct effect of DAPT on GH3 cells in vitro. We found that DAPT decreases the proliferative, secretory and migration potential of GH3 cells. These results position selective interruption of Notch signaling as a potential therapeutic tool in adjuvant treatments for aggressive or resistant pituitary tumors.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3470
Author(s):  
Aubrey L. Miller ◽  
Patrick L. Garcia ◽  
Samuel C. Fehling ◽  
Tracy L. Gamblin ◽  
Rebecca B. Vance ◽  
...  

Gemcitabine is used to treat pancreatic cancer (PC), but is not curative. We sought to determine whether gemcitabine + a BET bromodomain inhibitor was superior to gemcitabine, and identify proteins that may contribute to the efficacy of this combination. This study was based on observations that cell cycle dysregulation and DNA damage augment the efficacy of gemcitabine. BET inhibitors arrest cells in G1 and allow increases in DNA damage, likely due to inhibition of expression of DNA repair proteins Ku80 and RAD51. BET inhibitors (JQ1 or I-BET762) + gemcitabine were synergistic in vitro, in Panc1, MiaPaCa2 and Su86 PC cell lines. JQ1 + gemcitabine was more effective in vivo than either drug alone in patient-derived xenograft models (P < 0.01). Increases in the apoptosis marker cleaved caspase 3 and DNA damage marker γH2AX paralleled antitumor efficacy. Notably, RNA-seq data showed that JQ1 + gemcitabine selectively inhibited HMGCS2 and APOC1 ~6-fold, compared to controls. These proteins contribute to cholesterol biosynthesis and lipid metabolism, and their overexpression supports tumor cell proliferation. IPA data indicated that JQ1 + gemcitabine selectively inhibited the LXR/RXR activation pathway, suggesting the hypothesis that this inhibition may contribute to the observed in vivo efficacy of JQ1 + gemcitabine.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii414-iii414
Author(s):  
Muh-Lii Liang ◽  
Tsung-Han Hsieh ◽  
Tai-Tong Wong

Abstract BACKGROUND Glial-lineage tumors constitute a heterogeneous group of neoplasms, comprising gliomas, oligodendrogliomas, and ependymomas, which account for 40%–50% of all pediatric central nervous system tumors. Advances in modern neuro-oncological therapeutics are aimed at improving neoadjuvant chemotherapy and deferring radiotherapy because radiation exposure may cause long-term side effects on the developing brain in young children. Despite aggressive treatment, more than half the high-grade gliomas (pHGGs) and one-third of ependymomas exhibit recurrence within 2 years of initial treatment. METHODS By using integrated bioinformatics and through experimental validation, we found that at least one gene among CCND1, CDK4, and CDK6 was overexpressed in pHGGs and ependymomas. RESULTS The use of abemaciclib, a highly selective CDK4/6 inhibitor, effectively inhibited cell proliferation and reduced the expression of cell cycle–related and DNA repair–related gene expression, which was determined through RNA-seq analysis. The efficiency of abemaciclib was validated in vitro in pHGGs and ependymoma cells and in vivo by using subcutaneously implanted ependymoma cells from patient-derived xenograft (PDX) in mouse models. Abemaciclib demonstrated the suppression of RB phosphorylation, downstream target genes of E2F, G2M checkpoint, and DNA repair, resulting in tumor suppression. CONCLUSION Abemaciclib showed encouraging results in preclinical pediatric glial-lineage tumors models and represented a potential therapeutic strategy for treating challenging tumors in children.


2021 ◽  
Vol 22 (3) ◽  
pp. 1407
Author(s):  
Hongxia Liu ◽  
Wang Zheng ◽  
Qianping Chen ◽  
Yuchuan Zhou ◽  
Yan Pan ◽  
...  

