Blocking reverse electron transfer-mediated mitochondrial DNA oxidation rescues cells from PANoptosis.

PANoptosis is a new type of cell death featured with pyroptosis, apoptosis and necroptosis, and is implicated in organ injury and mortality in various inflammatory diseases, such as sepsis and hemophagocytic lymphohistiocytosis (HLH). Reverse electron transport (RET)-mediated mitochondrial reactive oxygen species (mtROS) has been shown to contribute to pyroptosis and necroptosis. In this study we investigated the roles of mtROS and RET in PANoptosis induced by TGF-ß-activated kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (Oxo) plus lipopolysaccharide (LPS) as well as the effects of anti-RET reagents on PANoptosis. We showed that pretreatment with anti-RET reagents 1-methoxy PMS (MPMS) or dimethyl fumarate (DMF) dose-dependently inhibited PANoptosis in macrophages BMDMs and J774A.1 cells induced by Oxo/LPS treatment assayed by propidium iodide (PI) staining. The three arms of the PANoptosis signaling pathway, namely pyroptosis, apoptosis and necroptosis signaling, as well as the formation of PANoptosomes were all inhibited by MPMS or DMF. We demonstrated that Oxo/LPS treatment induced RET and mtROS in BMDMs, which were reversed by MPMS or DMF pretreatment. Interestingly, the PANoptosome was co-located with mitochondria, in which the mitochondrial DNA was oxidized. MPMS and DMF fully blocked the mtROS production and the formation of PANoptosome induced by Oxo plus LPS treatment. An HLH mouse model was established by poly(I:C)/LPS challenge. Pretreatment with DMF (50 mg·kg-1·d-1, i.g. for 3 days) or MPMS (10 mg·kg-1·d-1, i.p. for 2 days) (DMF i.g. MPMS i.p.) effectively alleviated HLH lesions accompanied by decreased hallmarks of PANoptosis in the liver and kidney. Collectively, RET and mtDNA play crucial roles in PANoptosis induction and anti-RET reagents represent a novel class of PANoptosis inhibitors by blocking oxidation of mtDNA, highlighting their potential application in treating PANoptosis-related inflammatory diseases. PANoptotic stimulation induces reverse electron transport (RET) and reactive oxygen species (ROS) in mitochondia, while 1-methoxy PMS and dimethyl fumarate can inhibit PANoptosis by suppressing RETmediated oxidation of mitochondrial DNA.

Baicalin inhibits PANoptosis by blocking mitochondrial Z-DNA formation and ZBP1-PANoptosome assembly in macrophages.

PANoptosis is an emerging form of regulated cell death (RCD) characterized by simultaneous activation of pyroptotic, apoptotic, and necroptotic signaling that not only participates in pathologies of inflammatory diseases but also has a critical role against pathogenic infections. Targeting PANoptosis represents a promising therapeutic strategy for related inflammatory diseases, but identification of inhibitors for PANoptosis remains an unmet demand. Baicalin () is an active flavonoid isolated from Scutellaria baicalensis Georgi (Huangqin), a traditional Chinese medicinal herb used for heat-clearing and detoxifying. Numerous studies suggest that baicalin possesses inhibitory activities on various forms of RCD including apoptosis/secondary necrosis, pyroptosis, and necroptosis, thereby mitigating inflammatory responses. In this study we investigated the effects of baicalin on PANoptosis in macrophage cellular models. Primary macrophages (BMDMs) or J774A.1 macrophage cells were treated with 5Z-7-oxozeaenol (OXO, an inhibitor for TAK1) in combination with TNF-α or LPS. We showed that OXO plus TNF-α or LPS induced robust lytic cell death, which was dose-dependently inhibited by baicalin (50-200 µM). We demonstrated that PANoptosis induction was accompanied by overt mitochondrial injury, mitochondrial DNA (mtDNA) release and Z-DNA formation. Z-DNA was formed from cytosolic oxidized mtDNA. Both oxidized mtDNA and mitochondrial Z-DNA puncta were co-localized with the PANoptosome (including ZBP1, RIPK3, ASC, and caspase-8), a platform for mediating PANoptosis. Intriguingly, baicalin not only prevented mitochondrial injury but also blocked mtDNA release, Z-DNA formation and PANoptosome assembly. Knockdown of ZBP1 markedly decreased PANoptotic cell death. In a mouse model of hemophagocytic lymphohistiocytosis (HLH), administration of baicalin (200 mg/kg, i.g., for 4 times) significantly mitigated lung and liver injury and reduced levels of serum TNF-α and IFN-γ, concomitant with decreased levels of PANoptosis hallmarks in these organs. Baicalin also abrogated the hallmarks of PANoptosis in liver-resident macrophages (Kupffer cells) in HLH mice. Collectively, our results demonstrate that baicalin inhibits PANoptosis in macrophages by blocking mitochondrial Z-DNA formation and ZBP1-PANoptosome assembly, thus conferring protection against inflammatory diseases. PANoptosis is a form of regulated cell death displaying simultaneous activation of pyroptotic, apoptotic, and necroptotic signaling. This study shows that induction of PANoptosis is linked to mitochondrial dysfunction and mitochondrial Z-DNA formation. Baicalin inhibits PANoptosis in macrophages in vitro via blocking mitochondrial dysfunction and the mitochondrial Z-DNA formation and thereby impeding the assembly of ZBP1-associated PANoptosome. In a mouse model of hemophagocytic lymphohistiocytosis (HLH), baicalin inhibits the activation of PANoptotic signaling in liver-resident macrophages (Kupffer cells) in vivo, thus mitigating systemic inflammation and multiple organ injury in mice.

