Autoimmune cerebellar ataxia associated with anti-leucine-rich glioma-inactivated protein 1 antibodies: Two pediatric cases.

OBJECTIVES: To report two pediatric cases of autoimmune cerebellar ataxia associated with the anti-Leucine-rich glioma-inactivated protein 1 (LGI1)antibodies. METHODS: The clinical features of the two patients were described retrospectively. The indirect immunofluorescence using transfected cells (cell-based assay, CBA) and the rat cerebellum (tissue-based assay, TBA) with the multi-antigen co-plate biochip mosaic techniques were used to detect the antibodies. Clinical and laboratory characteristics were described. RESULTS: Two males were included. The onset ages were 2.7y and 4y, respectively. Patient 1 manifested as isolated acute cerebellar ataxia. Patient 2 had extra-cerebellar symptoms, including seizures, encephalopathy, faciobrachial dystonic seizures(FBDs), and significant cerebellar ataxia. The hyponatremia and tumors were not found. Both of them responded well to the immunotherapy. CONCLUSIONS: The autoimmune cerebellar ataxia might be a new phenotype of LGI1-Abs autoimmunity in children.

Pediatric anti-N-methyl-D-aspartate receptor encephalitis with MOG-Ab co-existence: Relapse propensity and treatability.

OBJECTIVES: To investigate the clinical characteristics of the anti-N-methyl-D-aspartate receptor(NMDAR)encephalitis with anti-myelin oligodendrocyte glycoprotein antibody(MOG-Ab)positivity serostatus in pediatric patients. METHODS: The clinical manifestations, treatments, and outcomes of patients with anti-NMDAR encephalitis with positive MOG-Ab were elaborated. The annualized relapse rates (ARRs) were compared before and during treatment with disease-modifying drugs (DMDs). RESULTS: Twelve patients were included. In the prospective cohort(Cohort A), MOG-Ab positivity was associated with relapse (p = 0.028, OR = 1.677). Eight cases relapsed, of which six cases were treated with DMDs. The median ARR reduced significantly following DMDs treatments (z = 1.992, P = 0.046). CONCLUSIONS: The anti-NMDAR encephalitis patients with MOG-Ab co-existence are prone to relapse. Long-term DMDs therapy can reduce ARRs.

PKCδ-mediated SGLT1 upregulation confers the acquired resistance of NSCLC to EGFR TKIs.

The tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) have been widely used for non-small cell lung cancer (NSCLC) patients, but the development of acquired resistance remains a therapeutic hurdle. The reduction of glucose uptake has been implicated in the anti-tumor activity of EGFR TKIs. In this study, the upregulation of the active sodium/glucose co-transporter 1 (SGLT1) was found to confer the development of acquired EGFR TKI resistance and was correlated with the poorer clinical outcome of the NSCLC patients who received EGFR TKI treatment. Blockade of SGLT1 overcame this resistance in vitro and in vivo by reducing glucose uptake in NSCLC cells. Mechanistically, SGLT1 protein was stabilized through the interaction with PKCδ-phosphorylated (Thr678) EGFR in the TKI-resistant cells. Our findings revealed that PKCδ/EGFR axis-dependent SGLT1 upregulation was a critical mechanism underlying the acquired resistance to EGFR TKIs. We suggest co-targeting PKCδ/SGLT1 as a potential strategy to improve the therapeutic efficacy of EGFR TKIs in NSCLC patients.

Rethink of EGFR in Cancer With Its Kinase Independent Function on Board.

