scholarly journals Upregulation of KLK8 Predicts Poor Prognosis in Pancreatic Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Qing Hua ◽  
Tianjiao Li ◽  
Yixuan Liu ◽  
Xuefang Shen ◽  
Xiaoyan Zhu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Progression ◽  
Poor Prognosis ◽  
Culture Media ◽  
Disease Free Survival ◽  
Mtor Pathway ◽  
Gene Set Enrichment Analysis ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) is a growing cause of cancer-related mortality worldwide. Kallikrein-related peptidase 8 (KLK8) has potential clinical values in many cancers. However, the clinicopathological significances of KLK8 in PDAC remain unknown. We explored the relationship of KLK8 to clinicopathological features of PDAC based on public databases. KLK8 expression was examined in human PDAC tissues. Cell proliferation and apoptosis were evaluated in KLK8-overexpressed human pancreatic cancer cell lines Mia-paca-2 and Panc-1. The related signaling pathways of KLK8 involved in pancreatic cancer progression were analyzed by gene set enrichment analysis (GSEA) and further verified in in vitro studies. We found that KLK8 was up-regulated in tumor tissues in the TCGA-PAAD cohort, and was an independent prognostic factor for both overall survival and disease-free survival of PDAC. KLK8 mRNA and protein expressions were increased in PDAC tissues compared with para-cancerous pancreas. KLK8 overexpression exerted pro-proliferation and anti-apoptotic functions in Mia-paca-2 and Panc-1 cells. GSEA analysis showed that KLK8 was positively associated with PI3K-Akt-mTOR and Notch pathways. KLK8-induced pro-proliferation and anti-apoptotic effects in Mia-paca-2 and Panc-1 cells were attenuated by inhibitors for PI3K, Akt, and mTOR, but not by inhibitor for Notch. Furthermore, overexpression of KLK8 in Mia-paca-2 and Panc-1 cells significantly increased epidermal growth factor (EGF) levels in the culture media. EGF receptor (EGFR) inhibitor could block KLK8-induced activation of PI3K/Akt/mTOR pathway and attenuate pro-proliferation and anti-apoptotic of KLK8 in Mia-paca-2 and Panc-1 cells. In conclusion, KLK8 overexpression exerts pro-proliferation and anti-apoptotic functions in pancreatic cancer cells via EGF signaling-dependent activation of PI3K/Akt/mTOR pathway. Upregulated KLK8 in PDAC predicts poor prognosis and may be a potential therapeutic target for PDAC.

scholarly journals Upregulation of KLK8 Predicts Poor Prognosis in Pancreatic Cancer

2020 ◽  
Author(s):  
Qing Hua ◽  
Tianjiao Li ◽  
Yixuan Liu ◽  
Xuefang Shen ◽  
Xiaoyan Zhu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Progression ◽  
Poor Prognosis ◽  
Disease Free Survival ◽  
Enrichment Analysis ◽  
Gene Set Enrichment Analysis ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is a growing cause of cancer-related mortality worldwide. Kallikrein-related peptidase 8 (KLK8) has potential clinical values in many cancers. However, the clinicopathological significances of KLK8 in PDAC remain unknown. Methods: The relationship of KLK8 to clinicopathological features of PDAC was investigated based on public databases. KLK8 expression was examined in human PDAC tissues. Cell proliferation and apoptosis were evaluated in KLK8-overexpressed human pancreatic cancer cell lines Mia-paca-2 and Panc-1. The related signaling pathways of KLK8 involved in pancreatic cancer progression were analyzed by gene set enrichment analysis (GSEA) and further verified in in vitro studies. Results: KLK8 was up-regulated in tumor tissues in the TCGA-PAAD cohort, and was an independent prognostic factor for both overall survival and disease-free survival of PDAC. KLK8 mRNA and protein expressions were increased in PDAC tissues compared with para-cancerous pancreas. KLK8 overexpression exerted pro-proliferation and anti-apoptotic functions in Mia-paca-2 and Panc-1 cells. GSEA analysis showed that KLK8 was positively associated with PI3K-Akt-mTOR and Notch pathways. KLK8-induced pro-proliferation and anti-apoptotic effects in Mia-paca-2 and Panc-1 cells were attenuated by inhibitors for PI3K, Akt, and mTOR, but not by inhibitor for Notch.Conclusion: KLK8 overexpression exerts pro-proliferation and anti-apoptotic functions in pancreatic cancer cells via PI3K/Akt/mTOR pathway. Upregulated KLK8 in PDAC predicts poor prognosis and may be a potential therapeutic target for PDAC.