Theaflavin mitigates acute gouty peritonitis and septic organ injury in mice by suppressing NLRP3 inflammasome assembly.

Activation of NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays important role in defending against infections, but its aberrant activation is causally linked to many inflammatory diseases, thus being a therapeutic target for these diseases. Theaflavin, one major ingredient of black tea, exhibits potent anti-inflammatory and anti-oxidative activities. In this study, we investigated the therapeutic effects of theaflavin against NLRP3 inflammasome activation in macrophages in vitro and in animal models of related diseases. We showed that theaflavin (50, 100, 200 µM) dose-dependently inhibited NLRP3 inflammasome activation in LPS-primed macrophages stimulated with ATP, nigericin or monosodium urate crystals (MSU), evidenced by reduced release of caspase-1p10 and mature interleukin-1ß (IL-1ß). Theaflavin treatment also inhibited pyroptosis as shown by decreased generation of N-terminal fragment of gasdermin D (GSDMD-NT) and propidium iodide incorporation. Consistent with these, theaflavin treatment suppressed ASC speck formation and oligomerization in macrophages stimulated with ATP or nigericin, suggesting reduced inflammasome assembly. We revealed that theaflavin-induced inhibition on NLRP3 inflammasome assembly and pyroptosis resulted from ameliorated mitochondrial dysfunction and reduced mitochondrial ROS production, thereby suppressing interaction between NLRP3 and NEK7 downstream of ROS. Moreover, we showed that oral administration of theaflavin significantly attenuated MSU-induced mouse peritonitis and improved the survival of mice with bacterial sepsis. Consistently, theaflavin administration significantly reduced serum levels of inflammatory cytokines including IL-1ß and attenuated liver inflammation and renal injury of mice with sepsis, concomitant with reduced generation of caspase-1p10 and GSDMD-NT in the liver and kidney. Together, we demonstrate that theaflavin suppresses NLRP3 inflammasome activation and pyroptosis by protecting mitochondrial function, thus mitigating acute gouty peritonitis and bacterial sepsis in mice, highlighting a potential application in treating NLRP3 inflammasome-related diseases.

Gout-associated monosodium urate crystal-induced necrosis is independent of NLRP3 activity but can be suppressed by combined inhibitors for multiple signaling pathways.