The epidermal growth factor receptor (EGFR) is one of most potent oncogenes that are commonly altered in cancers. As a receptor tyrosine kinase, EGFR's kinase activity has been serving as the primary target for developing cancer therapeutics, namely the EGFR inhibitors including small molecules targeting its ATP binding pocket and monoclonal antibodies targeting its ligand binding domains. EGFR inhibitors have produced impressive therapeutic benefits to responsive types of cancers. However, acquired and innate resistances have precluded current anti-EGFR agents from offering sustainable benefits to initially responsive cancers and benefits to EGFR-positive cancers that are innately resistant. Recent years have witnessed a realization that EGFR possesses kinase-independent (KID) pro-survival functions in cancer cells. This new knowledge has offered a different angle of understanding of EGFR in cancer and opened a new avenue of targeting EGFR for cancer therapy. There are already many excellent reviews on the role of EGFR with a focus on its kinase-dependent functions and mechanisms of resistance to EGFR targeted therapies. The present opinion aims to initiate a fresh discussion about the function of EGFR in cancer cells by laying out some unanswered questions pertaining to EGFR in cancer cells, by rethinking the unmet therapeutic challenges from a view of EGFR's KID function, and by proposing novel approaches to target the KID functions of EGFR for cancer treatment.

Neurochondrin Antibody Serum Positivity in Three Cases of Autoimmune Cerebellar Ataxia.

To report three cases of autoimmune ataxia patients with positive neurochondrin (NCDN) antibodies. Patients with unknown cerebellar ataxia were screened for autoimmune cerebellar ataxia (ACA)-related antibodies, including glutamic acid decarboxylase 65 (GAD65), delta/notch-like epidermal growth factor-related receptor (Tr/DNER), zinc finger protein 4 (ZIC4), inositol 1,4,5-triphosphate receptor 1 (ITPR1), Homer protein homologue 3 (Homer-3), neurochondrin (NCDN), Purkinje cell antibody 2 (PCA-2) and carbonic anhydrase-related protein VII (CARPVII). The antibodies were assessed by indirect immunofluorescence using transfected cells (cell-based assay, CBA) and monkey cerebellum (tissue-based assay, TBA) with the multi-antigen co-plate biochip mosaic technique. Patients with positive antibodies received immunotherapy and were followed up in the clinic. Clinical characteristics, laboratory data, and outcomes of antibody-positive patients were described, analysed and compared with previously reported cases. The NCDN antibody was positive in three male patients in whom the onset ages were four years and 11 months, two years and seven months and 67 years old. Serum antibody titres were 1:32, 1:100 and 1:320. Cerebral ataxia was the most prominent presentation. Cerebellar atrophy was found in one of the patients. Immunotherapy was effective in all three patients. The NCDN antibody is associated with autoimmune ataxia, and it has been suggested that the NCDN antibody should be tested in patients with cerebellar ataxia who are negative for routine ACA antibodies. Early immunotherapy may have a beneficial impact on prognosis.

Kinase-Inactivated EGFR Is Required for the Survival of Wild-Type EGFR-Expressing Cancer Cells Treated with Tyrosine Kinase Inhibitors.

Inhibiting the tyrosine kinase activity of epidermal growth factor receptor (EGFR) using small molecule tyrosine kinase inhibitors (TKIs) is often ineffective in treating cancers harboring wild-type EGFR (wt-EGFR). TKIs are known to cause dimerization of EGFR without altering its expression level. Given the fact that EGFR possesses kinase-independent pro-survival function, the role of TKI-inactivated EGFR in cancer cell survival needs to be addressed. In this study, using wt-EGFR-expressing cancer cells A549 (lung), DU145 (prostate), PC3 (prostate), and MDA-MB-231 (breast), we characterized the TKI-induced dimerization status of EGFR and determined the dependency of cells on kinase-inactivated EGFR for survival. We report that TKI-induced EGFR dimerization is dependent on palmitoylation and independent of its kinase activity, and that mutations of the cysteine residues known to be critical for EGFR's palmitoylation abolished TKI-induced EGFR dimerization. Furthermore, TKI-induced EGFR dimerization is persistent in TKI-resistant cells, and inhibition of palmitoylation by 2-bromopalmitate, or targeted reduction of the kinase-inactivated EGFR by siRNA or by an EGFR-downregulating peptide, are lethal to TKI-resistant cancer cells. This study suggests that kinase-inactivated EGFR remains to be a viable therapeutic target for wt-EGFR cancers and that inhibiting palmitoylation or downregulating EGFR may overcome TKI resistance.

Targeted reduction of the EGFR protein, but not inhibition of its kinase activity, induces mitophagy and death of cancer cells through activation of mTORC2 and Akt.

