Loss of SHROOM3 affects neuroepithelial cell shape through regulating cytoskeleton proteins in cynomolgus monkey organoids.

Neural tube defects (NTDs) are severe congenital neurodevelopmental disorders arising from incomplete neural tube closure. Although folate supplementation has been shown to mitigate the incidence of NTDs, some cases, often attributable to genetic factors, remain unpreventable. The SHROOM3 gene has been implicated in NTD cases that are unresponsive to folate supplementation; at present, however, the underlying mechanism remains unclear. Neural tube morphogenesis is a complex process involving the folding of the planar epithelium of the neural plate. To determine the role of SHROOM3 in early developmental morphogenesis, we established a neuroepithelial organoid culture system derived from cynomolgus monkeys to closely mimic the in vivo neural plate phase. Loss of SHROOM3 resulted in shorter neuroepithelial cells and smaller nuclei. These morphological changes were attributed to the insufficient recruitment of cytoskeletal proteins, namely fibrous actin (F-actin), myosin II, and phospho-myosin light chain (PMLC), to the apical side of the neuroepithelial cells. Notably, these defects were not rescued by folate supplementation. RNA sequencing revealed that differentially expressed genes were enriched in biological processes associated with cellular and organ morphogenesis. In summary, we established an authentic in vitro system to study NTDs and identified a novel mechanism for NTDs that are unresponsive to folate supplementation.

Identification and validation of an immune-related lncRNAs signature to predict the overall survival of ovarian cancer.

Ovarian cancer (OC) is the most lethal gynecological cancer in women. Studies had reported that immune-related lncRNAs signatures were valuable in predicting the survival and prognosis of patients with various cancers. In our study, the prognostic value of immune-related lncRNAs was investigated in OC patients from TCGA-RNA-seq cohort (n=378) and HG-U133_Plus_2 cohort (n=590), respectively. Pearson correlation analysis was implemented to screen the immune-related lncRNA and then univariate Cox regression analysis was performed to explore their prognostic value in OC patients. Five prognostic immune-related lncRNAs were identified as prognostic lncRNAs. Besides, they were inputted into a LASSO Cox regression to establish and validate an immune-related lncRNA prognostic signature in TCGA-RNA-Seq cohort and HG-U133_Plus_2 cohort, respectively. Based on the best cut-off value of risk score, patients were divided into high- and low-risk groups. Survival analysis suggested that patients in the high-risk group had a worse overall survival (OS) than those in the low-risk group in both cohorts. The association between clinicopathological feathers and risk score was then evaluated by using stratification analysis. Moreover, we constructed a nomogram based on risk score, age and stage, which had a strong ability to forecast the OS of the OC patients. The influence of risk score on immune infiltration and immunotherapy response were assessed and the results suggested that patients with high-risk score might recruit multiple immune cells and stromal cells, leading to facilitating immune surveillance evasive. Ultimately, we demonstrated that the risk model was associated with chemotherapy response of multiple antitumor drugs, especially for paclitaxel, metformin and veliparib, which are commonly used in treating OC patients. In conclusion, we constructed a novel immune-related lncRNA signature, which had a potential prognostic value for OC patients and might facilitate personalized counselling for immunotherapy and chemotherapy.

[MRI/TRUS cognitive fusion combined with 12-core systematic transperineal prostate biopsy for the diagnosis of clinically significant prostate cancer: A report of 208 cases].

OBJECTIVE: To investigate the detection rate and complications of magnetic resonance imaging / transrectal ultrasonography (MRI/TRUS) cognitive fusion combined with 12-core systematic transperineal prostate biopsy (TPPB) in the diagnosis of clinically significant PCa (CS-PCa). METHODS: This retrospective study included 208 patients undergoing first-time MRI/TRUS cognitive fusion combined with 12-core systematic TPPB from June 2015 to May 2019. The patients, aged 54－85 (67.6 ± 7.8) years, all received digital rectal examination, PSA detection, TRUS and prostate multiparametric MRI (mpMRI) before biopsy. We analyzed the mpMRI images, identified and marked the suspected signal areas, repeated TRUS for further observation of the prostate, conducted cognitive fusion based on the mpMRI images and determined the target before 12-core systematic TPPB and subjecting the samples obtained to pathological examination. RESULTS: Of the 208 patients, 112 were diagnosed with CS-PCa (no case with tPSA < 4 µg/L, 21 cases with 4 µg/L ≤ tPSA < 10 µg/L, 47 cases with 10 µg/L ≤ tPSA < 20 µg/L, 40 cases with 20 µg/L ≤ tPSA < 100 µg/L, and 4 cases with tPSA ≥ 100 µg/L), 85 with BPH, 8 with chronic prostatitis, 2 with atypical prostatic hyperplasia, and 1 with prostatic intraepithelial neoplasia. Systemic inflammatory response syndrome occurred in 3 and gross hematuria and/or bloody stool in 12 cases after biopsy, which were all cured by anti-infection and hemostasis treatment. CONCLUSIONS: MRI/TRUS cognitive fusion combined with 12-core systematic transperineal prostate biopsy can improve the detection rate of the initial diagnosis of clinically significant PCa with a low incidence of controllable complications.

