Microbiome signatures associated with clinical stages of gastric Cancer: whole metagenome shotgun sequencing study

BACKGROUND

Gastric cancer is one of the global health concerns. A series of studies on the stomach have confirmed the role of the microbiome in shaping gastrointestinal diseases. Delineation of microbiome signatures to distinguish chronic gastritis from gastric cancer will provide a non-invasive preventative and treatment strategy. In this study, we performed whole metagenome shotgun sequencing of fecal samples to enhance the detection of rare bacterial species and increase genome sequence coverage. Additionally, we employed multiple bioinformatics approaches to investigate the potential targets of the microbiome as an indicator of differentiating gastric cancer from chronic gastritis.

RESULTS

A total of 65 patients were enrolled, comprising 33 individuals with chronic gastritis and 32 with gastric cancer. Within each group, the chronic gastritis group was sub-grouped into intestinal metaplasia (n = 15) and non-intestinal metaplasia (n = 18); the gastric cancer group, early stage (stages 1 and 2, n = 13) and late stage (stages 3 and 4, n = 19) cancer. No significant differences in alpha and beta diversities were detected among the patient groups. However, in a two-group univariate comparison, higher Fusobacteria abundance was identified in phylum; Fusobacteria presented higher abundance in gastric cancer (LDA scored 4.27, q = 0.041 in LEfSe). Age and sex-adjusted MaAsLin and Random Forest variable of importance (VIMP) analysis in species provided meaningful features; Bacteria_caccae was the most contributing species toward gastric cancer and late-stage cancer (beta:2.43, se:0.891, p:0.008, VIMP score:2.543). In contrast, Bifidobacterium_longum significantly contributed to chronic gastritis (beta:-1.8, se:0.699, p:0.009, VIMP score:1.988). Age, sex, and BMI-adjusted MasAsLin on metabolic pathway analysis showed that GLCMANNANAUT-PWY degradation was higher in gastric cancer and one of the contributing species was Fusobacterium_varium.

CONCLUSION

Microbiomes belonging to the pathogenic phylum Fusobacteria and species Bacteroides_caccae and Streptococcus_anginosus can be significant targets for monitoring the progression of gastric cancer. Whereas Bifidobacterium_longum and Lachnospiraceae_bacterium_5_1_63FAA might be protection biomarkers against gastric cancer.

ASPM Activates Hedgehog and Wnt Signaling to Promote Small Cell Lung Cancer Stemness and Progression

Small cell lung cancer (SCLC) is among the most aggressive and lethal human malignancies. Most patients with SCLC who initially respond to chemotherapy develop disease relapse. Therefore, there is a pressing need to identify novel driver mechanisms of SCLC progression to unlock treatment strategies to improve patient prognosis. SCLC cells comprise subsets of cells possessing progenitor or stem cell properties, while the underlying regulatory pathways remain elusive. Here, we identified the isoform 1 of the neurogenesis-associated protein ASPM (ASPM-I1) as a prominently upregulated stemness-associated gene during the self-renewal of SCLC cells. The expression of ASPM-I1 was found to be upregulated in SCLC cells and tissues, correlated with poor patient prognosis, and indispensable for SCLC stemness and tumorigenesis. A reporter array screening identified multiple developmental signaling pathways, including Hedgehog (Hh) and Wnt pathways, whose activity in SCLC cells depended upon ASPM-I1 expression. Mechanistically, ASPM-I1 stabilized the Hh transcriptional factor GLI1 at the protein level through a unique exon-18-encoded region by competing with the E3 ligases β-TrCP and CUL3. In parallel, ASPM-I1 sustains the transcription of the Hh pathway transmembrane regulator SMO through the Wnt-DVL3-β-catenin signaling axis. Functional studies verified that the ASPM-I1-regulated Hh and Wnt activities significantly contributed to SCLC aggressiveness in vivo. Consistently, the expression of ASPM-I1 positively correlated with GLI1 and stemness markers in SCLC tissues. This study illuminates an ASPM-I1-mediated regulatory module that drives tumor stemness and progression in SCLC, providing an exploitable diagnostic and therapeutic target.

SIGNIFICANCE

ASPM promotes SCLC stemness and aggressiveness by stabilizing the expression of GLI1, DVL3, and SMO, representing a novel regulatory hub of Hh and Wnt signaling and targetable vulnerability.

Arthrospira Enhances Seroclearance in Patients with Chronic Hepatitis B Receiving Nucleos(t)ide Analogue through Modulation of TNF-α/IFN-γ Profile

Chronic hepatitis B (CHB) virus infection, causing immune dysfunction and chronic hepatitis, is one of the leading risk factors for hepatocellular cancer. We investigated how Arthrospira affected hepatitis B surface antigen (HBsAg) reduction in CHB patients under continued nucleos(t)ide analogues (NA). Sixty CHB patients who had been receiving NA for at least one year with undetectable HBV DNA were randomized into three groups: control and oral Arthrospira at 3 or 6 g daily add-on therapy groups. Patients were followed up for 6 months. Oral Arthrospira-diet mice were established to investigate the possible immunological mechanism of Arthrospira against HBV. Within 6 months, mean quantitative HBsAg (qHBsAg) decreased in the oral Arthrospira add-on therapy group. Interestingly, interferon gamma (IFN-γ) increased but TNF-α, interleukin 6 (IL-6), hepatic fibrosis, and steatosis decreased in the add-on groups. In mice, Arthrospira enhanced both innate and adaptive immune system, especially natural killer (NK) cell cytotoxicity, B cell activation, and the interleukin 2 (IL-2), IFN-γ immune response. Arthrospira may modulate IL-2- and TNF-α/IFN-γ-mediated B and T cell activation to reduce HBsAg. Also, Arthrospira has the potential to restore immune tolerance and enhance HBsAg seroclearance in CHB patients through promoting T, B, and NK cell activation.