Monosodium urate (MSU) crystals, the etiological agent of gout, are formed in joints and periarticular tissues due to long-lasting hyperuricemia. Although MSU crystal-triggered NLRP3 inflammasome activation and interleukin 1ß (IL-1ß) release are known to have key roles in gouty arthritis, recent studies revealed that MSU crystal-induced necrosis also plays a critical role in this process. However, it remains unknown what forms of necrosis have been induced and whether combined cell death inhibitors can block such necrosis. Here, we showed that MSU crystal-induced necrosis in murine macrophages was not dependent on NLRP3 inflammasome activation, as neither genetic deletion nor pharmacological blockade of the NLRP3 pathway inhibited the necrosis. Although many cell death pathways (such as ferroptosis and pyroptosis) inhibitors or reactive oxygen species inhibitors did not have any suppressive effects, necroptosis pathway inhibitors GSK'872 (RIPK3 inhibitor), and GW806742X (MLKL inhibitor) dose-dependently inhibited MSU crystal-induced necrosis. Moreover, a triple combination of GSK'872, GW806742X, and IDN-6556 (pan-caspase inhibitor) displayed enhanced inhibition of the necrosis, which was further fortified by the addition of MCC950 (NLRP3 inhibitor), suggesting that multiple cell death pathways might have been triggered by MSU crystals. Baicalin, a previously identified inhibitor of NLRP3, inhibited MSU crystal-induced inflammasome activation and suppressed the necrosis in macrophages. Besides, baicalin gavage significantly ameliorated MSU crystal-induced peritonitis in mice. Altogether, our data indicate that MSU crystals induce NLRP3-independent necrosis, which can be inhibited by combined inhibitors for multiple signaling pathways, highlighting a new avenue for the treatment of gouty arthritis.

miR-34a inhibits differentiation of human adipose tissue-derived stem cells by regulating cell cycle and senescence induction.

MicroRNAs (miRNAs) are critical in the maintenance, differentiation, and lineage commitment of stem cells. Stem cells have the unique property to differentiate into tissue-specific cell types (lineage commitment) during cell division (self-renewal). In this study, we investigated whether miR-34a, a cell cycle-regulating microRNA, could control the stem cell properties of adipose tissue-derived stem cells (ADSCs). First, we found that the expression level of miR-34a was increased as the cell passage number was increased. This finding, however, was inversely correlated with our finding that the overexpression of miR-34a induced the decrease of cell proliferation. In addition, miR-34a overexpression decreased the expression of various cell cycle regulators such as CDKs (-2, -4, -6) and cyclins (-E, -D), but not p21 and p53. The cell cycle analysis showed accumulation of dividing cells at S phase by miR-34a, which was reversible by co-treatment with anti-miR-34a. The potential of adipogenesis and osteogenesis of ADSCs was also decreased by miR-34a overexpression, which was recovered by co-treatment with anti-miR-34a. The surface expression of stem cell markers including CD44 was also down-regulated by miR-34a overexpression as similar to that elicited by cell cycle inhibitors. miR-34a also caused a significant decrease in mRNA expression of stem cell transcription factors as well as STAT-3 expression and phosphorylation. Cytokine profiling revealed that miR-34a significantly modulated IL-6 and -8 production, which was strongly related to cellular senescence. These data suggest the importance of miR-34a for the fate of ADSCs toward senescence rather than differentiation.

The endoplasmic reticulum stress marker, glucose-regulated protein-78 (GRP78) in visceral adipocytes predicts endometrial cancer progression and patient survival.

OBJECTIVE: Currently, accurately identifying endometrial cancer patients at high risk for recurrence remains poor. To ascertain if changes in the endoplasmic reticulum (ER) stress marker, glucose-regulated-protein-78 (GRP78) can serve as a prognosticator in endometrial cancer, we examined GRP78 expression in patient samples to determine its association with clinical outcome. METHODS: A retrospective cohort study was conducted in endometrial cancer patients. Archived specimens of visceral adipocytes and paired endometrial tumors were analyzed by immunohistochemistry for GRP78 and another ER stress marker, C/EBP homologous protein (CHOP). Expression of these markers was correlated with clinico-pathological information and outcomes. RESULTS: GRP78 expression in visceral adipocytes was detected in 95% of the 179 endometrial cancer patients with analyzable visceral adipocytes. Within individual samples, 24% of adipocytes (range, 0-90%, interquartile range 18%-38%) exhibited GRP78 expression. High visceral adipocyte GRP78 expression positively correlated with advanced-stage disease (p=0.007) and deep myometrial invasion (p=0.004). High visceral adipocyte GRP78 expression was significantly associated with decreased disease-free survival (DFS) in multivariate analyses (hazard ratio 2.88, 95% CI 1.37-6.04, p=0.005). CHOP expression paralleled the GRP78 expression in adipocytes (r=0.55, p<0.001) and in the tumor (p=0.018). CONCLUSIONS: Our study demonstrates that the ER stress markers, GRP78 and CHOP, are elevated in endometrial cancer patients. Furthermore, GRP78 expression levels in visceral adipocytes from these patients were significantly correlated to disease stage and patient survival. Our results demonstrate, for the first time, that the GRP78 levels in endometrial cancer patients may be a prognosticator and aid with clinical risk stratification and focused surveillance.