scholarly journals DDR1-INDUCED NEUTROPHIL EXTRACELLULAR TRAPS DRIVE PANCREATIC CANCER METASTASIS

2020 ◽  
Author(s):  
Jenying Deng ◽  
Yaan Kang ◽  
Chien-Chia Cheng ◽  
Xinqun Li ◽  
Bingbing Dai ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Cancer Progression ◽  
Cancer Metastasis ◽  
Neutrophil Extracellular Traps ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Extracellular Traps ◽  
Pancreatic Cancer Cells

AbstractPancreatic ductal adenocarcinoma (PDAC) tumors are characterized by a desmoplastic reaction and dense collagen that is known to promote cancer progression. A central mediator of pro-tumorigenic collagen signaling is the receptor tyrosine kinase discoid domain receptor 1 (DDR1). DDR1 is a critical driver of a mesenchymal and invasive cancer cell PDAC phenotype. Previous studies have demonstrated that genetic or pharmacologic inhibition of DDR1 prevents PDAC tumorigenesis and metastasis. Here, we investigated whether DDR1 signaling has cancer cell non-autonomous effects that promote PDAC progression and metastasis. We demonstrate that collagen-induced DDR1 activation in cancer cells is a major stimulus for CXCL5 production, resulting in the recruitment of tumor-associated neutrophils (TANs), the formation of neutrophil extracellular traps (NETs) and subsequent cancer cell invasion and metastasis. Moreover, we have identified that collagen-induced CXCL5 production was mediated by a DDR1-PKCθ-SYK-NFκB signaling cascade. Together, these results highlight the critical contribution of collagen I-DDR1 interaction in the formation of an immune microenvironment that promotes PDAC metastasis.SummaryDeng et al find that collagen signaling via DDR1 on human pancreatic cancer cells drives production and release of the cytokine, CXCL5, into systemic circulation. CXCL5 then triggers infiltration of neutrophils into the tumor where they promote cancer cell progression.

scholarly journals HGF/c-Met Inhibition as Adjuvant Therapy Improves Outcomes in an Orthotopic Mouse Model of Pancreatic Cancer

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2763
Author(s):  
Tony C. Y. Pang ◽  
Zhihong Xu ◽  
Alpha Raj Mekapogu ◽  
Srinivasa Pothula ◽  
Therese Becker ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Progression ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Primary Tumour ◽  
Human Pancreatic Cancer ◽  
Pancreatic Stellate Cell ◽  
Orthotopic Mouse Model ◽  
Pancreatic Cancer Cells ◽  
Angiogenic Effect

Background: Inhibition of hepatocyte growth factor (HGF)/c-MET pathway, a major mediator of pancreatic stellate cell (PSC)−PC cell interactions, retards local and distant cancer progression. This study examines the use of this treatment in preventing PC progression after resection. We further investigate the postulated existence of circulating PSCs (cPSCs) as a mediator of metastatic PC. Methods: Two orthotopic PC mouse models, produced by implantation of a mixture of luciferase-tagged human pancreatic cancer cells (AsPC-1), and human PSCs were used. Model 1 mice underwent distal pancreatectomy 3-weeks post-implantation (n = 62). One-week post-resection, mice were randomised to four treatments of 8 weeks: (i) IgG, (ii) gemcitabine (G), (iii) HGF/c-MET inhibition (HiCi) and (iv) HiCi + G. Tumour burden was assessed longitudinally by bioluminescence. Circulating tumour cells and cPSCs were enriched by filtration. Tumours of Model 2 mice progressed for 8 weeks prior to the collection of primary tumour, metastases and blood for single-cell RNA-sequencing (scRNA-seq). Results: HiCi treatments: (1) reduced both the risk and rate of disease progression after resection; (2) demonstrated an anti-angiogenic effect on immunohistochemistry; (3) reduced cPSC counts. cPSCs were identified using immunocytochemistry (α-smooth muscle actin+, pan-cytokeratin−, CD45−), and by specific PSC markers. scRNA-seq confirmed the existence of cPSCs and identified potential genes associated with development into cPSCs. Conclusions: This study is the first to demonstrate the efficacy of adjuvant HGF/c-Met inhibition for PC and provides the first confirmation of the existence of circulating PSCs.

scholarly journals NR5A2 transcriptional activation by BRD4 promotes pancreatic cancer progression by upregulating GDF15

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Feng Guo ◽  
Yingke Zhou ◽  
Hui Guo ◽  
Dianyun Ren ◽  
Xin Jin ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Transcriptional Activation ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Gene Sets ◽  
And Migration