Histone Deacetylase Inhibitors Downregulate Calcium Pyrophosphate Crystal Formation in Human Articular Chondrocytes

Calcium pyrophosphate (CPP) deposition disease (CPPD) is a form of CPP crystal-induced arthritis. A high concentration of extracellular pyrophosphate (ePPi) in synovial fluid is positively correlated with the formation of CPP crystals, and ePPi can be upregulated by ankylosis human (ANKH) and ectonucleotide pyrophosphatase 1 (ENPP1) and downregulated by tissue non-specific alkaline phosphatase (TNAP). However, there is currently no drug that eliminates CPP crystals. We explored the effects of the histone deacetylase (HDAC) inhibitors (HDACis) trichostatin A (TSA) and vorinostat (SAHA) on CPP formation. Transforming growth factor (TGF)-β1-treated human primary cultured articular chondrocytes (HC-a cells) were used to increase ePPi and CPP formation, which were determined by pyrophosphate assay and CPP crystal staining assay, respectively. Artificial substrates thymidine 5′-monophosphate p-nitrophenyl ester (p-NpTMP) and p-nitrophenyl phosphate (p-NPP) were used to estimate ENPP1 and TNAP activities, respectively. The HDACis TSA and SAHA significantly reduced mRNA and protein expressions of ANKH and ENPP1 but increased TNAP expression in a dose-dependent manner in HC-a cells. Further results demonstrated that TSA and SAHA decreased ENPP1 activity, increased TNAP activity, and limited levels of ePPi and CPP. As expected, both TSA and SAHA significantly increased the acetylation of histones 3 and 4 but failed to block Smad-2 phosphorylation induced by TGF-β1. These results suggest that HDACis prevented the formation of CPP by regulating ANKH, ENPP1, and TNAP expressions and can possibly be developed as a potential drug to treat or prevent CPPD.

Percutaneous endoscopic gastrostomy prior to esophagectomy for esophageal cancer - a systematic review and meta-analysis

BACKGROUND

For resectable esophageal cancer (EC), it remains controversial whether to place percutaneous endoscopic gastrostomy (PEG) before the curative surgery to provide nutritional support during the neoadjuvant therapy.

OBJECTIVE

To compare surgical outcomes for patients who received preoperative PEG and those without PEG placement (No-PEG) insertion prior to surgery in a potentially operable EC.

METHODS

A comprehensive literature search was conducted to identify randomized and non-randomized studies comparing PEG and No-PEG groups.

RESULTS

Four retrospective studies with a total number of 1,027 patients were identified and included in this meta-analysis. The differences in anastomotic leakage, anastomotic stricture, morbidity, pulmonary complications, wound infection, and hospital stay were not statistically significant between the two groups. Operation time was significantly shorter in the PEG group. There was no PEG-related gastric conduit failure and no leak from the PEG site in the PEG group.

CONCLUSION

We conclude preoperative PEG for resectable EC is a safe procedure with no adverse effect on the gastric tube construction and anastomosis, it can be selectively inserted for EC patients with marked weight loss and malnutrition or those at risk of developing malnutrition during neoadjuvant therapy.

MCPIP1 Enhances TNF-α-Mediated Apoptosis through Downregulation of the NF-κB/cFLIP Axis

Monocyte chemoattractant protein-1-induced protein 1 (MCPIP1) is rapidly produced under proinflammatory stimuli, thereby feeding back to downregulate excessive inflammation. In this study, we used the stable, inducible expressions of wild-type (WT) MCPIP1 and an MCPIP1-D141N mutant in T-REx-293 cells by means of a tetracycline on (Tet-on) system. We found that WT MCPIP1 but not MCPIP1-D141N mutant expression dramatically increased apoptosis, caspase-3, -7, -8, and -9 activation, and c-Jun N-terminal kinase (JNK) phosphorylation in TNF-α-treated cells. The pan-caspase inhibitor, z-VAD-fmk, and the caspase-1 inhibitor, z-YVAD-fmk, but not the JNK inhibitor, SP600125, significantly reversed apoptosis and caspase activation in TNF-α/MCPIP1-treated cells. Surprisingly, MCPIP1 itself was also cleaved, and the cleavage was suppressed by treatment with the pan-caspase inhibitor and caspase-1 inhibitor. Moreover, MCPIP1 was found to contain a caspase-1/-4 consensus recognition sequence located in residues 234~238. As expected, the WT MCPIP1 but not the MCPIP1-D141N mutant suppressed NF-κB activation, as evidenced by inhibition of IκB kinase (IKK) phosphorylation and IκB degradation using Western blotting, IKK activity using in vitro kinase activity, and NF-κB translocation to nuclei using an immunofluorescence assay. Interestingly, MCPIP1 also significantly inhibited importin α3 and importin α4 expressions, which are major nuclear transporter receptors for NF-κB. Inhibition of NF-κB activation further downregulated expression of the caspase-8 inhibitor, cFLIP. In summary, the results suggest that MCPIP1 could enhance the TNF-α-induced apoptotic pathway through decreasing NF-κB activation and cFLIP expression.

A Novel Invadopodia-Specific Marker for Invasive and Pro-Metastatic Cancer Stem Cells

Introduction

Stem-like cancer cells or cancer stem cells (CSCs) may comprise a phenotypically and functionally heterogeneous subset of cells, whereas the molecular markers reflecting this CSC hierarchy remain elusive. The glycolytic enzyme alpha-enolase (ENO1) present on the surface of malignant tumor cells has been identified as a metastasis-promoting factor through its function of activating plasminogen. The expression pattern of surface ENO1 (sENO1) concerning cell-to-cell or CSC heterogeneity and its functional roles await further investigation.

Methods

The cell-to-cell expression heterogeneity of sENO1 was profiled in malignant cells from different types of cancers using flow cytometry. The subcellular localization of sENO1 and its functional roles in the invadopodia formation and cancer cell invasiveness were investigated using a series of imaging, molecular, and in vitro and in vivo functional studies.

Results

We showed here that ENO1 is specifically localized to the invadopodial surface of a significant subset (11.1%-63.9%) of CSCs in human gastric and prostate adenocarcinomas. sENO1⁺ CSCs have stronger mesenchymal properties than their sENO1^- counterparts. The subsequent functional studies confirmed the remarkable pro-invasive and pro-metastatic capacities of sENO1⁺ CSCs. Mechanistically, inhibiting the surface localization of ENO1 by downregulating caveolin-1 expression compromised invadopodia biogenesis, proteolysis, and CSC invasiveness.

Conclusions

Our study identified the specific expression of ENO1 on the invadopodial surface of a subset of highly invasive and pro-metastatic CSCs. sENO1 may provide a diagnostically and/or therapeutically exploitable target to improve the outcome of patients with aggressive and metastatic cancers.