Cell cycle regulators are critical for maintaining the differentiation potential and immaturity in adipogenesis of adipose-derived stem cells.

A single cell division is governed by the catalytic reactions of cyclins and cyclin-dependent kinases (CDKs). Stem cells are unique in that they can differentiate into tissue-specific cell types (lineage commitment) during cell division (self-renewal). In this study, we analyzed changes in the differentiation potency of adipose tissue-derived stem cells (ADSCs) according to the number of spontaneous cell divisions. We used low passage number (p3) to late passage number (p60) adipose-derived stem cells (ADSCs) as our model system. A preliminary investigation of the typical stem cell phenotypes revealed that CD44 expression decreased remarkably as the passage number of the ADSCs increased. Further examinations revealed that the higher the cell passage number, the lower the cell proliferation capability, differentiation potency, and expression of stem cell transcriptional factors and cell cycle regulators such as cyclins E, A, B, CDK2, and CDK1/CDC2. To verify if the observed changes in differentiation potency according to the number of cell divisions were related to cell cycle regulators, p3 ADSCs were treated with the selective CDK2 and CDK1/CDC2 inhibitor Purvalanol A. Inhibitor treatment of p3 ADSCs induced changes in the morphology, differentiation potency, and pattern of stem cell transcriptional factor expression so that these low passage ADSCs more closely resembled high-passage ADSCs. Collectively, our results indicate that cell cycle regulators control the differentiation potency of ADSCs, and provide insights into the cell biology and differentiation potency of ADSCs according to the number of cell divisions.

The immunosuppressive effect of gossypol in mice is mediated by inhibition of lymphocyte proliferation and by induction of cell apoptosis.

AIM: To investigate the immunosuppressive effect of gossypol in mice both in vitro and in vivo. METHODS: The in vitro effect of gossypol on the proliferation of lymphocytes isolated from lymph nodes of BALB/c mice was determined by CFSE staining and by an MTS assay. Lymphocyte activation and lymphoblastic transformation were evaluated with immunostaining. Cell apoptosis was detected by Annexin-V and Hoechst 33342 staining. The in vivo immunosuppressive effect of gossypol on the DTH reaction was evaluated using a mouse DTH model induced by 2,4-dinitro-1-fluorobenzene (DNFB). The thickness of the ears was measured, and the histological changes of the mouse auricles were observed after hematoxylin-eosin staining. The proliferation capacity of lymphocytes from DTH mice was also assayed. RESULTS: In vitro, gossypol could significantly inhibit the proliferation of mouse lymphocytes stimulated with phorbol ester plus ionomycin in a dose-dependent manner. Although the expression of the early activation antigen CD69 was not affected, the lymphoblastic transformation of both T and B lymphocyte subsets was significantly suppressed by gossypol. Moreover, gossypol could induce apoptosis of lymphocytes, and the effect was time- and dose-dependent. In vivo, the DTH reaction in mice was markedly alleviated by gossypol injected intraperitoneally. Lymphocytes from drug-treated DTH mice had a reduced proliferation capacity as compared with lymphocytes from untreated DTH mice. Gossypol treatment also markedly reduced the number of infiltrated lymphocytes in the auricles of DTH mice. CONCLUSION: Gossypol exhibited immunosuppressive effects in mice, probably by inhibition of lymphocyte proliferation and by induction of cell apoptosis.

Thymidylate synthase polymorphisms and mRNA expression are independent chemotherapy predictive markers in esophageal adenocarcinoma patients.

