Hepatitis C Virus Seroprevalence in Persons Who Inject Drugs in Korea, 2012-2022: A Multicenter, Retrospective Study.

BACKGROUND: Limited data are available on hepatitis C virus (HCV) infection in persons who inject drugs (PWID) in South Korea. The present study aimed to investigate the seroprevalence of HCV antibodies, risk factors for HCV seropositivity, and HCV treatment status in PWID between January 2012 and May 2022. METHODS: We retrospectively reviewed the medical records of 418 drug users who underwent HCV antibody testing in three hospitals caring for 90% of known PWID in South Korea, of whom 373 were PWID. RESULTS: The HCV seroprevalence was 39.7% (148/373) in PWID vs. 6.7% (3/45) in non-injection drug users (P < 0.001). Age ≥ 40 years, hospital type (58.2% in the prison hospital vs. 34.0% in the private hospital), and enrollment year (68.2% in 2012-2014 vs. 30.0% in 2021-2022) were independently associated with HCV seropositivity. Among the HCV-seropositive PWID, 90.5% (134/148) were diagnosed with HCV infection; however, only 6.8% (10/148) received HCV treatment. The hepatitis B virus surface antigen and human immunodeficiency virus antibody positivity were 4.0% (14/352) and 1.9% (6/317) in tested PWID, respectively. CONCLUSION: The HCV seroprevalence in PWID was 39.7% with a very low treatment rate, which prompts active measures to test and treat PWID for HCV infection in South Korea.

Inhibition of Microsomal Prostaglandin E2 Synthase Reduces Collagen Deposition in Melanoma Tumors and May Improve Immunotherapy Efficacy by Reducing T-cell Exhaustion.

The arachidonic acid pathway participates in immunosuppression in various types of cancer. Our previous observation detailed that microsomal prostaglandin E2 synthase 1 (mPGES-1), an enzyme downstream of cyclooxygenase 2 (COX-2), limited antitumor immunity in melanoma; in addition, genetic depletion of mPGES-1 specifically enhanced immune checkpoint blockade therapy. The current study set out to distinguish the roles of mPGES-1 from those of COX-2 in tumor immunity and determine the potential of mPGES-1 inhibitors for reinforcing immunotherapy in melanoma. Genetic deletion of mPGES-1 showed different profiles of prostaglandin metabolites from that of COX-2 deletion. In our syngeneic mouse model, mPGES-1-deficient cells exhibited similar tumorigenicity to that of COX-2-deficient cells, despite a lower ability to suppress PGE2 synthesis by mPGES-1 depletion, indicating the presence of factors other than PGE2 that are likely to regulate tumor immunity. RNA-sequencing analysis revealed that mPGES-1 depletion reduced the expressions of collagen-related genes, which have been found to be associated with immunosuppressive signatures. In our mouse model, collagen was reduced in mPGES-1-deficient tumors, and phenotypic analysis of tumor-infiltrating lymphocytes indicated that mPGES-1-deficient tumors had fewer TIM3+ exhausted CD8+ T cells compared with COX-2-deficient tumors. CAY10678, an mPGES-1 inhibitor, was equivalent to celecoxib, a selective COX-2 inhibitor, in reinforcing anti-PD-1 treatment. Our study indicates that mPGES-1 inhibitors represent a promising adjuvant for immunotherapies in melanoma by reducing collagen deposition and T-cell exhaustion. Significance: Collagen is a predominant component of the extracellular matrix that may influence the tumor immune microenvironment for cancer progression. We present here that mPGES-1 has specific roles in regulating tumor immunity, associated with several collagen-related genes and propose that pharmacologic inhibition of mPGES-1 may hold therapeutic promise for improving immune checkpoint-based therapies.

Circulating microRNA miR-137 as a stable biomarker for methamphetamine abstinence.