The oncogenic epidermal growth factor receptor (EGFR) is commonly overexpressed in solid cancers. The tyrosine kinase activity of EGFR has been a major therapeutic target for cancer; however, the efficacy of EGFR tyrosine kinase inhibitors to treat cancers has been challenged by innate and acquired resistance at the clinic. Accumulating evidence suggests that EGFR possesses kinase-independent pro-survival functions, and that cancer cells are more vulnerable to reduction of EGFR protein than to inhibition of its kinase activity. The molecular mechanism underlying loss-of-EGFR-induced cell death remains largely unknown. In this study, we show that, unlike inhibiting EGFR kinase activity that is known to induce pro-survival non-selective autophagy, downregulating EGFR protein, either by siRNA, or by a synthetic EGFR-downregulating peptide (Herdegradin), kills prostate and ovarian cancer cells via selective mitophagy by activating the mTORC2/Akt axis. Furthermore, Herdegradin induced mitophagy and inhibited the growth of orthotopic ovarian cancers in mice. This study identifies anti-mitophagy as a kinase-independent function of EGFR, reveals a novel function of mTORC2/Akt axis in promoting mitophagy in cancer cells, and offers a novel approach for pharmacological downregulation of EGFR protein as a potential treatment for EGFR-positive cancers.

Estrogen receptor alpha is cell cycle-regulated and regulates the cell cycle in a ligand-dependent fashion.

Estrogen receptor alpha (ERα) has been implicated in several cell cycle regulatory events and is an important predictive marker of disease outcome in breast cancer patients. Here, we aimed to elucidate the mechanism through which ERα influences proliferation in breast cancer cells. Our results show that ERα protein is cell cycle-regulated in human breast cancer cells and that the presence of 17-ß-estradiol (E2) in the culture medium shortened the cell cycle significantly (by 4.5 hours, P < 0.05) compared with unliganded conditions. The alterations in cell cycle duration were observed in the S and G2/M phases, whereas the G1 phase was indistinguishable under liganded and unliganded conditions. In addition, ERα knockdown in MCF-7 cells accelerated mitotic exit, whereas transfection of ERα-negative MDA-MB-231 cells with exogenous ERα significantly shortened the S and G2/M phases (by 9.1 hours, P < 0.05) compared with parental cells. Finally, treatment of MCF-7 cells with antiestrogens revealed that tamoxifen yields a slower cell cycle progression through the S and G2/M phases than fulvestrant does, presumably because of the destabilizing effect of fulvestrant on ERα protein. Together, these results show that ERα modulates breast cancer cell proliferation by regulating events during the S and G2/M phases of the cell cycle in a ligand-dependent fashion. These results provide the rationale for an effective treatment strategy that includes a cell cycle inhibitor in combination with a drug that lowers estrogen levels, such as an aromatase inhibitor, and an antiestrogen that does not result in the degradation of ERα, such as tamoxifen.

Intracellular activation of EGFR by fatty acid synthase dependent palmitoylation.

Epidermal growth factor receptor (EGFR) is an oncogenic receptor tyrosine kinase. Canonically, the tyrosine kinase activity of EGFR is regulated by its extracellular ligands. However, ligand-independent activation of EGFR exists in certain cancer cells, and the underlying mechanism remains to be defined. In this study, using PC3 and A549 cells as a model, we have found that, in the absence of extracellular ligands, a subpopulation of EGFR is constitutively active, which is needed for maintaining cell proliferation. Furthermore, we have found that fatty acid synthase (FASN)-dependent palmitoylation of EGFR is required for EGFR dimerization and kinase activation. Inhibition of FASN or palmitoyl acyltransferases reduced the activity and down-regulated the levels of EGFR, and sensitized cancer cells to EGFR tyrosine kinase inhibitors. It is concluded that EGFR can be activated intracellularly by FASN-dependent palmitoylation. This mechanism may serve as a new target for improving EGFR-based cancer therapy.

[Clinical characteristics and follow-up of pediatric patients with neuromyelitis optica and neuromyelitis optica spectrum disorders].