AbstractNR5A2 is a transcription factor regulating the expression of various oncogenes. However, the role of NR5A2 and the specific regulatory mechanism of NR5A2 in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly studied. In our study, Western blotting, real-time PCR, and immunohistochemistry were conducted to assess the expression levels of different molecules. Wound-healing, MTS, colony formation, and transwell assays were employed to evaluate the malignant potential of pancreatic cancer cells. We demonstrated that NR5A2 acted as a negative prognostic biomarker in PDAC. NR5A2 silencing inhibited the proliferation and migration abilities of pancreatic cancer cells in vitro and in vivo. While NR5A2 overexpression markedly promoted both events in vitro. We further identified that NR5A2 was transcriptionally upregulated by BRD4 in pancreatic cancer cells and this was confirmed by Chromatin immunoprecipitation (ChIP) and ChIP-qPCR. Besides, transcriptome RNA sequencing (RNA-Seq) was performed to explore the cancer-promoting effects of NR5A2, we found that GDF15 is a component of multiple down-regulated tumor-promoting gene sets after NR5A2 was silenced. Next, we showed that NR5A2 enhanced the malignancy of pancreatic cancer cells by inducing the transcription of GDF15. Collectively, our findings suggest that NR5A2 expression is induced by BRD4. In turn, NR5A2 activates the transcription of GDF15, promoting pancreatic cancer progression. Therefore, NR5A2 and GDF15 could be promising therapeutic targets in pancreatic cancer.

scholarly journals TGF Beta Induces Vitamin D Receptor and Modulates Mitochondrial Activity of Human Pancreatic Cancer Cells

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2932
Author(s):  
Camilla Fiz ◽  
Giulia Apprato ◽  
Chiara Ricca ◽  
Alessia Aillon ◽  
Loredana Bergandi ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Vitamin D ◽  
Cancer Progression ◽  
Vitamin D Receptor ◽  
Metabolic Effects ◽  
Human Pancreatic Cancer ◽  
Mitochondrial Activity ◽  
Low Doses ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells

The inflammatory cytokine TGFβ is both a tumor suppressor during cancer initiation and a promoter of metastasis along cancer progression. Inflammation and cancer are strictly linked, and cancer onset often correlates with the insufficiency of vitamin D, known for its anti-inflammatory properties. In this study, we investigated the interplay between TGFβ and vitamin D in two models of human pancreatic cancer, and we analyzed the metabolic effects of a prolonged TGFβ treatment mimicking the inflammatory environment of pancreatic cancer in vivo. We confirmed the induction of the vitamin D receptor previously described in epithelial cells, but the inhibitory effects of vitamin D on epithelial–mesenchymal transition (EMT) were lost when the hormone was given after a long treatment with TGFβ. Moreover, we detected an ROS-mediated toxicity of the acute treatment with TGFβ, whereas a chronic exposure to low doses had a protumorigenic effect. In fact, it boosted the mitochondrial respiration and cancer cell migration without ROS production and cytotoxicity. Our observations shed some light on the multifaceted role of TGFβ in tumor progression, revealing that a sustained exposure to TGFβ at low doses results in an irreversibly increased EMT associated with a metabolic modulation which favors the formation of metastasis.

scholarly journals Nrf2 Activation Sensitizes K-Ras Mutant Pancreatic Cancer Cells to Glutaminase Inhibition

2021 ◽  
Vol 22 (4) ◽  
pp. 1870
Author(s):  
Shin Hamada ◽  
Ryotaro Matsumoto ◽  
Yu Tanaka ◽  
Keiko Taguchi ◽  
Masayuki Yamamoto ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Progression ◽  
Anticancer Agents ◽  
Therapeutic Interventions ◽  
Human Pancreatic Cancer ◽  
Pancreatic Cancers ◽  
Pancreatic Cancer Cells ◽  
Nrf2 Activation

Pancreatic cancer remains intractable owing to the lack of effective therapy for unresectable cases. Activating mutations of K-ras are frequently found in pancreatic cancers, but these have not yet been targeted by cancer therapies. The Keap1-Nrf2 system plays a crucial role in mediating the oxidative stress response, which also contributes to cancer progression. Nrf2 activation reprograms the metabolic profile to promote the proliferation of cancer cells. A recent report suggested that K-ras- and Nrf2-active lung cancer cells are sensitive to glutamine depletion. This finding led to the recognition of glutaminase inhibitors as novel anticancer agents. In the current study, we used murine pancreatic cancer tissues driven by mutant K-ras and p53 to establish cell lines expressing constitutively activated Nrf2. Genetic or pharmacological Nrf2 activation in cells via Keap1 deletion or Nrf2 activation sensitized cells to glutaminase inhibition. This phenomenon was confirmed to be dependent on K-ras activation in human pancreatic cancer cell lines harboring mutant K-ras, i.e., Panc-1 and MiaPaCa-2 in response to DEM pretreatment. This phenomenon was not observed in BxPC3 cells harboring wildtype K-ras. These results indicate the possibility of employing Nrf2 activation and glutaminase inhibition as novel therapeutic interventions for K-ras mutant pancreatic cancers.