OBJECTIVE: Stimulant use instigates abstinence syndrome in humans. miRNAs are a critical component for the pathophysiology of stimulant abstinence. Here we sought to identify a miRNA marker of methamphetamine abstinence in the circulating extracellular vesicles (cEVs). METHODS: miR-137 in the cEVs was quantified by qPCR in thirty-seven patients under methamphetamine abstinence and thirty-five age-matched healthy controls recruited from 2014 to 2016 from the general adult population in a hospital setting, Seoul, South Korea. Diagnostic power was evaluated by area under curve in the receiver-operating characteristics curve and other multiple statistical parameters. RESULTS: Patients under methamphetamine abstinence exhibited a significant reduction in cEV miR-137. Overall, cEV miR-137 had high potential as a blood-based marker of methamphetamine abstinence. cEV miR-137 retained the diagnostic power irrespective of the duration of methamphetamine abstinence or methamphetamine use. Interestingly, cEV miR-137 interacted with age: Control participants displayed an aging-dependent reduction of cEV miR-137, while methamphetamine-abstinent patients showed an aging-dependent increase in cEV miR-137. Accordingly, cEV miR-137 had variable diagnostic power depending on age, in which cEV miR-137 more effectively discriminated methamphetamine abstinence in the younger population. Duration of methamphetamine use or abstinence, cigarette smoking status, depressive disorder, or antidepressant treatment did not interact with the methamphetamine abstinence-induced reduction of cEV miR-137. CONCLUSION: Our data collectively demonstrated that miR-137 in the circulating extracellular vesicles held high potential as a stable and accurate diagnostic marker of methamphetamine abstinence syndrome.

Interplay between soluble CD74 and macrophage-migration inhibitory factor drives tumor growth and influences patient survival in melanoma.

Soluble forms of receptors play distinctive roles in modulating signal-transduction pathways. Soluble CD74 (sCD74) has been identified in sera of inflammatory diseases and implicated in their pathophysiology; however, few relevant data are available in the context of cancer. Here we assessed the composition and production mechanisms, as well as the clinical significance and biological properties, of sCD74 in melanoma. Serum sCD74 levels were significantly elevated in advanced melanoma patients compared with normal healthy donors, and the high ratio of sCD74 to macrophage-migration inhibitory factor (MIF) conferred significant predictive value for prolonged survival in these patients (p = 0.0035). Secretion of sCD74 was observed primarily in melanoma cell lines as well as a THP-1 line of macrophages from monocytes and primary macrophages, especially in response to interferon-γ (IFN-γ). A predominant form that showed clinical relevance was the 25-KDa sCD74, which originated from the 33-KDa isoform of CD74. The release of this sCD74 was regulated by either a disintegrin and metalloproteinase-mediated cell-surface cleavage or cysteine-protease-mediated lysosomal cleavage, depending on cell types. Both recombinant and THP-1 macrophage-released endogenous sCD74 suppressed melanoma cell growth and induced apoptosis under IFN-γ stimulatory conditions via inhibiting the MIF/CD74/AKT-survival pathway. Our findings demonstrate that the interplay between sCD74 and MIF regulates tumor progression and determines patient outcomes in advanced melanoma.

JNK1/2 represses Lkb1-deficiency-induced lung squamous cell carcinoma progression.

Mechanisms of lung squamous cell carcinoma (LSCC) development are poorly understood. Here, we report that JNK1/2 activities attenuate Lkb1-deficiency-driven LSCC initiation and progression through repressing ΔNp63 signaling. In vivo Lkb1 ablation alone is sufficient to induce LSCC development by reducing MKK7 levels and JNK1/2 activities, independent of the AMPKα and mTOR pathways. JNK1/2 activities is positively regulated by MKK7 during LSCC development. Pharmaceutically elevated JNK1/2 activities abates Lkb1 dependent LSCC formation while compound mutations of Jnk1/2 and Lkb1 further accelerate LSCC progression. JNK1/2 is inactivated in a substantial proportion of human LSCC and JNK1/2 activities positively correlates with survival rates of lung, cervical and head and neck squamous cell carcinoma patients. These findings not only determine a suppressive role of the stress response regulators JNK1/2 on LSCC development by acting downstream of the key LSCC suppresser Lkb1, but also demonstrate activating JNK1/2 activities as a therapeutic approach against LSCC.