A multi-mode Wnt- and stemness-regulatory module dictated by FOXM1 and ASPM isoform I in gastric cancer

BACKGROUND

Gastric cancer (GC) is the third leading cause of cancer mortality globally and a molecularly heterogeneous disease. Identifying the driver pathways in GC progression is crucial to improving the clinical outcome. Recent studies identified ASPM (abnormal spindle-like microcephaly-associated) and FOXM1 (Forkhead box protein M1) as novel Wnt and cancer stem cell (CSC) regulators; their pathogenetic roles and potential crosstalks in GC remain unclarified.

METHODS

The expression patterns of ASPM isoforms and FOXM1 were profiled in normal gastric epithelial and GC tissues. The functional roles of ASPM and FOXM1 in Wnt activity, cancer stemness and GC progression, and the underlying signaling processes were investigated.

RESULTS

Approximately one third of GC cells upregulate the expression of ASPM isoform I (ASPMiI) in their cytoplasm; the tumors with a high ASPMiI positive score (≥ 10%) are associated with a poor prognosis of the patients. Mechanistically, the molecular interplay among FOXM1, ASPMiI and DVL3 was found to converge on β-catenin to control the Wnt activity and the stemness property of GC cells. This multi-mode Wnt-regulatory module serves to reinforce Wnt signals in CSCs by transcriptional regulation (FOXM1-ASPM), protein-protein interactions (ASPMiI-DVL3-β-catenin), and nuclear translocation (FOXM1-β-catenin).

CONCLUSIONS

This study illuminates a novel Wnt- and stemness-regulatory mechanism in GC cells and identifies a novel subset of FOXM1^highASPMiI^high GC with potential to guide Wnt- and stemness-related diagnostics and therapies.

Dishevelled 1-Regulated Superpotent Cancer Stem Cells Mediate Wnt Heterogeneity and Tumor Progression in Hepatocellular Carcinoma

Various populations of cancer stem cells (CSCs) have been identified in hepatocellular carcinoma (HCC). Wnt signaling is variably activated in HCC and regulates CSCs and tumorigenesis. We explored cell-to-cell Wnt and stemness heterogeneity in HCC by labeling freshly isolated cancer cells with a Wnt-specific reporter, thereby identifying a small subset (0.4%–8.9%) of Wnt-activity^high cells. Further cellular subset analysis identified a refined subset of Wnt-activity^highALDH1⁺EpCAM⁺ triple-positive (TP) cells as the most stem-like, phenotypically plastic, and tumorigenic among all putative CSC populations. These TP “superpotent CSCs” (spCSCs) specifically upregulate the expression of dishevelled 1 (DVL1) through the antagonism between abnormal spindle-like microcephaly-associated (ASPM) and the ubiquitin ligase complex Cullin-3/KLHL-12. Subsequent functional and molecular studies revealed the role of DVL1 in controlling spCSCs and their tumorigenic potential. These findings provide the mechanistic basis of the Wnt and stemness heterogeneity in HCC and highlight the important role of DVL1^high spCSCs in tumor progression.

•

Wnt activity displays a high degree of intratumoral heterogeneity in HCC

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Wnt-activity^highALDH1⁺EPCAM⁺ cells are identified as superpotent CSCs in HCC

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The proportion of superpotent CSCs correlates with poor patient prognosis in HCC

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Superpotent CSCs are regulated by the Wnt-ASPM-DVL1 signaling axis

Safety and efficacy of magnetic seed localisation of non-palpable breast lesions: pilot study in a Chinese population

INTRODUCTION

A magnetic seed marker system (Magseed, Endomagnetics, Cambridge, United Kingdom) is used as a localisation method for non-palpable breast lesions in the United States, Europe, and Hong Kong. It overcomes many limitations of conventional techniques and allows scheduling flexibility. We sought to evaluate its efficacy and safety in the Chinese population.

METHODS

We retrospectively reviewed all Chinese women who underwent magnetic seed marker-guided breast lesion excision from June 2019 to February 2020 at a single institution. Placement success (final target-to-seed distance <10 mm) was evaluated by imaging on the day of surgery. Specimen radiographs and pathology reports were reviewed for magnetic seed markers and target removal. Margin clearance and re-excision rates were analysed.

RESULTS

Twenty two magnetic seed markers were placed in 21 patients under sonographic or stereotactic guidance to localise 21 target lesions. One target lesion required two magnetic seed markers for bracketing. There was no migration of nine markers placed 6 to 56 days before the day of surgery. Placement success was achieved in 20 (90.9%) cases. Mean final target-to-seed distance was 3.1 mm. Two out of 21 (9.5%) lesions required alternative localisation due to marker migration ≥10 mm, while 19 (90.5%) lesions underwent successful magnetic seed marker-guided excision. Three of these 19 lesions (15.8%) were excised with therapeutic intent, one of which (33%) required re-excision due to a close margin. All 22 magnetic seed markers were successfully removed. No complications were reported.

CONCLUSION

Magnetic seed markers demonstrated safety and efficacy in Chinese women for breast lesion localisation and excision.

The anatomical locations of postoperative pain and their recovery trajectories following Posterior Spinal Fusion (PSF) surgery in Adolescent Idiopathic Scoliosis (AIS) patients

INTRODUCTION

This study looked into the different anatomical locations of pain and their trajectories within the first two weeks after Posterior Spinal Fusion (PSF) surgery for Adolescent Idiopathic Scoliosis (AIS).

METHODS

We prospectively recruited patients with Adolescent Idiopathic Scoliosis (AIS) scheduled for PSF surgery. The anatomical locations of pain were divided into four: (1) surgical wound pain; (2) shoulder pain; (3) neck pain; and (4) low back pain. The anatomical locations of pain were charted using the visual analogue pain score at intervals of 12, 24, 36, 48 hours; and from day-3 to -14. Patient-controlled analgesia (morphine), use of celecoxib capsules, acetaminophen tablets and oxycodone hydrochloride capsule consumption were recorded.

RESULTS

A total of 40 patients were recruited. Patients complained of surgical wound pain score of 6.2±2.1 after surgery. This subsequently reduced to 4.2±2.0 by day-4, and to 2.4±1.3 by day-7. Shoulder pain scores of symptomatic patients peaked to 4.2±2.7 at 24 hours and 36 hours which then reduced to 1.8±1.1 by day-8. Neck pain scores of symptomatic patients reduced from 4.2±1.9 at 12 hours to 1.8±1.1 by day-4. Low back pain scores of symptomatic patients reduced from 5.3±2.3 at 12 hours to 1.8±1.1 by day- 12.