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors and is majorly treated by radiotherapy. However, radiation resistance remains a serious obstacle to the successful treatment of NPC. The aim of this study was to discover the underlying mechanism of radioresistance and to elucidate novel genes that may play important roles in the regulation of NPC radiosensitivity. By using RNA-seq analysis of NPC cell line CNE2 and its radioresistant cell line CNE2R, lncRNA CASC19 was screened out as a candidate radioresistance marker. Both in vitro and in vivo data demonstrated that a high expression level of CASC19 was positively correlated with the radioresistance of NPC, and the radiosensitivity of NPC cells was considerably enhanced by knockdown of CASC19. The incidence of autophagy was enhanced in CNE2R in comparison with CNE2 and another NPC cell line HONE1, and silencing autophagy with LC3 siRNA (siLC3) sensitized NPC cells to irradiation. Furthermore, CASC19 siRNA (siCASC19) suppressed cellular autophagy by inhibiting the AMPK/mTOR pathway and promoted apoptosis through the PARP1 pathway. Our results revealed for the first time that lncRNA CASC19 contributed to the radioresistance of NPC by regulating autophagy. In significance, CASC19 might be a potential molecular biomarker and a new therapeutic target in NPC.


Endocrinology ◽  
2012 ◽  
Vol 153 (7) ◽  
pp. 2963-2973 ◽  
Author(s):  
Mei Xu ◽  
Aaron J. Knox ◽  
Katherine A. Michaelis ◽  
Katja Kiseljak-Vassiliades ◽  
Bette K. Kleinschmidt-DeMasters ◽  
...  

Reprimo (RPRM), initially identified as a downstream effector of p53-induced cell cycle arrest at G2/M, is a putative tumor suppressor silenced in some types of cancer. In microarrays, the RPRM transcript was repressed 26-fold in gonadotrope (null cell) human pituitary tumors compared with normal pituitary but in the absence of changes in p53. Inhibition of RPRM mRNA was confirmed by RT-PCR in all gonadotrope tumors, most GH samples, and variably in other tumor types. Human pituitary tumors showed no evidence of abnormal promoter hypermethylation as a mechanism of RPRM repression. RPRM stable expression in gonadotrope (LβT2) and GH (GH3) pituitary cells resulted in decreased rates of cell proliferation by 55 and 30%, respectively; however, RPRM reexpression did not alter G2/M transition. In addition, RPRM increased rates of apoptosis in response to growth factor deprivation as assessed by caspase-3 cleavage and nuclear condensation. Clonagenic assays showed a 5.3- and 3.7-fold suppression of colony growth in RPRM-overexpressing LβT2 and GH3 cells, respectively, supporting its role as a tumor suppressor. In cells stably expressing RPRM mRNA, protein levels were actively suppressed due to rapid degradation through ubiquitination and proteasomal targeting. Growth factor withdrawal, as a model of cellular stress, stabilized RPRM protein levels. Together these data suggest that RPRM is transiently up-regulated at a posttranscriptional level in times of cellular stress to restrict cell survival, proliferation, and tumor formation. When RPRM is silenced as in human pituitary tumors, unrestrained growth and tumor progression may occur.


2018 ◽  
Author(s):  
Avi Z. Rosenberg ◽  
Carrie Wright ◽  
Karen Fox-Talbot ◽  
Anandita Rajpurohit ◽  
Courtney Williams ◽  
...  

AbstractAccurate, RNA-seq based, microRNA (miRNA) expression estimates from primary cells have recently been described. However, this in vitro data is mainly obtained from cell culture, which is known to alter cell maturity/differentiation status, significantly changing miRNA levels. What is needed is a robust method to obtain in vivo miRNA expression values directly from cells. We introduce expression microdissection miRNA small RNA sequencing (xMD-miRNA-seq), a method to isolate cells directly from formalin fixed paraffin-embedded (FFPE) tissues. xMD-miRNA-seq is a low-cost, high-throughput, immunohistochemistry-based method to capture any cell type of interest. As a proof-of-concept, we isolated colon epithelial cells from two specimens and performed low-input small RNA-seq. We generated up to 600,000 miRNA reads from the samples. Isolated epithelial cells, had abundant epithelial-enriched miRNA expression (miR-192; miR-194; miR-200b; miR-200c; miR-215; miR-375) and overall similar miRNA expression patterns to other epithelial cell populations (colonic enteroids and flow-isolated colon epithelium). xMD-derived epithelial cells were generally not contaminated by other adjacent cells of the colon as noted by t-SNE analysis. xMD-miRNA-seq allows for simple, economical, and efficient identification of cell-specific miRNA expression estimates. Further development will enhance rapid identification of cell-specific miRNA expression estimates in health and disease for nearly any cell type using archival FFPE material.