The COX2 Effector Microsomal PGE2 Synthase 1 is a Regulator of Immunosuppression in Cutaneous Melanoma.

PURPOSE: Microsomal prostaglandin E2 synthase 1 (mPGES1) was evaluated as an important downstream effector of the COX2 pathway responsible for tumor-mediated immunosuppression in melanoma. EXPERIMENTAL DESIGN: The analysis of a stage III melanoma tissue microarray (n = 91) was performed to assess the association between mPGES1, COX2, CD8, and patient survival. Pharmacologic inhibitors and syngeneic mouse models using PTGES-knockout (KO) mouse melanoma cell lines were used to evaluate the mPGES1-mediated immunosuppressive function. RESULTS: We observed correlations in expression and colocalization of COX2 and mPGES1, which are associated with increased expression of immunosuppressive markers in human melanoma. In a syngeneic melanoma mouse model, PTGES KO increased melanoma expression of PD-L1, increased infiltration of CD8a+ T cells, and CD8a+ dendritic cells into tumors and suppressed tumor growth. Durable tumor regression was observed in mice bearing PTGES KO tumors that were given anti-PD-1 therapy. Analysis of a stage III melanoma tissue microarray revealed significant associations between high mPGES1 expression and low CD8+ infiltration, which correlated with a shorter patient survival. CONCLUSIONS: Our results are the first to illustrate a potential role for mPGES1 inhibition in melanoma immune evasion and selective targeting in supporting the durability of response to PD-1 checkpoint immunotherapy. More research effort in this drug development space is needed to validate the use of mPGES1 inhibitors as safe treatment options.

IL17A Regulates Tumor Latency and Metastasis in Lung Adeno and Squamous SQ.2b and AD.1 Cancer.

Somatic mutations can promote malignant transformation of airway epithelial cells and induce inflammatory responses directed against resultant tumors. Tumor-infiltrating T lymphocytes (TIL) in early-stage non-small cell lung cancer (NSCLC) secrete distinct proinflammatory cytokines, but the contribution of these TILs to tumor development and metastasis remains unknown. We show here that TILs in early-stage NSCLC are biased toward IL17A expression (Th17) when compared with adjacent tumor-free tissue, whereas Th17 cells are decreased in tumor infiltrating locoregional lymph nodes in advanced NSCLC. Mice in which Pten and Smad4 (Pts4d/d ) are deleted from airway epithelial cells develop spontaneous tumors, that share genetic signatures with squamous- (SQ.2b), and adeno- (AD.1) subtypes of human NSCLC. Pts4d/d mice globally lacking in IL17a (Pts4d/dIl17a-/- ) showed decreased tumor latency and increased metastasis. Th17 cells were required for recruitment of CD103+ dendritic cells, and adoptive transfer of IL17a-sufficient CD4+ T cells reversed early tumor development and metastasis in Pts4d/dIl17a-/- mice. Together, these findings support a key role for Th17 cells in TILs associated with the Pts4d/d model of NSCLC and suggest therapeutic and biomarker strategies for human SQ2b and AD1 lung cancer. Cancer Immunol Res; 6(6); 645-57. ©2018 AACR.

Mig-6 deficiency cooperates with oncogenic Kras to promote mouse lung tumorigenesis.