CONCLUSIONS

Despite the presence of different anatomical locations of pain after surgery, surgical wound was the most significant pain and other anatomical locations of pain were generally mild. Surgical wound pain reduced to a tolerable level by day-4 when patients can then be comfortably discharged. This finding provides useful information for clinicians, patients and their caregivers.

The differential distributions of ASPM isoforms and their roles in Wnt signaling, cell cycle progression, and pancreatic cancer prognosis

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and treatment‐resistant malignancy. The lack of pathway‐informed biomarkers hampers the development of rational diagnostics or therapies. Recently, the protein abnormal spindle‐like microcephaly‐associated (ASPM) was identified as a novel Wnt and stemness regulator in PDAC, while the pathogenic roles of its protein isoforms remain unclarified. We developed novel isoform‐specific antibodies and genetic knockdown (KD) of putative ASPM isoforms, whereby we uncovered that the levels of ASPM isoform 1 (iI) and ASPM‐iII are variably upregulated in PDAC cells. ASPM isoforms show remarkably different subcellular locations; specifically, ASPM‐iI is exclusively localized to the cortical cytoplasm of PDAC cells, while ASPM‐iII is predominantly expressed in cell nuclei. Mechanistically, ASPM‐iI co‐localizes with disheveled‐2 and active β‐catenin as well as the stemness marker aldehyde dehydrogenase‐1 (ALDH‐1), and its expression is indispensable for the Wnt activity, stemness, and the tumorigenicity of PDAC cells. By contrast, ASPM‐iII selectively regulates the expression level of cyclin E and cell cycle progression in PDAC cells. The expression of ASPM‐iI and ASPM‐iII displays considerable intratumoral heterogeneity in PDAC tissues and only that of ASPM‐iI was prognostically significant; it outperformed ALDH‐1 staining and clinico‐pathological variables in a multivariant analysis. Collectively, the distinct expression patterns and biological functions of ASPM isoforms may illuminate novel molecular mechanisms and prognosticators in PDAC and may pave the way for the development of therapies targeting this novel oncoprotein. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Targeting the Interplay Between Cancer Fibroblasts, Mesenchymal Stem Cells, and Cancer Stem Cells in Desmoplastic Cancers

Malignant tumors are highly heterogeneous and likely contain a subset of cancer cells termed cancer stem cells (CSCs). CSCs exist in a dynamic equilibrium with their microenvironments and the CSC phenotype is tightly regulated by both cell-intrinsic and cell-extrinsic factors including those derived from their surrounding cells or stroma. Many human solid tumors like breast, lung, colorectal and pancreatic cancers are characterized by a pronounced stromal reaction termed “the desmoplastic response.” Carcinoma-associated fibroblasts (CAFs) derived either from resident fibroblasts or tumor-infiltrating mesenchymal stem cells (MSCs) are a major component of the stroma in desmoplastic cancers. Recent studies identified subpopulations of CAFs proficient in secreting a plethora of factors to foster CSCs, tumor growth, and invasion. In addition, cytotoxic therapy can lead to the enrichment of functionally perturbed CAFs, which are endowed with additional capabilities to enhance cancer stemness, leading to treatment resistance and tumor aggressiveness. When recruited into the tumor stroma, bone-marrow-derived MSCs can promote cancer stemness by secreting a specific set of paracrine factors or converting into pro-stemness CAFs. Thus, blockade of the crosstalk of pro-stemness CAFs and MSCs with CSCs may provide a new avenue to improving the therapeutic outcome of desmoplastic tumors. This up-to-date, in-depth and balanced review describes the recent progress in understanding the pro-stemness roles of CAFs and tumor-infiltrating MSCs and the associated paracrine signaling processes. We emphasize the effects of systemic chemotherapy on the CAF/MSC–CSC interplay. We summarize various promising and novel approaches in mitigating the stimulatory effect of CAFs or MSCs on CSCs that have shown efficacies in preclinical models of desmoplastic tumors and highlight the unique advantages of CAF- or MSC-targeted therapies. We also discuss potential challenges in the clinical development of CSC- or MSC-targeted therapies and propose CAF-related biomarkers that can guide the next-generation clinical studies.

Next Viable Routes to Targeting Pancreatic Cancer Stemness: Learning from Clinical Setbacks

Pancreatic ductal adenocarcinoma (PDAC) is a devastating and highly aggressive malignancy. Existing therapeutic strategies only provide a small survival benefit in patients with PDAC. Laboratory and clinical research have identified various populations of stem-cell-like cancer cells or cancer stem cells (CSCs) as the driving force of PDAC progression, treatment-resistance, and metastasis. Whilst a number of therapeutics aiming at inhibiting or killing CSCs have been developed over the past decade, a series of notable clinical trial setbacks have led to their deprioritization from the pipelines, triggering efforts to refine the current CSC model and exploit alternative therapeutic strategies. This review describes the current and the evolving models of pancreatic CSCs (panCSCs) and the potential factors that hamper the clinical development of panCSC-targeted therapies, emphasizing the heterogeneity, the plasticity, and the non-binary pattern of cancer stemness, as well as the desmoplastic stroma impeding drug penetration. We summarized novel and promising therapeutic strategies implicated by the works of our groups and others' that may overcome these hurdles and have shown efficacies in preclinical models of PDAC, emphasizing the unique advantages of targeting the stroma-engendered panCSC-niches and metronomic chemotherapy. Finally, we proposed feasible clinical trial strategies and biomarkers that can guide the next-generation clinical trials.

Abstract 538: ASPM promotes prostate cancer tumorigenesis by bolstering cancer stemness through Wnt-Dvl-3-b-catenin signaling

Metastasis is the major cause of cancer mortality in androgen-independent prostate cancer (PCA) and understanding it is crucial to improving the outcome of patients. Recent evidence suggests that activation of Wnt signaling in cancer stem cells (CSCs) contributes to cancer progression in malignant tumors. Here we report that a novel Wnt activator ASPM (Abnormal spindle-like microcephaly associated) maintains the prostate CSC subpopulation through augmenting the Wnt-β-catenin signaling in PCA. Functional studies showed that downregulation of ASPM expression attenuated the proliferation and invasive of PCA cells and reduced the number of prostate CSCs and inhibited cancer stemness and tumorigenesis. Mechanistically, ASPM interacts with dishevelled-3 (Dvl-3) and inhibits its proteasome-dependent degradation, thereby increasing the protein stability of Dvl-3 and enabling the β-catenin transcriptional activity in PCA cells. The clinical significance of the above findings was credentialed by the profound up-regulation of ASPM in metastatic PCA and the strong correlation of cytoplasmic ASPM expression with poor metastasis-free survival of patients with resected PCA. Collectively, our data points to ASPM as a novel oncoprotein and an essential regulator of cancer stemness in PCA, which has important clinical and therapeutic significance (supported by Ministry of Science and Technology grants MOST 104-2314-B-400-022 and MOST 105-2314-B-400-018 and National Health Research Institutes NHRIs grant CA-106-PP-09 to K.K.T).