2019 ◽  
Author(s):  
Ugur M. Ayturk ◽  
Joseph P. Scollan ◽  
Alexander Vesprey ◽  
Christina M. Jacobsen ◽  
Paola Divieti Pajevic ◽  
...  

ABSTRACTSingle cell RNA-seq (scRNA-seq) is emerging as a powerful technology to examine transcriptomes of individual cells. We determined whether scRNA-seq could be used to detect the effect of environmental and pharmacologic perturbations on osteoblasts. We began with a commonly used in vitro system in which freshly isolated neonatal mouse calvarial cells are expanded and induced to produce a mineralized matrix. We used scRNA-seq to compare the relative cell type abundances and the transcriptomes of freshly isolated cells to those that had been cultured for 12 days in vitro. We observed that the percentage of macrophage-like cells increased from 6% in freshly isolated calvarial cells to 34% in cultured cells. We also found that Bglap transcripts were abundant in freshly isolated osteoblasts but nearly undetectable in the cultured calvarial cells. Thus, scRNA-seq revealed significant differences between heterogeneity of cells in vivo and in vitro. We next performed scRNA-seq on freshly recovered long bone endocortical cells from mice that received either vehicle or Sclerostin-neutralizing antibody for 1 week. Bone anabolism-associated transcripts were also not significantly increased in immature and mature osteoblasts recovered from Sclerostin-neutralizing antibody treated mice; this is likely a consequence of being underpowered to detect modest changes in gene expression, since only 7% of the sequenced endocortical cells were osteoblasts, and a limited portion of their transcriptomes were sampled. We conclude that scRNA-seq can detect changes in cell abundance, identity, and gene expression in skeletally derived cells. In order to detect modest changes in osteoblast gene expression at the single cell level in the appendicular skeleton, larger numbers of osteoblasts from endocortical bone are required.


2021 ◽  
Author(s):  
Yinghui Song ◽  
Zhihua Zhang ◽  
Qin Chai ◽  
GuoYi Xia ◽  
Zhangtao Yu ◽  
...  

Abstract Intrahepatic cholangiocarcinoma (ICC) is a rare high-fatal hepatobiliary malignancy, the treatment option of ICC is very limited, and the prognosis is also poor. Recently, emerging evidence has shown the potential of quercetin (QE) for cancer therapy. We explored the effect and mechanism of QE on ICC in vitro and in vivo. CCK-8 assay and Clonogenic assay showed that QE could inhibit ICC cells proliferation and survival. PI staining suggested QE could induce ICC cells arrest in G1 phase. AV/PI staining suggested QE could promote ICC cells apoptosis. Wound Healing Assay and Transwell chamber experiment suggested QE could inhibit ICC cells EMT. RNA-seq, the changes in the structure of mitochondria by electron microscopy and the key markers of ferroptosis (free iron ions, MDA, SOD, GPX4) were supported QE could promote ferroptosis in ICC cells. Molecular docking showed that QE had direct interaction with NF-κB and GPX4. In vivo, treatment with QE inhibited tumor growth and prolonged survival time of tumor-bearing nude mice. Our data for the first time suggest that QE is a new ferroptosis inducer and combinative treatment of inhibiting NF-κB in ICC cells by inducing ferroptosis and inhibiting EMT, which will hopefully provide a prospective strategy for ICC patients.


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