OBJECTIVE: To analyze the clinical characteristics of pediatric neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD). METHOD: A retrospective analysis was performed evaluating clinical and laboratory characteristics of ten NMO and NMOSD children who were seen in our hospital from December 2010 to May 2014. Median age at onset was 8.9 years (range 0.8-13.8 years). Seven cases were female and three were male. Median disease duration was 1.5 months (range 1-18.5 months). RESULT: Eight patients fulfilled diagnostic criteria for NMO and two patients fulfilled diagnostic criteria for NMOSD. The two NMOSD patients had recurrent longitudinally extensive transverse myelitis. Four cases had a monophasic disease course, and six cases had a recurrent course. In eight NMO patients, neuritis was the initial presentation. The two NMOSD patients had no neuritis in the first attack. Nine cases had clinical manifestations of myelitis, one case had asymptomatic spinal cord MRI anomaly. Among the ten patients, seven cases had brain lesions, wherein, four cases had the midbrain involvement and in four cases extensive hemispheric white matter was involved. Three cases had medullary involvement. And two cases had posterior limb of the internal capsule involvement, two cases had thalamus involvement. In one case there was pons, cerebellum or corpus callosum involvement, respectively. One case had accompanied brain symptoms. Of the five patients who had symptomatic brain lesions, four cases had encephalopathy accompanied by large hemispheric lesions on MRI, having a presentation similar to acute disseminated encephalomyelitis. And one case had multiple sclerosis like brain lesion. Of the ten patients tested, nine were seropositive for anti-aquaporin-4 autoantibody. One-patient was complicated with systemic lupus erythematosus. Oligoclonal bands were negative in all cases. All patients received treatment for acute attacks with high-dose intravenous methylprednisolone and intravenous gammaglobulin. The symptoms of 8 cases mitigated. Two cases whose symptoms showed no sign of improvement received plasmapheresis for acute attacks. Seven of the patients were followed up. The median duration of follow-up was 19 months (ranged from 13 months to 30 months). The median Expanded disability status (EDSS) score was 3 (range 1-7). CONCLUSION: Pediatric NMO and(or) NMOSD have a diverse clinical presentation which are more than just optic neuritis and transverse myelitis, including brain symptom. So it may be difficult to distinguish NMO and( or) NMOSD from acute disseminating encephalomyelitis and multiple sclerosis in the early stages of the disease. Antibodies to aquapoin-4 (AQP-Ab) testing is very important for differential diagnosis.

Gain of glucose-independent growth upon metastasis of breast cancer cells to the brain.

Breast cancer brain metastasis is resistant to therapy and a particularly poor prognostic feature in patient survival. Altered metabolism is a common feature of cancer cells, but little is known as to what metabolic changes benefit breast cancer brain metastases. We found that brain metastatic breast cancer cells evolved the ability to survive and proliferate independent of glucose due to enhanced gluconeogenesis and oxidations of glutamine and branched chain amino acids, which together sustain the nonoxidative pentose pathway for purine synthesis. Silencing expression of fructose-1,6-bisphosphatases (FBP) in brain metastatic cells reduced their viability and improved the survival of metastasis-bearing immunocompetent hosts. Clinically, we showed that brain metastases from human breast cancer patients expressed higher levels of FBP and glycogen than the corresponding primary tumors. Together, our findings identify a critical metabolic condition required to sustain brain metastasis and suggest that targeting gluconeogenesis may help eradicate this deadly feature in advanced breast cancer patients.

Involvement of de novo synthesized palmitate and mitochondrial EGFR in EGF induced mitochondrial fusion of cancer cells.