Citation Format: Kelvin K. Tsai, Vincent C. Pai, Chung-Chi Hsu, Tze-Sian Chan. ASPM promotes prostate cancer tumorigenesis by bolstering cancer stemness through Wnt-Dvl-3-b-catenin signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 538.

Metronomic chemotherapy prevents therapy-induced stromal activation and induction of tumor-initiating cells

Chan et al. report that treatment of tumor-bearing mice with low-dose metronomic chemotherapy prevents stromal secretion of ELR⁺ chemokines and induction of tumor-initiating cells usually observed with administration of drugs at maximum tolerated dose.

Although traditional chemotherapy kills a fraction of tumor cells, it also activates the stroma and can promote the growth and survival of residual cancer cells to foster tumor recurrence and metastasis. Accordingly, overcoming the host response induced by chemotherapy could substantially improve therapeutic outcome and patient survival. In this study, resistance to treatment and metastasis has been attributed to expansion of stem-like tumor-initiating cells (TICs). Molecular analysis of the tumor stroma in neoadjuvant chemotherapy–treated human desmoplastic cancers and orthotopic tumor xenografts revealed that traditional maximum-tolerated dose chemotherapy, regardless of the agents used, induces persistent STAT-1 and NF-κB activity in carcinoma-associated fibroblasts. This induction results in the expression and secretion of ELR motif–positive (ELR⁺) chemokines, which signal through CXCR-2 on carcinoma cells to trigger their phenotypic conversion into TICs and promote their invasive behaviors, leading to paradoxical tumor aggression after therapy. In contrast, the same overall dose administered as a low-dose metronomic chemotherapy regimen largely prevented therapy-induced stromal ELR⁺ chemokine paracrine signaling, thus enhancing treatment response and extending survival of mice carrying desmoplastic cancers. These experiments illustrate the importance of stroma in cancer therapy and how its impact on treatment resistance could be tempered by altering the dosing schedule of systemic chemotherapy.

A gene expression signature of epithelial tubulogenesis and a role for ASPM in pancreatic tumor progression

BACKGROUND & AIMS

Many patients with pancreatic ductal adenocarcinoma (PDAC) develop recurrent or metastatic diseases after surgery, so it is important to identify those most likely to benefit from aggressive therapy. Disruption of tissue microarchitecture is an early step in pancreatic tumorigenesis and a parameter used in pathology grading of glandular tumors. We investigated whether changes in gene expression during pancreatic epithelial morphogenesis were associated with outcomes of patients with PDAC after surgery.

METHODS

We generated architectures of human pancreatic duct epithelial cells in a 3-dimensional basement membrane matrix. We identified gene expression profiles of the cells during different stages of tubular morphogenesis (tubulogenesis) and of PANC-1 cells during spheroid formation. Differential expression of genes was confirmed by immunoblot analysis. We compared the gene expression profile associated with pancreatic epithelial tubulogenesis with that of PDAC samples from 27 patients, as well as with their outcomes after surgery.

RESULTS

We identified a gene expression profile associated with tubulogenesis that resembled the profile of human pancreatic tissue with differentiated morphology and exocrine function. Patients with PDACs with this profile fared well after surgery. Based on this profile, we established a 6-28 gene tubulogenesis-specific signature that accurately determined the prognosis of independent cohorts of patients with PDAC (total n = 128; accuracy = 81.2%-95.0%). One gene, ASPM, was down-regulated during tubulogenesis but up-regulated in human PDAC cell lines and tumor samples; up-regulation correlated with patient outcomes (Cox regression P = .0028). Bioinformatic, genetic, biochemical, functional, and clinical correlative studies showed that ASPM promotes aggressiveness of PDAC by maintaining Wnt-β-catenin signaling and stem cell features of PDAC cells.

CONCLUSIONS

We identified a gene expression profile associated with pancreatic epithelial tubulogenesis and a tissue architecture-specific signature of PDAC cells that is associated with patient outcomes after surgery.

Sacrococcygeal teratoma in adults: case report and literature review

Sacrococcygeal teratoma is one of the most common tumours in infants but rare in adults. We present a case of sacrococcygeal teratoma in a female adult. The clinical presentation, radiological and histological findings, management, and outcome are described.

Enterococcus hirae-related acute pyelonephritis and cholangitis with bacteremia: an unusual infection in humans

Very few reports are available from the literature related to Enterococcus hirae infection in humans, which is more frequently seen in animals and birds. We report two patients with E hirae bacteremia caused by acute pyelonephritis and acute cholangitis. The clinical courses have been smooth on use of sensitive antibiotic therapy. In both cases, the primary sources and portals of entry are clearly identified.

X-Ray spectra and electronic correlations of FeSe(1-x)Te(x)

Critical issues concerning emerging Fe-based superconductors include the degree of electron correlation and the origin of the superconductivity. X-Ray absorption spectra (XAS) and resonant inelastic X-ray scattering spectra (RIXS) of FeSe(1-x)Te(x) (x = 0-1) single crystals were obtained to study their electronic properties that relate to electron correlation and superconductivity. The linewidth of Fe L(2,3)-edges XAS of FeSe(1-x)Te(x) is narrower than that of Fe-pnictides, revealing the difference between their hybridization effects and localization character and those of other Fe-pnictides. While no significant differences exist between the Fe L-edge XAS and RIXS of FeSe(1-x)Te(x) and those of Fe-pnictides, Se K-edge and Te K-edge XAS exhibit substantial edge shift, suggesting that the superconductivity in an Fe-Se superconductor is strongly associated with the ligand states. A comparison of the Se K-edge and Te K-edge spectra reveals that the charge transfer may occur between Se and Te. Given the Coulomb interaction and the bandwidth, the spectral results indicate that FeSe(1-x)Te(x) is unlikely to be a weakly correlated system unlike the Fe-pnictides of the "1111" and "122" families. The spectral results further demonstrate that superconductivity in this class of Fe-based compounds is strongly associated with the ligand 4p hole state.