Influence of IP-10/CXCL10 induction in human pancreatic cancer stroma on lymphocytes recruitment and correlation with survival.

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 290-290 ◽  
Author(s):  
Thomas B Brunner ◽  
Serena Lunardi ◽  
Nigel B Jamieson ◽  
Su Yin Lim ◽  
Kristin L Griffiths ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
T Cells ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Cancer Patients ◽  
Mononuclear Cells ◽  
Pancreatic Stellate Cells ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Tumors ◽  
Pancreatic Cancer Cells

290 Background: Pancreatic ductal adenocarcinoma is characterized by an abundant desmoplastic reaction driven by pancreatic stellate cells (PSCs) that contributes to tumor progression. Here we sought to characterize the interactions between pancreatic cancer cells (PCCs) and PSCs that affect the inflammatory and immune response in pancreatic tumors. Methods: Conditioned media from mono- and cocultures of PSCs and PCCs were assayed for expression of cytokines, chemokines and growth factors. Gene expression analysis of human pancreatic ductal adenocarcinoma samples was used to verify expression of cytokines and their correlation with markers of immunoresponse and with clinical outcome. Finally, we tested chemotaxis of leukocytes isolated from peripheral blood mononuclear cells of pancreatic cancer patients. Results: IP-10/CXCL10 was the most highly induced chemokine in coculture of PSCs and PCCs. Its expression was induced in the PSCs by PCCs. IP-10 expression was consistently upregulated in human pancreatic cancer specimens, and positively correlated with high stroma content. Furthermore, expression of IP-10 and its receptor CXCR3 were significantly associated with the intratumoral presence of regulatory T cells (Tregs). In an independent cohort of 48 patients with resectable pancreatic ductal adenocarcinoma, the survival of patients with high IP-10 levels was 18.1 months less than those with low IP-10 levels (HR=2.14, 95% CI 1.05 -4.42). Importantly, IP-10 stimulated the ex vivo recruitment of CXCR3+ effector T cells as well as CXCR3+ Tregs derived from patients with pancreatic cancer. Conclusions: Our findings suggest that, in pancreatic cancer patients, CXCR3+ Tregs are recruited by IP-10 expressed by PSCs in the tumor stroma, leading to immunosuppressive and tumor-promoting effects.

scholarly journals HNF1A is a novel oncogene that regulates human pancreatic cancer stem cell properties

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Ethan V Abel ◽  
Masashi Goto ◽  
Brian Magnuson ◽  
Saji Abraham ◽  
Nikita Ramanathan ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Target Genes ◽  
Bioinformatic Analysis ◽  
Gene Signature ◽  
Biological Properties ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Marker Expression

The biological properties of pancreatic cancer stem cells (PCSCs) remain incompletely defined and the central regulators are unknown. By bioinformatic analysis of a human PCSC-enriched gene signature, we identified the transcription factor HNF1A as a putative central regulator of PCSC function. Levels of HNF1A and its target genes were found to be elevated in PCSCs and tumorspheres, and depletion of HNF1A resulted in growth inhibition, apoptosis, impaired tumorsphere formation, decreased PCSC marker expression, and downregulation of POU5F1/OCT4 expression. Conversely, HNF1A overexpression increased PCSC marker expression and tumorsphere formation in pancreatic cancer cells and drove pancreatic ductal adenocarcinoma (PDA) cell growth. Importantly, depletion of HNF1A in xenografts impaired tumor growth and depleted PCSC marker-positive cells in vivo. Finally, we established an HNF1A-dependent gene signature in PDA cells that significantly correlated with reduced survivability in patients. These findings identify HNF1A as a central transcriptional regulator of PCSC properties and novel oncogene in PDA.

scholarly journals Overexpression of DCLK1-AL Increases Tumor Cell Invasion, Drug Resistance, and KRAS Activation and Can Be Targeted to Inhibit Tumorigenesis in Pancreatic Cancer