Thymidylate synthase (TS) is known to have polymorphisms in the 5' and 3' untranslated region (UTR). These polymorphisms have been reported to be associated with high TS expression and chemoresistance to 5-FU. The aim of this study was to examine the prognostic roles of the 5'-UTR and 3'-UTR TS polymorphisms in esophageal adenocarcinoma patients, as well as their relation with TS mRNA expression. Eighty-three patients with esophageal adenocarcinoma were assessed. Thirty-four had received 5-FU containing chemotherapy and 49 were treated with surgery alone. Surgically resected tumor tissues were analyzed for TS genotype and TS mRNA expression using a quantitative real-time RT-PCR method. No survival difference was seen between the patients with 3RG allele (3RG group) and non-3RG group among surgery-alone patients. However, among patients with a history of 5-FU-based chemotherapy, the non-3RG group showed significantly better overall survival compared to the 3RG group (p=0.02). Moreover, whereas chemotherapy produced a significant increase in survival for the non-3RG group patients, those in the 3RG group obtained no survival benefit from chemotherapy. When patients were classified by low or high TS mRNA expression levels, low TS expressers obtained survival benefit from chemotherapy while high TS expressers did not, although there was no difference of median TS mRNA levels between 3RG and non-3RG group. The 3'-UTR polymorphism was not associated with overall survival. These results suggest that the status of the TS 5'-UTR polymorphism and TS mRNA expression are independent predictive markers for survival benefit from 5-FU-based therapy.

DPD is a molecular determinant of capecitabine efficacy in colorectal cancer.

Capecitabine is a fluoropyrimidine-based drug that offers physicians a more convenient treatment for advanced colorectal cancer (CRC), with manageable toxicity and antitumor activity comparable to that of continuous-infusion therapies with 5-fluorouracil (5-FU). However, there are no validated and established predictive factors for clinical outcome of capecitabine efficacy in CRC. The gene expressions of the pyrimidine metabolism enzymes dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and thymidylate synthase (TS) have previously been shown to be response determinants of fluoropyrimidine-based drugs in various tumors. Therefore, we investigated whether intratumoral mRNA expression levels of these genes are also associated with the clinical outcome of patients with metastatic CRC treated with first-line capecitabine. Thirty-seven patients with metastatic CRC were enrolled in this study and treated with single agent capecitabine. The intratumoral mRNA levels of DPD, TP and TS were assessed from paraffin-embedded tissue samples using laser-capture-microdissection methods and quantitative real-time PCR. There were 20 women and 17 men with a median age of 61 years (range 49-74). The median progression-free survival was 6.7 months (95% CI, 4.8-11.6 months), with a median follow-up of 14.4 months (range 1.3-18.7 months). Complete response was observed in 1 (3%), partial response in 6 (20%), stable disease in 14 (47%) and progressive disease in 9 (30%) patients (response was inevaluable in 7 patients). Higher gene expression levels of DPD were associated with resistance to capecitabine (P=0.032; Kruskal-Wallis test). Patients with a lower mRNA amount of DPD (

Molecular determinants of cetuximab efficacy.

PURPOSE: To investigate whether mRNA expression levels of cyclin D1 (CCND1), cyclooxygenase 2 (Cox-2), epidermal growth factor receptor (EGFR), interleukin 8 (IL-8), and vascular endothelial growth factor (VEGF), all members of the EGFR signaling pathway, are associated with clinical outcome in patients with EGFR-expressing metastatic colorectal cancer (CRC) treated with cetuximab. PATIENTS AND METHODS: Thirty-nine patients with metastatic CRC, refractory to both irinotecan and oxaliplatin, were enrolled on IMCL-0144 and treated with single-agent cetuximab. The intratumoral mRNA levels of CCND1, Cox-2, EGFR, IL-8, and VEGF were assessed from paraffin-embedded tissue samples using laser-capture microdissection and quantitative real-time polymerase chain reaction. RESULTS: There were 21 women and 18 men with a median age of 64 years (range, 35 to 83 years). Higher gene expression levels of VEGF were associated with resistance to cetuximab (P = .038; Kruskal-Wallis test). The combination of low gene expression levels of Cox-2, EGFR, and IL-8 was significantly associated with overall survival (13.5 v 2.3 months; P = .028; log-rank test). Both findings were independent of skin toxicity that was itself significantly correlated to survival. Patients with a lower mRNA amount of EGFR had a longer overall survival compared with patients that had a higher mRNA amount (7.3 v 2.2 months; P = .09; log-rank test). Patients with lower expression of Cox-2 had a significantly higher rate of grade 2 to 3 skin reactions under cetuximab treatment. CONCLUSION: This pilot study suggests that gene expression levels of Cox-2, EGFR, IL-8, and VEGF in patients with metastatic CRC may be useful markers of clinical outcome in single-agent cetuximab treatment.