HPV vaccination in Hong Kong: implications for medical education

OBJECTIVE

To explore the experience and attitudes of physicians in clinics, and to facilitate physicians' promotion of HPV vaccination.

DATA SOURCES

Primary data collected from conducting semi-structural in-depth interviews from May to June 2010 with 12 physicians in one district in Hong Kong to understand their experience of providing HPV vaccines, the difficulties in promoting HPV vaccines, and their attitudes towards HPV vaccination.

STUDY DESIGN

Physicians identified 4 categories of factors related to their experiences of and attitudes to providing HPV vaccination: (a) background information on HPV vaccination provided by physicians, (b) factors influencing women to receive vaccination, (c) physicians' recommendations to the public on HPV vaccines, and (d) physicians' perspectives on HPV vaccine promotion.

CONCLUSIONS

Our findings show that public knowledge on HPV and cervical cancer is insufficient and the role of government in vaccine promotion is unclear. Promotion strategies such as physicians' recommendation, financial assistance and health education provided by the government will influence HPV vaccination and its promotion.

Spin-phonon coupling effects in antiferromagnetic Cr2O3 nanoparticles

In the present work we use Raman microscopy to investigate the size effect of spin-phonon coupling in antiferromagnetic Cr2O3 nanoparticles. The peculiarities of the dependency of the phonon wave number on temperature (with a relatively weak peak at 293 cm(-1)) can be attributed to the spin-phonon coupling. The variation with temperature of the spin-phonon mode develops when the antiferromagnetic state is near the ordering temperature of the Cr spins. The observations can be reasonably well interpreted by describing the order parameter. A shift in frequency is caused by a strong spin-phonon interaction in Cr2O3. The obtained s-ph coefficients are found to be consistent with the strain, where raising the strain results in weakening of the s-ph coupling.

Targeting c-Myc as a novel approach for hepatocellular carcinoma

Hepatocelluar carcinoma (HCC) is the most lethal cancer in the world. Most HCC over-express c-Myc, which plays a critical role in regulating cellular growth, differentiation and apoptosis in both normal and neoplastic cells. c-Myc is among the most frequently overexpressed genes in human cancers. Overexpression of c-Myc in hepatic cells leads to development of hepatocellular carcinoma. Here, we review the current progress in understanding physiologic function and regulation of c-Myc as well as its role in hepatic carcinogenesis and discuss the association of c-Myc activation in chronic hepatitis B infection and the upregulation of HIF-1/VEGF. We also explore the possibility of treating HCC by inhibiting c-Myc and examine the pros and cons of such an approach. Although this strategy is currently not available in clinics, with recent advances in better drug design, pharmacokinetics and pharmacogenetics, inhibition of c-Myc might become a novel therapy for HCC in the future.

Influence of oxygen defects on the crystal structure and magnetic properties of the (Tb1-xNax)MnO3-y (0<or=x<or=0.3) system

The crystallographic and magnetic behaviors of (Tb1-xNax)MnO3-y (0<or=x<or=0.3) have been studied by neutron powder diffraction (NPD), synchrotron X-ray powder diffraction, and Raman spectroscopy techniques. Although Na+ ions have larger ionic radii than Tb3+ ions, analysis of NPD data reveals a decrease in cell volume upon Na-doping, which can be explained solely by the occurrence of oxygen deficiencies and not by the size effect. The Raman spectrum represents the variation in bond length and bond angle, which originates from the balance of ions, asymmetric structure, and defects in the system. Na-doping causes an oxygen deficiency, and consequently, a peak shift is seen in the Raman spectrum because of the structural adjustment resulting from the doping. The observed effective moments decrease with increasing x because of the replacement of Tb3+ ions by Na+ ions. The well-defined peak at approximately 45 K (labeled TMn) of the x=0.3 sample is associated with Mn spin ordering, while the magnetic responses associated with TMn are not clearly present in the x=0.15 and x=0 samples.

Chemical size effect on the magnetic and electrical properties in the (Tb(1-)(x)Eu(x))MnO(3) (0 < or = x < or = 1.0) system

The effect of isovalent chemical substitution of Eu3+ into the Tb3+ sites on the magnetic and electrical properties of (Tb1-xEux)MnO3 (0 </= x </= 1.0) system has been investigated. The orthorhombic structure with space group Pbnm is observed in this series of materials. An increase in Mn-O bond distance with increasing Eu content leads to improvement in the overlap between the Mn 3d and O 2p orbital thereby causing a decrease in activation energy and resistivity. Moreover, as the Eu content increases, the effective moments (mueff) are reduced linearly and an exchange coupling is observed in Tb-Tb, Tb-Eu, and Eu-Eu complexes for x = 0.1 and 0.3 samples. Both these features can be related to the substitution of bigger Eu3+ ions replacing the original Tb-Tb coupling.

Hydrogen peroxide supports hepatocyte P450 catalysed xenobiotic/drug metabolic activation to form cytotoxic reactive intermediates

1. A H2O2 generating system markedly increased the cytotoxicity of catechols, hydroquinone, in isolated hepatocytes, but not in P450 inhibited hepatocytes. 2. H2O2 or NADPH supported microsomal catalysed GSH conjugate formation with catechols or hydroquinone. Cytochrome P450 inhibitors inhibited conjugate formation. However, superoxide dismutase inhibited NADPH, but did not affect H2O2 supported GSH conjugate formation. The conjugate formed with dihydrocaffeic acid was identified as a mono-GSH conjugate indicating that the o-quinone was the major metabolite formed. 3. Dopamine (a catecholamine) induced cytotoxicity was prevented by inhibitors of monoamine oxidase (MAO) or P450, but was markedly increased by hepatocyte catalase inhibition or NAD(P)H:quinone oxidoreductase inhibition. This suggests that H2O2 formed by the mitochondrial metabolism of monoamine oxidase then oxidised dopamine to cytotoxic o-quinone catalysed by P450. Dihydrocaffeic acid cytotoxicity was also increased by the monoamine oxidase substrate tyramine. 4. It is concluded that polyphenolics are oxidised by H2O2/P450 in hepatocytes to form quinone metabolites.