OBJECTIVES: Lung cancer is the leading cause of cancer related deaths worldwide and mutation activating KRAS is one of the most frequent mutations found in lung adenocarcinoma. Identifying regulators of KRAS may aid in the development of therapies to treat this disease. The mitogen-induced gene 6, MIG-6, is a small adaptor protein modulating signaling in cells to regulate the growth and differentiation in multiple tissues. Here, we investigated the role of Mig-6 in regulating adenocarcinoma progression in the lungs of genetically engineered mice with activation of Kras. MATERIALS AND METHODS: Using the CCSPCre mouse to specifically activate expression of the oncogenic KrasG12D in Club cells, we investigated the expression of Mig-6 in CCSPCreKrasG12D-induced lung tumors. To determine the role of Mig-6 in KrasG12D-induced lung tumorigenesis, Mig-6 was conditionally ablated in the Club cells by breeding Mig6f/f mice to CCSPCreKrasG12D mice, yielding CCSPCreMig-6d/dKrasG12D mice (Mig-6d/dKrasG12D). RESULTS: We found that Mig-6 expression is decreased in CCSPCreKrasG12D-induced lung tumors. Ablation of Mig-6 in the KrasG12D background led to enhanced tumorigenesis and reduced life expectancy. During tumor progression, there was increased airway hyperplasia, a heightened inflammatory response, reduced apoptosis in KrasG12D mouse lungs, and an increase of total and phosphorylated ERBB4 protein levels. Mechanistically, Mig-6 deficiency attenuates the cell apoptosis of lung tumor expressing KRASG12D partially through activating the ErbB4 pathway. CONCLUSIONS: In summary, Mig-6 deficiency promotes the development of KrasG12D-induced lung adenoma through reducing the cell apoptosis in KrasG12D mouse lungs partially by activating the ErbB4 pathway.

Krüppel-Like Factor 12 Promotes Colorectal Cancer Growth through Early Growth Response Protein 1.

Krüppel-like factor 12 (KLF12) is a transcription factor that plays a role in normal kidney development and repression of decidualization. KLF12 is frequently elevated in esophageal adenocarcinoma and has been reported to promote gastric cancer progression. Here, we examined the role of KLF12 in colorectal cancer (CRC). Indeed, KLF12 promotes tumor growth by directly activating early growth response protein 1 (EGR1). The levels of KLF12 and EGR1 correlate synergistically with a poor prognosis. These results indicate that KLF12 likely plays an important role in CRC and could serve as a potential prognostic marker and therapeutic target.

Microsomal PGE2 synthase-1 regulates melanoma cell survival and associates with melanoma disease progression.

COX-2 and its product PGE2 enhance carcinogenesis and tumor progression, which has been previously reported in melanoma. As most COX inhibitors cause much toxicity, the downstream microsomal PGE2 synthase-1 (mPGES1) is a consideration for targeting. Human melanoma TMAs were employed for testing mPGES1 protein staining intensity and percentage levels, and both increased with clinical stage; employing a different Stage III TMA, mPGES1 intensity (not percentage) associated with reduced patient survival. Our results further show that iNOS was also highly expressed in melanoma tissues with high mPGES1 levels, and iNOS-mediated NO promoted mPGES1 expression and PGE2 production. An mPGES1-specific inhibitor (CAY10526) as well as siRNA attenuated cell survival and increased apoptosis. CAY10526 significantly suppressed tumor growth and increased apoptosis in melanoma xenografts. Our findings support the value of a prognostic and predictive role for mPGES1, and suggest targeting this molecule in the PGE2 pathway as another avenue toward improving melanoma therapy.

ErbB2 Pathway Activation upon Smad4 Loss Promotes Lung Tumor Growth and Metastasis.

Lung cancer remains the leading cause of cancer death. Genome sequencing of lung tumors from patients with squamous cell carcinoma has identified SMAD4 to be frequently mutated. Here, we use a mouse model to determine the molecular mechanisms by which Smad4 loss leads to lung cancer progression. Mice with ablation of Pten and Smad4 in airway epithelium develop metastatic adenosquamous tumors. Comparative transcriptomic and in vivo cistromic analyses determine that loss of PTEN and SMAD4 results in ELF3 and ErbB2 pathway activation due to decreased expression of ERRFI1, a negative regulator of ERBB2 in mouse and human cells. The combinatorial inhibition of ErbB2 and Akt signaling attenuate tumor progression and cell invasion, respectively. Expression profile analysis of human lung tumors substantiated the importance of the ErbB2/Akt/ELF3 signaling pathway as both a prognostic biomarker and a therapeutic drug target for treating lung cancer.