Increased expressions of fatty acid synthase (FASN) and epidermal growth factor receptor (EGFR) are common in cancer cells. De novo synthesis of palmitate by FASN is critical for the survival of cancer cells via mechanisms independent of its role as an energy substrate. Besides the plasma membrane and the nucleus, EGFR can also localize at the mitochondria; however, signals that can activate mitochondrial EGFR (mtEGFR) and the functions of mtEGFR of cancer cells remain unknown. The present study characterizes mtEGFR in the mitochondria of cancer cells (prostate and breast) and reveals that mtEGFR can promote mitochondrial fusion through increasing the protein levels of fusion proteins PHB2 and OPA1. Activation of plasma membranous EGFR (pmEGFR) stimulates the de novo synthesis of palmitate through activation of FASN and ATP-citrate lyase (ACLy). In vitro kinase assay with isolated mitochondria shows that palmitate can activate mtEGFR. Inhibition of FASN blocks the mtEGFR phosphorylation and palmitoylation induced by EGF. Mutational studies show that the cysteine 797 is important for mtEGFR activation and palmitoylation. Inhibition of FASN can block EGF induced mitochondrial fusion and increased the sensitivity of prostate cancer cells to EGFR tyrosine kinase inhibitor. In conclusion, these results suggest that mtEGFR can be activated by pmEGFR through de novo synthesized palmitate to promote mitochondrial fusion and survival of cancer cells. This mechanism may serve as a novel target to improve EGFR-based cancer therapy.

ATP citrate lyase mediates resistance of colorectal cancer cells to SN38.

Combination chemotherapy is standard for metastatic colorectal cancer; however, nearly all patients develop drug resistance. Understanding the mechanisms that lead to resistance to individual chemotherapeutic agents may enable identification of novel targets and more effective therapy. Irinotecan is commonly used in first- and second-line therapy for patients with metastatic colorectal cancer, with the active metabolite being SN38. Emerging evidence suggests that altered metabolism in cancer cells is fundamentally involved in the development of drug resistance. Using Oncomine and unbiased proteomic profiling, we found that ATP citrate lyase (ACLy), the first-step rate-limiting enzyme for de novo lipogenesis, was upregulated in colorectal cancer compared with its levels in normal mucosa and in chemoresistant colorectal cancer cells compared with isogenic chemo-naïve colorectal cancer cells. Overexpression of exogenous ACLy by lentivirus transduction in chemo-naïve colorectal cancer cells led to significant chemoresistance to SN38 but not to 5-fluorouracil or oxaliplatin. Knockdown of ACLy by siRNA or inhibition of its activity by a small-molecule inhibitor sensitized chemo-naïve colorectal cancer cells to SN38. Furthermore, ACLy was significantly increased in cancer cells that had acquired resistance to SN38. In contrast to chemo-naïve cells, targeting ACLy alone was not effective in resensitizing resistant cells to SN38, due to a compensatory activation of the AKT pathway triggered by ACLy suppression. Combined inhibition of AKT signaling and ACLy successfully resensitized SN38-resistant cells to SN38. We conclude that targeting ACLy may improve the therapeutic effects of irinotecan and that simultaneous targeting of ACLy and AKT may be warranted to overcome SN38 resistance.

EGFR-SGLT1 interaction does not respond to EGFR modulators, but inhibition of SGLT1 sensitizes prostate cancer cells to EGFR tyrosine kinase inhibitors.

BACKGROUND: Overexpression of epidermal growth factor receptor (EGFR) is associated with poor prognosis in malignant tumors. Sodium/glucose co-transporter 1 (SGLT1) is an active glucose transporter that is overexpressed in many cancers including prostate cancer. Previously, we found that EGFR interacts with and stabilizes SGLT1 in cancer cells. METHODS: In this study, we determined the micro-domain of EGFR that is required for its interaction with SGLT1 and the effects of activation/inactivation of EGFR on EGFR-SGLT1 interaction, measured the expression of EGFR and SGLT1 in prostate cancer tissues, and tested the effect of inhibition of SGLT1 on the sensitivity of prostate cancer cells to EGFR tyrosine inhibitors. RESULTS: We found that the autophosphorylation region (978-1210 amino acids) of EGFR was required for its sufficient interaction with SGLT1 and that this interaction was independent of EGFR's tyrosine kinase activity. Most importantly, the EGFR-SGLT1 interaction does not respond to EGFR tyrosine kinase modulators (EGF and tyrosine kinase inhibitors). EGFR and SGLT1 co-localized in prostate cancer tissues, and inhibition of SGLT1 by a SGLT1 inhibitor (Phlorizin) sensitized prostate cancer cells to EGFR inhibitors (Gefitinib and Erlotinib). CONCLUSION: These data suggest that EGFR in cancer cells can exist as either a tyrosine kinase modulator responsive status or an irresponsive status. SGLT1 is a protein involved in EGFR's functions that are irresponsive to EGFR tyrosine kinase inhibitors and, therefore, the EGFR-SGLT1 interaction might be a novel target for prostate cancer therapy.