Ventricular dysfunction in a patient with Plummer's disease: a case report

A 76-year-old female patient complained of intermittent palpitation, shortness of breath, and orthopnea for 10 days. The patient was found to have cardiomegaly, left ventricular dilatation secondary to moderate regurgitation, with impaired ventricular dysfunction and persistent sinus tachycardia. The patient also had a nodular goiter with increased uptake on radionuclide scan on the right side of the thyroid gland, low serum thyroid-stimulating hormone, with normal triiodothyronine, and free thyroxine. Plummer's disease with ventricular dysfunction was diagnosed. We present this rare case and a review of the literature.

Hepatitis C virus core and envelope proteins do not suppress the host's ability to clear a hepatic viral infection

Several hepatitis C virus (HCV) proteins have been shown in vitro to interact with host cellular components that are involved in immune regulation. However, there is a paucity of data supporting the relevance of these observations to the in vivo situation. To test the hypothesis that such an interaction suppresses immune responses, we studied a line of transgenic C57BL/6 mice that express the HCV core and envelope proteins in the liver. The potential effects of these proteins on the hepatic immune response were evaluated by challenging these mice with a hepatotropic adenovirus. Both transgenic and nontransgenic mice developed similar courses of infection and cleared the virus from the liver by 28 days postinfection. Both groups of mice mounted similar immunoglobulin G (IgG), IgG2a, interleukin-2, and tumor necrosis factor alpha responses against the virus. Additionally, BALB/c mice were able to clear infection with recombinant adenovirus that does or does not express the HCV core and envelope 1 proteins in the same manner. These data suggest that HCV core and envelope proteins do not inhibit the hepatic antiviral mechanisms in these murine experimental systems and thus favor a model in which HCV circumvents host responses through a mechanism that does not involve general suppression of intrahepatic immune responses.

Flavonoid B-ring chemistry and antioxidant activity: fast reaction kinetics

Rapid scavenging of the model stable radical cation, ABTS(*+), has been applied to screen for the antioxidant activity of flavonoids. The reaction follows two distinct phases. For compounds with a monophenolic B-ring there is a rapid initial phase of reduction of ABTS(*+) within 0.1 s with no further change in the subsequent 2.9 s. In contrast, compounds with a catechol-containing B ring follow a fast initial scavenging phase with a slow secondary phase. Flavonoids with an unsubstituted B ring do not react within this time scale. The findings suggest that the structure of the B ring is the primary determinant of the antioxidant activity of flavonoids when studied through fast reaction kinetics.

Cancer chemoprevention and apoptosis mechanisms induced by dietary polyphenolics

This review summarises current knowledge on the various molecular chemopreventive or therapeutic mechanisms that may be involved when the administration of flavonoids or polyphenols prevented chemical carcinogenesis in animal models. These mechanisms can be subdivided into the following: 1) the molecular mechanisms involved in preventing carcinogen metabolic activation, 2) the molecular mechanisms for preventing tumour cell proliferation by inactivation or downregulation of prooxidant enzymes or signal transduction enzymes, 3) the molecular cell death mechanisms for the induction of tumour cell death (apoptosis) and the molecular mechanisms for the inhibition of isolated mitochondria functions. Many of the flavonoids and polyphenols found in diets, supplements or herbal medicine were also ranked using "accelerated cytotoxic mechanism screening" by a combinatorial approach utilising isolated rat hepatocytes. A strong correlation of an early collapse of the mitochondrial membrane potential and cell death was found for most of the cytotoxic polyphenols but did not occur with non-toxic polyphenols. This screening could prove useful for eliminating polyphenols that have the potential for adverse health effects and for selecting safe and effective polyphenolic candidates for further development as supplements for preventing cancer or cardiovascular disease. Safety concerns of flavonoid/polyphenol supplements are also reviewed.

Peroxidative metabolism of apigenin and naringenin versus luteolin and quercetin: glutathione oxidation and conjugation

GSH was readily depleted by a flavonoid, H(2)O(2), and peroxidase mixture but the products formed were dependent on the redox potential of the flavonoid. Catalytic amounts of apigenin and naringenin but not kaempferol (flavonoids that contain a phenol B ring) when oxidized by H(2)O(2) and peroxidase co-oxidized GSH to GSSG via a thiyl radical which could be trapped by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) to form a DMPO-glutathionyl radical adduct detected by ESR spectroscopy. On the other hand, quercetin and luteolin (flavonoids that contain a catechol B ring) or kaempferol depleted GSH stoichiometrically without forming a thiyl radical or GSSG. Quercetin, luteolin, and kaempferol formed mono-GSH and bis-GSH conjugates, whereas apigenin and naringenin did not form GSH conjugates. MS/MS electrospray spectroscopy showed that mono-GSH conjugates for quercetin and luteolin had peaks at m/z 608 [M + H](+) and m/z 592 [M + H](+) in the positive-ion mode, respectively. (1)H NMR spectroscopy showed that the GSH was bound to the quercetin A ring. Spectral studies indicated that at a physiological pH the luteolin-SG conjugate was formed from a product with a UV maximum absorbance at 260 nm that was reducible by potassium borohydride. The quercetin-SG conjugate or kaempferol-SG conjugate on the other hand was formed from a product with a UV maximum absorbance at 335 nm that was not reducible by potassium borohydride. These results suggest that GSH was oxidized by apigenin/naringenin phenoxyl radicals, whereas GSH conjugate formation involved the o-quinone metabolite of luteolin or the quinoid (quinone methide) product of quercetin/kaempferol.

N-(4-hydroxyphenyl)retinamide induces apoptosis in T lymphoma and T lymphoblastoid leukemia cells

We demonstrate that N-(4-hydroxyphenyl)-all-trans-retinamide (4-HPR), a synthetic retinoic acid (RA) derivative, is a potent and selective inducer of apoptosis in malignant T lymphoid cells, but has little effect on normal lymphoid cells of the thymus or spleen. 4-HPR and its stereoisomer, 9-cis-4-HPR, are 50 to > 150 times more potent than 7 other retinoids in killing CEM-C7 human T lymphoblastoid leukemia cells and P1798-C7 murine T lymphoma cells. 4-HPR's apoptotic action requires the intact molecule bearing both the retinoid moiety and the hydroxyphenol ring; 4-HPR remains unmetabolized after uptake into CEM-C7 and P1798-C7 cells for up to 24 hours. We also show that glucocorticoid (GC)-resistant variants are equally susceptible to 4-HPR as are GC-sensitive cells. Thus, 4-HPR may be potentially important as a new chemotherapeutic drug for use as alternative to, or in combination with, conventional drugs for treating lymphoid malignancies.