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dongfeng Qu ◽  
Nathaniel Weygant ◽  
Jiannan Yao ◽  
Parthasarathy Chandrakesan ◽  
William L. Berry ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Drug Resistance ◽  
Mouse Models ◽  
Pancreatic Tumor ◽  
Fold Increase ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Pdac Tissue

Oncogenic KRAS mutation plays a key role in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis with nearly 95% of PDAC harboring mutation-activated KRAS, which has been considered an undruggable target. Doublecortin-like kinase 1 (DCLK1) is often overexpressed in pancreatic cancer, and recent studies indicate that DCLK1+ PDAC cells can initiate pancreatic tumorigenesis. In this study, we investigate whether overexpressing DCLK1 activates RAS and promotes tumorigenesis, metastasis, and drug resistance. Human pancreatic cancer cells (AsPC-1 and MiaPaCa-2) were infected with lentivirus and selected to create stable DCLK1 isoform 2 (alpha-long, AL) overexpressing lines. The invasive potential of these cells relative to vector control was compared using Matrigel coated transwell assay. KRAS activation and interaction were determined by a pull-down assay and coimmunoprecipitation. Gemcitabine, mTOR (Everolimus), PI3K (LY-294002), and BCL-2 (ABT-199) inhibitors were used to evaluate drug resistance downstream of KRAS activation. Immunostaining of a PDAC tissue microarray was performed to detect DCLK1 alpha- and beta-long expression. Analysis of gene expression in human PDAC was performed using the TCGA PAAD dataset. The effects of targeting DCLK1 were studied using xenograft and Pdx1CreKrasG12DTrp53R172H/+ (KPC) mouse models. Overexpression of DCLK1-AL drives a more than 2-fold increase in invasion and drug resistance and increased the activation of KRAS. Evidence from TCGA PAAD demonstrated that human PDACs expressing high levels of DCLK1 correlate with activated PI3K/AKT/MTOR-pathway signaling suggesting greater KRAS activity. High DCLK1 expression in normal adjacent tissue of PDAC correlated with poor survival and anti-DCLK1 mAb inhibited pancreatic tumor growth in vivo in mouse models.

scholarly journals Development of resistance to FAK inhibition in pancreatic cancer is linked to stromal depletion

Gut ◽  
2019 ◽  
Vol 69 (1) ◽  
pp. 122-132 ◽  
Author(s):  
Hong Jiang ◽  
Xiuting Liu ◽  
Brett L Knolhoff ◽  
Samarth Hegde ◽  
Kyung Bae Lee ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Mouse Models ◽  
Transforming Growth Factor ◽  
Inhibitor Therapy ◽  
Janus Kinase ◽  
Gene Set Enrichment Analysis ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Kpc Mice ◽  
Stat3 Signalling

ObjectiveWe investigated how pancreatic cancer developed resistance to focal adhesion kinase (FAK) inhibition over time.DesignPancreatic ductal adenocarcinoma (PDAC) tumours from KPC mice (p48-CRE; LSL-KRasG12D/wt; p53flox/wt) treated with FAK inhibitor were analysed for the activation of a compensatory survival pathway in resistant tumours. We identified pathways involved in the regulation of signal transducer and activator of transcription 3 (STAT3) signalling on FAK inhibition by gene set enrichment analysis and verified these outcomes by RNA interference studies. We also tested combinatorial approaches targeting FAK and STAT3 in syngeneic transplantable mouse models of PDAC and KPC mice.ResultsIn KPC mice, the expression levels of phosphorylated STAT3 (pSTAT3) were increased in PDAC cells as they progressed on FAK inhibitor therapy. This progression corresponded to decreased collagen density, lowered numbers of SMA+ fibroblasts and downregulation of the transforming growth factor beta (TGF-β)/SMAD signalling pathway in FAK inhibitor-treated PDAC tumours. Furthermore, TGF-β production by fibroblasts in vitro drives repression of STAT3 signalling and enhanced responsiveness to FAK inhibitor therapy. Knockdown of SMAD3 in pancreatic cancer cells abolished the inhibitory effects of TGF-β on pSTAT3. We further found that tumour-intrinsic STAT3 regulates the durability of the antiproliferative activity of FAK inhibitor, and combinatorial targeting of FAK and Janus kinase/STAT3 act synergistically to suppress pancreatic cancer progression in mouse models.ConclusionStromal depletion by FAK inhibitor therapy leads to eventual treatment resistance through the activation of STAT3 signalling. These data suggest that, similar to tumour-targeted therapies, resistance mechanisms to therapies targeting stromal desmoplasia may be critical to treatment durability.

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