Intracellular ATP levels are a pivotal determinant of chemoresistance in colon cancer cells.

Altered metabolism in cancer cells is suspected to contribute to chemoresistance, but the precise mechanisms are unclear. Here, we show that intracellular ATP levels are a core determinant in the development of acquired cross-drug resistance of human colon cancer cells that harbor different genetic backgrounds. Drug-resistant cells were characterized by defective mitochondrial ATP production, elevated aerobic glycolysis, higher absolute levels of intracellular ATP, and enhanced HIF-1α-mediated signaling. Interestingly, direct delivery of ATP into cross-chemoresistant cells destabilized HIF-1α and inhibited glycolysis. Thus, drug-resistant cells exhibit a greater "ATP debt" defined as the extra amount of ATP needed to maintain homeostasis of survival pathways under genotoxic stress. Direct delivery of ATP was sufficient to render drug-sensitive cells drug resistant. Conversely, depleting ATP by cell treatment with an inhibitor of glycolysis, 3-bromopyruvate, was sufficient to sensitize cells cross-resistant to multiple chemotherapeutic drugs. In revealing that intracellular ATP levels are a core determinant of chemoresistance in colon cancer cells, our findings may offer a foundation for new improvements to colon cancer treatment.

Loss of EGFR induced autophagy sensitizes hormone refractory prostate cancer cells to adriamycin.

BACKGROUND: The epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, is over-expressed in advanced prostate cancer but tyrosine kinase inhibitors are not clinically effective in the treatment of prostate cancer. Recently it was found that EGFR in cancer cells has a kinase-independent pro-survival function, preventing cells from undergoing autophagy. In the present study we investigated whether the anti-autophagic function of EGFR may contribute to resistance of hormone-refractory prostate cancer cells to chemotherapeutic-induced apoptosis. METHODS: We first characterized the autophagic phenotype induced by knocking down EGFR in hormone refractory prostate cancer cells (PC-3MM2 and DU-145), then we tested whether loss of EGFR-induced autophagy could sensitize cancer cells to adriamycin. RESULTS: Using continuous live cell imaging techniques, we observed that knocking down EGFR lead to typical autophagic morphological/molecular changes, cell shrinkage without detachment, aggregation of microtubule-associated protein 1 light chain 3 (LC3) protein and absence of activation of apoptotic caspases 3/7. Loss of EGFR also increased the activity of calpain, which is pro-apoptotic. Knocking down EGFR, but not inhibiting its tyrosine kinase activity, significantly sensitized cells to adriamycin-induced apoptosis. Adriamycin-induced apoptosis could be inhibited by increased extracellular glucose level, suggesting intracellular glucose deficiency is a key mediator of the sensitization. The loss of EGFR induced autophagy and sensitization to adriamycin were also reproduced by using another hormone refractory prostate cancer cell line, Du145. CONCLUSION: Taken together, these data suggest that decreasing the expression level of EGFR protein, rather than inhibiting its tyrosine kinase activity, may enhance the efficiency of EGFR targeted therapy for prostate cancer.

Formation of solid tumors by a single multinucleated cancer cell.