Uterine-specific loss of Tsc2 leads to myometrial tumors in both the uterus and lungs.

Lymphangioleiomyomatosis (LAM) is a rare disease characterized by proliferation of abnormal smooth-muscle cells in the lungs, leading to functional loss and sometimes lung transplantation. Although the origin of LAM cells is unknown, several features of LAM provide clues. First, LAM cells contain inactivating mutations in genes encoding Tsc1 or Tsc2, proteins that limit mTORC1 activity. Second, LAM tumors recur after lung transplantation, suggesting a metastatic pathogenesis. Third, LAM is found almost exclusively in women. Finally, LAM shares features with uterine leiomyomas, benign tumors of myometrial cells. From these observations, we proposed that LAM cells might originate from uterine leiomyomas containing Tsc mutations. To test our hypothesis, and to develop mouse models for leiomyoma and LAM, we targeted Tsc2 deletion primarily in uterine cells. In fact, nearly 100% of uteri from uterine-specific Tsc2 knockout mice developed myometrial proliferation and uterine leiomyomas by 12 and 24 weeks, respectively. Myometrial proliferation and mTORC1/S6 activity were abrogated by the mTORC1 inhibitor rapamycin or by elimination of sex steroid production through ovariectomy or aromatase inhibition. In ovariectomized Tsc2 null mice, mTORC1/S6 activity and myometrial growth were restored by estrogen but not progesterone. Thus, even without Tsc2, estrogen appears to be required for myometrial mTORC1/S6 signaling and proliferation. Finally, we found Tsc2 null myometrial tumors in lungs of older Tsc2 uterine-specific knockout females, suggesting that lung LAM-like myometrial lesions may indeed originate from the uterus. This mouse model may improve our understanding of LAM and leiomyomas and might lead to novel therapeutic strategies for both diseases.

Critical tumor suppressor function mediated by epithelial Mig-6 in endometrial cancer.

Endometrial cancer is preceded by endometrial hyperplasia, unopposed estrogen exposure, and genetic alterations, but the precise causes of endometrial cancer remain uncertain. Mig-6, mainly known as a negative regulator of the EGF receptor, is an important mediator of progesterone signaling in the uterus, where it mediates tumor suppression by modulating endometrial stromal-epithelial communications. In this study, we investigated the function of Mig-6 in the uterine epithelium using a tissue-specific gene knockout strategy, in which floxed Mig-6 (Mig-6(f/f)) mice were crossed to Wnt7a-Cre mice (Wnt7a(cre+)Mig-6(f/f)). Wnt7a(cre+)Mig-6(f/f) mice developed endometrial hyperplasia and estrogen-dependent endometrial cancer, exhibiting increased proliferation in epithelial cells as well as apoptosis in subepithelial stromal cells. We documented increased expression of NOTCH1 and BIRC3 in epithelial cells of Wnt7a(cre+)Mig-6(f/f) mice and decreased expression of the progesterone receptor (PR) in stromal cells. Progesterone therapy controls endometrial growth and prevents endometrial cancer, but the effectiveness of progesterone as a treatment for women with endometrial cancer is less clear. We noted that the hyperplasic phenotype of Wnt7a(cre+)Mig-6(f/f) mice was prevented by progesterone treatment, whereas this treatment had no effect in PR(cre/+)Mig-6(f/f) mice where Mig-6 was deleted in both the epithelial and stromal compartments of the uterus. In contrast, activation of progesterone signaling in the stroma regulated proliferation and apoptosis in the epithelium via suppression of ERα signaling. In summary, our results establish that epithelial Mig-6 functions as a critical tumor suppressor that mediates the ability of progesterone to prevent the development of endometrial cancer.

The BTBD9 gene may be associated with antipsychotic-induced restless legs syndrome in schizophrenia.