Sex differences in the predictive power of the molecular prognostic factor HER2/neu in patients with non-small-cell lung cancer.

BACKGROUND: Recent studies imply that HER2/neu is a potential prognostic factor in patients with non-small-cell lung cancer (NSCLC). Whereas considerable evidence indicates sex differences in epidemiologic, hormonal, biologic, and genetic factors in this disease, it has remained unknown whether HER2/neu has a diverse function as a prognostic factor in men and women. PATIENTS AND METHODS: We investigated the association between gene expression levels of HER2/neu in the primary tumors of 90 patients with curable resected NSCLC and survival, especially analyzing whether there is a different potential of this molecular factor in its prognostic impact between men and women. RESULTS: High HER2/neu gene expression levels were found in 62 patients (68.9%), and low HER2/neu gene expression levels were found in 28 patients (31.1%). High HER2/neu messenger RNA expression levels were associated with inferior survival (P = 0.09) compared with lower HER2/neu expression. Survival analysis was then carried out separately for men and women in this group of patients. An HER2/neu gene expression cutoff point was identified that separated women, but not men, into good and poor prognostic groups. CONCLUSION: These findings suggest that HER2/neu as a prognostic factor is strongly sex specific, indicating that it is not useful for men but highly predictive for women.

Epidermal growth factor receptor gene polymorphisms predict pelvic recurrence in patients with rectal cancer treated with chemoradiation.

An association between epidermal growth factor receptor (EGFR) signaling pathway and response of cancer cells to ionizing radiation has been reported. Recently, a polymorphic variant in the EGFR gene that leads to an arginine-to-lysine substitution in the extracellular domain at codon 497 within subdomain IV of EGFR has been identified. The variant EGFR (HER-1 497K) may lead to attenuation in ligand binding, growth stimulation, tyrosine kinase activation, and induction of proto-oncogenes myc, fos, and jun. A (CA)(n) repeat polymorphism in intron 1 of the EGFR gene that alters EGFR expression in vitro and in vivo has also been described. In the current pilot study, we assessed both polymorphisms in 59 patients with locally advanced rectal cancer treated with adjuvant or neoadjuvant chemoradiation therapy using PCR-RFLP and a 5'-end [gamma-(33)P]ATP-labeled PCR protocol. We tested whether either polymorphism alone or in combination can be associated with local recurrence in the setting of chemoradiation treatment. We found that patients with HER-1 497 Arg/Arg genotype or lower number of CA repeats (both alleles <20) tended to have a higher risk of local recurrence (P = 0.24 and 0.31, respectively). Combined analysis showed the highest risk for local recurrence was seen in patients who possessed both a HER-1 497 Arg allele and <20 CA repeats (P = 0.05, log-rank test). Our data suggest that the HER-1 R497K and EGFR intron 1 (CA)(n) repeat polymorphisms may be potential indicators of radiosensitivity in patients with rectal cancer treated with chemoradiation.

Absence of nasal bone and brachydactyly: a probable new familial syndrome.

Brachydactyly is a relatively common congenital abnormality and can be associated with many other malformations. However, brachydactyly in association with absence of nasal bone is rare. Two Chinese siblings with a combination of nasal bone absence and brachydactyly are presented, apparently without other abnormalities. This combination of features do not fit into any previously described syndrome and we suggest that this case represents a new familial syndrome. Molecular genetics screening didn't revealed any specific pathogenic variants in the two siblings.

Cyclin-dependent kinase 4 signaling acts as a molecular switch between syngenic differentiation and neural transdifferentiation in human mesenchymal stem cells.