BACKGROUND: Large multinucleated cells (MNCs) commonly exist in tumorigenic cancer cell lines that are used widely in research. However, the contributions of MNCs to tumorigenesis are unknown. METHODS: In this study, MNCs were characterized in the murine fibrosarcoma cell line UV-2237 in vitro and in vivo at the single-cell level. RESULTS: The authors observed that MNCs originated from a rare subpopulation of mononuclear cells and were positive for a senescent marker, ß-galactosidase. In addition, MNCs were responsible for the majority of clonogenic activity when cultured in hard agar; they were more resistant to chemotherapeutic agents than mononuclear cells; they could undergo asymmetric division (producing mononuclear cells) and self-renewal in vitro and in vivo; and, most important; a single MNC produced orthotopic, subcutaneous tumors (composed mainly of mononuclear cells) that gave rise to spontaneous lung metastases in nude mice. CONCLUSIONS: The current results indicated that the growth of MNCs may be arrested under stress and that MNCs are highly resistant to chemotherapy and can generate clonal, orthotopic, metastatic tumors.

Astrocytes upregulate survival genes in tumor cells and induce protection from chemotherapy.

In the United States, more than 40% of cancer patients develop brain metastasis. The median survival for untreated patients is 1 to 2 months, which may be extended to 6 months with conventional radiotherapy and chemotherapy. The growth and survival of metastasis depend on the interaction of tumor cells with host factors in the organ microenvironment. Brain metastases are surrounded and infiltrated by activated astrocytes and are highly resistant to chemotherapy. We report here that coculture of human breast cancer cells or lung cancer cells with murine astrocytes (but not murine fibroblasts) led to the up-regulation of survival genes, including GSTA5, BCL2L1, and TWIST1, in the tumor cells. The degree of up-regulation directly correlated with increased resistance to all tested chemotherapeutic agents. We further show that the up-regulation of the survival genes and consequent resistance are dependent on the direct contact between the astrocytes and tumor cells through gap junctions and are therefore transient. Knocking down these genes with specific small interfering RNA rendered the tumor cells sensitive to chemotherapeutic agents. These data clearly demonstrate that host cells in the microenvironment influence the biologic behavior of tumor cells and reinforce the contention that the organ microenvironment must be taken into consideration during the design of therapy.

The Chinese version of the Personal and Social Performance Scale (PSP): validity and reliability.

The Personal and Social Performance Scale (PSP) is a 100-point single-item rating scale that assesses four important domains of patients with mental disorders. This study was designed to examine the validity and reliability of a Chinese version of the PSP. The study was conducted in a sample of 157 patients with schizophrenia (confirmed by DSM-IV-TR criteria, SCID-P interview). The internal consistency (Cronbach's alpha=0.84) and the inter-rater reliability (kappa value=0.82, ICC=0.94 for PSP total score) was good. The test-retest reliability was high (intraclass correlation coefficient (ICC) of 0.95). The scale showed good construct validity with statistically significant correlations with the Global Assessment of Functioning Scale (GAF) (ICC of 0.95). The PSP score had a good negative correlation with the Positive and Negative Syndrome Scale (PANSS) total score. The improvement in PSP after 8 weeks of treatment was significantly correlated with the reduction in PANSS: after 8 weeks of treatment, the responders (defined as those with a reduction in PANSS total score ≥50%) experienced a greater improvement in PSP than the non-responders. The Chinese version of the PSP is a convenient and valid instrument to assess the personal and social functions of stabilized and acute patients with schizophrenia.

ARD1 stabilization of TSC2 suppresses tumorigenesis through the mTOR signaling pathway.

Mammalian target of rapamycin (mTOR) regulates various cellular functions, including tumorigenesis, and is inhibited by the tuberous sclerosis 1 (TSC1)-TSC2 complex. Here, we demonstrate that arrest-defective protein 1 (ARD1) physically interacts with, acetylates, and stabilizes TSC2, thereby repressing mTOR activity. The inhibition of mTOR by ARD1 inhibits cell proliferation and increases autophagy, thereby inhibiting tumorigenicity. Correlation between ARD1 and TSC2 abundance was apparent in multiple tumor types. Moreover, evaluation of loss of heterozygosity at Xq28 revealed allelic loss in 31% of tested breast cancer cell lines and tumor samples. Together, our findings suggest that ARD1 functions as an inhibitor of the mTOR pathway and that dysregulation of the ARD1-TSC2-mTOR axis may contribute to cancer development.