OBJECTIVE: A genome-wide association study and several replication studies have shown significant association between BTBD9 gene single nucleotide polymorphisms and restless legs syndrome (RLS). The aim of this study is to investigate the association between the BTBD9 gene polymorphisms and antipsychotic-induced RLS in schizophrenic patients. METHODS: Restless legs syndrome symptoms were evaluated using the diagnostic criteria of the International Restless Legs Syndrome Study Group in 190 Korean schizophrenic patients. We genotyped the rs9357271 and rs3923809 polymorphisms of the BTBD9 gene in schizophrenic patients with (n = 96) and without (n = 94) RLS symptoms. RESULTS: There was a significant difference in the allele frequency (χ(2) = 8.14, p = 0.004) of the rs9357271 polymorphism between schizophrenic patients with and without RLS symptoms. Significant genotypic association of this single nucleotide polymorphisms with RLS symptoms was also observed for the dominant model (χ(2) = 10.32, p = 0.001) and heterozygous model (χ(2) = 10.9, p = 0.001). When we compared the frequencies of the rs3923809-rs9357271 haplotypes between the two groups, the overall haplotype frequencies were significantly different (permuted p = 0.037), and the A-T haplotype was significantly more frequent in the RLS symptom group than in the no RLS symptom group (0.112 vs. 0.041, permuted p = 0.007). CONCLUSIONS: These data suggest that the BTBD9 gene is associated with antipsychotic-induced RLS symptoms in schizophrenic patients.

There is no evidence for an association between the serotonin receptor 3A gene C178T polymorphism and tardive dyskinesia in Korean schizophrenia patients.

BACKGROUND: Tardive dyskinesia (TD) is a potential adverse effect of long-term treatment with antipsychotics. Previous studies have suggested a link between brain serotonergic systems and TD vulnerability. A recent report described that a serotonin 3 receptor (5-HTR3) agonist induced rhythmic movements in mice with complete paraplegia. Furthermore, it has been reported that the 5-HTR3 antagonist ondansetron is efficacious in the treatment of Gilles de la Tourette syndrome (GTS). AIM: The aim of the present study was to determine whether the 5-HTR3A gene C178T polymorphism is associated with antipsychotic-induced TD in Korean schizophrenia patients. METHODS: We investigated 280 Korean schizophrenia patients. Subjects with TD (n = 105) and without TD (n = 175) were matched for antipsychotic drug exposure and other relevant variables. RESULTS: The distributions of genotypic (chi-squared = 3.55, p = 0.169) and allelic (chi-squared = 0.40, p = 0.528) frequencies did not differ between patients with and without TD. The total score on the Abnormal Involuntary Movement Scale also did not differ between the two genotype groups (F = 0.94, p = 0.391). CONCLUSIONS: The findings of the present study do not support the involvement of the 5-HTR3A gene C178T polymorphism in TD in Korean schizophrenia subjects.

Decreased cortical complexity in methamphetamine abusers.

This study aimed to investigate if methamphetamine (MA) abusers exhibit alterations in complexity of the electroencephalogram (EEG) and to determine if these possible alterations are associated with their abuse patterns. EEGs were recorded from 48 former MA-dependent males and 20 age- and sex-matched healthy subjects. Approximate Entropy (ApEn), an information-theoretical measure of irregularity, of the EEGs was estimated to quantify the degree of cortical complexity. The ApEn values in MA abusers were significantly lower than those of healthy subjects in most of the cortical regions, indicating decreased cortical complexity of MA abusers, which may be associated with impairment in specialization and integration of cortical activities owing to MA abuse. Moreover, ApEn values exhibited significant correlations with the clinical factors including abuse patterns, symptoms of psychoses, and their concurrent drinking and smoking habits. These findings provide insights into abnormal information processing in MA abusers and suggest that ApEn of EEG recordings may be used as a potential supplementary tool for quantitative diagnosis of MA abuse. This is the first investigation to assess the "severity-dependent dynamical complexity" of EEG patterns in former MA abusers and their associations with the subjects' abuse patterns and other clinical measures.

Association study between antipsychotic-induced restless legs syndrome and polymorphisms of monoamine oxidase genes in schizophrenia.