N-(4-hydroxyphenyl)retinamide prevents development of T-lymphomas in AKR/J mice

N-(4-Hydroxyphenyl)retinamide (4-HPR), a synthetic retinoic acid derivative, has chemopreventive effects on several types of cancer. We recently showed that 4-HPR is a potent inducer of apoptosis in malignant, but not normal, T-lymphoid cells in vitro. To test 4-HPR's effect in vivo, we used the virus-induced T-lymphoma in AKR/J mice as a model system. The AKR/J mice were fed 4-HPR at 0, 1 or 2 mmole/kg diet, and the animals were monitored as to tumor development, plasma level of 4-HPR, body weight, appetite, and general health. Our results show that in a 19-week period, 4-HPR prevented T-lymphoma development by 40% and 50% of animals fed 1 and 2 mmole 4-HPR/ kg diet, respectively. In the plasma, 4-HPR reached micromolar levels without causing any observable deleterious side-effects. Thus, 4-HPR is potentially useful in chemoprevention of lymphoid cancers.

Dropping out from child psychiatric treatment: reasons and outcome

This study explores the reasons underlying dropping out from a child psychiatric clinic in Hong Kong, and the outcome of these children. A reluctance to accept psychiatric help, or the possibility of being labelled as psychiatrically ill, and differences between the families and doctors in their perception of the presenting problems are common reasons given for dropping out. A substantial number of children who dropped out continued to have some degree of psychiatric morbidity two years later. These results highlight the need to increase the community's awareness of the nature of child psychiatry, and for doctors to be sensitive to the families' perception of the presenting problems so as to minimise the likelihood of dropping out.

Immortalization of differentiated human keratinocytes by human papillomavirus (HPV) 16 DNA

Human papillomavirus (HPV) 16 is strongly implicated as having an etiologic role in cervical carcinoma. Human basal keratinocytes have been used in most HPV transformation studies, and transformed cells have exhibited undifferentiated characteristics. However, tumor cells in cervical squamous cell carcinoma are differentiated to certain degrees. Therefore, we hypothesize that HPV may transform not only basal cells but also differentiated keratinocytes. Human keratinocytes isolated from neonatal foreskin were induced to differentiate by treatment with 2 mM Ca2+ for various times (24, 48, 72 and 96 h) and were transfected with HPV 16 DNA. After G418 selection and repeated subculture, HPV 16-transformed cells were derived from each group of the Ca(2+)-treated and untreated cells. HPV DNA was detected in the transformed cells by polymerase chain reaction (PCR). Southern analysis and two-dimensional gel results indicated that HPV 16 DNA had been integrated into the chromosomes. The HPV 16-transformed cells exhibited an indefinite lifespan and were not tumorigenic in nude mice. They also showed the morphology and expressed the markers of differentiated keratinocytes. This study showed that differentiated human keratinocytes could be immortalized by HPV 16, and this may be a better model for cervical carcinomas in humans.

Cloning of mucosal and cutaneous HPV sequences in a metastatic squamous cell carcinoma from an epidermodysplasia verruciformis patient

Human papillomavirus (HPV) is a DNA tumor virus strongly associated with cervical neoplasias. There are over 80 different types of HPVs which can infect either mucosal or cutaneous tissue. Cutaneous squamous cell carcinomas (SCC) associated with HPV are often seen in patients with epidermodysplasia verruciformis (EV). EV is characterized by cutaneous lesions that progress to SCC upon UV exposure. In characterizing the HPV types associated with an unusually aggressive form of EV, we have cloned an HPV with homology to the moderately oncogenic genital type HPV 34, the oncogenic EV type HPV 5 and from benign oral mucosal type HPV 32. The presence of sequences from these highly divergent types is a novel finding. These three viral types are from different phylogenetic branches of the HPV family believed to have evolved independently from each other.

Deoxyadenosine blockade of G0 to G1 transition in lymphocytes: possible involvement of protein kinases

Immunodeficiency in adenosine deaminase deficiency has been attributed to the lymphotoxicity of deoxyadenosine that accumulates to high levels in patients. To gain insight into the mechanism of deoxyadenosine toxicity, we investigated the dose-response and time course of its toxic effects on concanavalin A-stimulated mouse splenic lymphocytes by thymidine incorporation and flow cytometry. Deoxyadenosine at a level as low as 0.3 microM inhibited the progression of G0. In contrast, higher concentrations of the nucleoside, i.e., in the range of 1 to 3 microM, were needed to block transition of the stimulated lymphocytes from G0 to G1. The inhibition of their S entry and progression required even higher concentrations. Furthermore, staurosporine, a potent inhibitor of protein kinases, was found to potentiate the toxicity of deoxyadenosine in mitogen-stimulated lymphocytes. Calcium mobilization in mitogen-activated lymphocytes was inhibited by deoxyadenosine. Our data suggest that, while ribonucleotide reductase inhibition by dATP could explain the blockade of S entry and progression by deoxyadenosine in cycling lymphocytes or leukemic cells, more important effects of this compound on antigen-activated lymphocytes occur at the early G0 phase. A possible mechanism of deoxyadenosine lethality is its inhibition of protein phosphorylation.

Mouse preproendothelin-1 gene. cDNA cloning, sequence analysis and determination of sites of expression during embryonic development

Endothelin-1 (ET-1) is a peptide implicated in a wide variety of functions involving vascular and non-vascular systems. We have cloned the cDNA encoding the mouse prepro-endothelin-1 (PPET-1) and determined its nucleotide sequence. The putative PPET-1 peptide processing sites are all conserved and the deduced 21-amino-acid mature ET-1 peptide is identical to that of the rat, human, bovine, porcine and rabbit. Using the cloned cDNA as a probe for in situ hybridization, we detected PPET-1 mRNA in different tissues at different stages of mouse embryonic development. Embryos at a stage as early as 9.5 days postcoitum (E9.5) have very strong expression in the branchial epithelium, optic vesicle and the endothelial cells of large blood vessels, including the dorsal aorta and aortic arches. While the expression level in the branchial epithelium was decreasing towards the later stage of embryogenesis, the expression in the endothelial cells increased with age. At E10.5, PPET-1 mRNA was also detected in the otic vesicle as well as in the developing gut epithelium. At later stage of development, the expression of PPET-1 was primarily found in the vascular endothelial cells, cochlea, eye and the gut, with the highest level of PPET-1 mRNA in the endothelial cells of the lung. These data will be useful for analyzing the function of ET-1 in these organs.