Multipotent mesenchymal stem/stromal cells (MSCs) are capable of differentiating into a variety of cell types from different germ layers. However, the molecular and biochemical mechanisms underlying the transdifferentiation of MSCs into specific cell types still need to be elucidated. In this study, we unexpectedly found that treatment of human adipose- and bone marrow-derived MSCs with cyclin-dependent kinase (CDK) inhibitor, in particular CDK4 inhibitor, selectively led to transdifferentiation into neural cells with a high frequency. Specifically, targeted inhibition of CDK4 expression using recombinant adenovial shRNA induced the neural transdifferentiation of human MSCs. However, the inhibition of CDK4 activity attenuated the syngenic differentiation of human adipose-derived MSCs. Importantly, the forced regulation of CDK4 activity showed reciprocal reversibility between neural differentiation and dedifferentiation of human MSCs. Together, these results provide novel molecular evidence underlying the neural transdifferentiation of human MSCs; in addition, CDK4 signaling appears to act as a molecular switch from syngenic differentiation to neural transdifferentiation of human MSCs.

A new lectin from the sea worm Serpula vermicularis: isolation, characterization and anti-HIV activity.

A GlcNAc-specific lectin was isolated from the sea worm Serpula vermicularis (SVL) (Annelida) and purified by ion-exchange, affinity and gel permeation chromatography. SVL was a homotetrameric protein with native molecular mass of about 50 kDa, and consisted of identical subunits of 12.7 kDa. The carbohydrate content of 1.9% suggested that the lectin was a glycoprotein, and mainly composed by aspartic and glutamic acids, glycine, valine and serine; with relatively lower content of basic amino acids and cysteine. The first 15 residues of the N-terminal region were determined as ADTPCQMLGSRYGWR. It was stable at pH 6-9 and at temperatures up to 40 degrees C. SVL was Ca(2+)-independent lectin that agglutinated native and trypsinized human erythrocytes. Hapten inhibition studies indicated that SVL showed binding specificity only for N-acetyl-d-glucosamine and its derivatives among the monosaccharides tested and required the presence of hydroxyl group at the C-3 of GlcNAc. The presence of hydrophobic p-nitrophenyl aglycone improved inhibitory potency of N-acetyl-d-glucosamine. Ovomucoid and ovalbumin were found to be inhibitors among the glycoproteins used for inhibition assay. The anti-HIV-1 (human immunodeficiency virus) activity of SVL in vitro was determined: SVL inhibited the production of viral p24 antigen and cytopathic effect induced by HIV-1. The EC(50) values were 0.23 and 0.15 microg x mL(-1) respectively.

Association of methylenetetrahydrofolate reductase gene polymorphisms and sex-specific survival in patients with metastatic colon cancer.

PURPOSE: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating intracellular folate levels, which affects DNA synthesis and methylation. Two MTHFR gene polymorphisms, C677T and A1298C, are linked to altered enzyme activity. Several studies have shown these two polymorphisms to be associated with response to fluorouracil (FU) -based treatment in advanced colon cancer patients, but data are inconsistent and contradictory. Meanwhile, epidemiologic studies demonstrated that these MTHFR polymorphisms were associated with cancer risk in a sex-specific manner. We tested the hypothesis of whether these two polymorphisms are associated with sex-specific clinical outcome in metastatic colon cancer patients treated with FU-based chemotherapy. PATIENTS AND METHODS: This study included 318 patients (177 men and 141 women) with metastatic colon cancer treated between 1992 and 2003 at the University of Southern California/Norris Comprehensive Cancer Center or Los Angeles County/University of Southern California Medical Center. Peripheral blood samples were collected from each patient, and genomic DNA was extracted from WBCs. Two MTHFR gene polymorphisms (C677T and A1298C) were tested by fluorogenic 5'-nuclease assay. RESULTS: The A1298C polymorphism showed statistically significant differences in overall survival (OS) in female, but not male, patients with metastatic colon cancer (log-rank test, P = .038). Among females, OS was greater for patients with the A/A genotype (n = 67; median OS, 18.4 months) compared with patients with the A/C genotype (n = 50; median OS, 13.9 months) or C/C genotype (n = 10; median OS, 15.6 months). CONCLUSION: Although preliminary, these data support the role of the A1298C polymorphism in MTHFR as prognostic marker in female patients with metastatic colon cancer. Further studies are needed to confirm these findings.