OBJECTIVE: This study aimed to investigate whether the monoamine oxidase (MAO) A and B genes are associated with antipsychotic-induced restless legs syndrome (RLS) in schizophrenia. METHODS: We assessed antipsychotic-induced RLS symptoms in 190 Korean schizophrenic patients and divided the subjects into two groups: those with RLS symptoms (n = 96) and those without RLS symptoms (n = 94). Genotyping was performed for the variable number of tandem repeat (VNTR) polymorphism of the MAOA gene and A644G polymorphism of the MAOB gene. RESULTS: There was no significant difference in the genotype and allele frequencies of all polymorphisms investigated between these two groups. However, the result of global haplotype analysis showed a significant difference in haplotype frequencies between male subjects with and without RLS symptoms (p = 0.013). The interaction between two polymorphisms had a significant effect on the RLS scores of both male (p = 0.047) and female (p = 0.028) patients. CONCLUSIONS: These data do not suggest that the MAOA gene VNTR and MAOB gene A644G polymorphisms are associated with antipsychotic-induced RLS symptoms in schizophrenia. However, we found that the haplotype frequencies differed between the male schizophrenic patients with and without RLS symptom and the interaction between the two polymorphisms had a significant influence on the RLS scores of patients with schizophrenia.

In vivo evidence for long-term CNS toxicity, associated with chronic binge use of methamphetamine.

OBJECTIVE: The aim of this study was to examine disturbances in regional cerebral blood flow (rCBF) associated with methamphetamine abuse. METHODS: Using Single Photon Emission Computed Tomography (SPECT), rCBF was measured in 20 men who had previously injected methamphetamine intravenously for over 30 months and who were now abstinent for a minimum of 9 months and for an average of 2 years. Values were compared with those in 12 healthy men who had never injected methamphetamine. RESULTS: While rCBF was significantly and disproportionately reduced in subcortical and dorsal cortical brain regions, including the striatum, thalamus, cingulum, mesiodorsal prefrontal cortex, and pons (all t's>8.3 after global normalization, corrected p's<0.001), whole brain CBF was also significantly reduced in the former methamphetamine users. Binge use of methamphetamine is associated with long-term changes in both global and regional blood flows, likely representing severe and enduring neural toxicity of monoaminergic neurotransmitter systems in the brain, producing a pattern of hypoperfusion that resembles patterns reported previously for persons with atypical Parkinson's disease. CONCLUSIONS: These findings suggest that methamphetamine abusers may be possibly at increased risk for neurodegenerative diseases later in life.

Mig-6 is required for appropriate lung development and to ensure normal adult lung homeostasis.

Mitogen-inducible gene 6 [Mig-6; Errfi1 (ErbB receptor feedback inhibitor 1); RALT (receptor-associated late transducer); gene 33] is a ubiquitously expressed adaptor protein containing CRIB, SH3 and 14-3-3 interacting domains and has been shown to negatively regulate EGF signaling. Ablation of Mig-6 results in a partial lethal phenotype in which surviving mice acquire degenerative joint diseases and tumors in multiple organs. We have determined that the early lethality in Mig-6(-/-) mice occurs in the perinatal period, with mice displaying abnormal lung development. Histological examination of Mig-6(-/-) lungs (E15.5-P3) revealed reduced septation, airway over-branching, alveolar type II cell hyperplasia, and disturbed vascular formation. In neonatal Mig-6(-/-) lungs, cell proliferation increased in the airway epithelium but apoptosis increased in the blood vessels. Adult Mig-6(-/-) mice developed features of chronic obstructive pulmonary disease (COPD); however, when Mig-6 was inducibly ablated in adult mice (Mig-6(d/d)), the lungs were normal. Knockdown of MIG-6 in H441 human bronchiolar epithelial cells increased phospho-EGFR and phospho-AKT levels as well as cell proliferation, whereas knockdown of MIG-6 in human lung microvascular endothelial (HMVEC-L) cells promoted their apoptosis. These results demonstrate that Mig-6 is required for prenatal and perinatal lung development, in part through the regulation of EGF signaling, as well as for maintaining proper pulmonary vascularization.