Development of a novel transcription factors-related prognostic signature for serous ovarian cancer.

Growing evidence suggest that transcription factors (TFs) play vital roles in serous ovarian cancer (SOC). In the present study, TFs mRNA expression profiles of 564 SOC subjects in the TCGA database, and 70 SOC subjects in the GEO database were screened. A 17-TFs related prognostic signature was constructed using lasso cox regression and validated in the TCGA and GEO cohorts. Consensus clustering analysis was applied to establish a cluster model. The 17-TFs related prognostic signature, risk score and cluster models were effective at accurately distinguishing the overall survival of SOC. Analysis of genomic alterations were used to elaborate on the association between the 17-TFs related prognostic signature and genomic aberrations. The GSEA assay results suggested that there was a significant difference in the inflammatory and immune response pathways between the high-risk and low-risk score groups. The potential immune infiltration, immunotherapy, and chemotherapy responses were analyzed due to the significant difference in the regulation of lymphocyte migration and T cell-mediated cytotoxicity between the two groups. The results indicated that patients with low-risk score were more likely to respond anti-PD-1, etoposide, paclitaxel, and veliparib but not to gemcitabine, doxorubicin, docetaxel, and cisplatin. Also, the prognostic nomogram model revealed that the risk score was a good prognostic indicator for SOC patients. In conclusion, we explored the prognostic values of TFs in SOC and developed a 17-TFs related prognostic signature to predict the survival of SOC patients.

Celastrol acts synergistically with afatinib to suppress non-small cell lung cancer cell proliferation by inducing paraptosis.

Non-small cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is intrinsic resistance to EGFR-tyrosine kinase inhibitors (TKIs), such as afatinib. Celastrol, a natural compound with antitumor activity, was reported to induce paraptosis in cancer cells. In this study, intrinsic EGFR-TKI-resistant NSCLC cell lines H23 (EGFR wild-type and KRAS mutation) and H292 (EGFR wild-type and overexpression) were used to test whether celastrol could overcome primary afatinib resistance through paraptosis induction. The synergistic effect of celastrol and afatinib on survival inhibition of the NSCLC cells was evaluated by CCK-8 assay and isobologram analysis. The paraptosis and its modulation were assessed by light and electron microscopy, Western blot analysis, and immunofluorescence. Xenografts models were established to investigate the inhibitory effect of celastrol plus afatinib on the growth of the NSCLC tumors in vivo. Results showed that celastrol acted synergistically with afatinib to suppress the survival of H23 and H292 cells by inducing paraptosis characterized by extensive cytoplasmic vacuolation. This process was independent of apoptosis and not associated with autophagy induction. Afatinib plus celastrol-induced cytoplasmic vacuolation was preceded by endoplasmic reticulum stress and unfolded protein response. Accumulation of intracellular reactive oxygen species and mitochondrial Ca2+ overload may be initiating factors of celastrol/afatinib-induced paraptosis and subsequent cell death. Furthermore, Celastrol and afatinib synergistically suppressed the growth of H23 cell xenograft tumors in vivo. The data indicate that a combination of afatinib and celastrol may be a promising therapeutic strategy to surmount intrinsic afatinib resistance in NSCLC cells.

Mechanisms of metformin inhibiting cancer invasion and migration.

Cancer currently ranks among the leading causes of death globally. Cancer invasion and metastasis transform locally grown cancers to a systemic and life-threatening disease, which accounts for the most significant challenge in cancer treatment. Recent studies showed that Metformin, the most commonly used first-line oral drug for the treatment of type 2 diabetes (T2DM), could prevent and treat various cancers. Moreover, multiple evidence suggested that metformin inhibited cancer invasion and metastasis, which could improve the prognosis of cancer patients administrated with metformin. To better understand the anti-cancer role of metformin, the present review summarized the potential mechanisms of inhibiting cancer invasion and metastasis by metformin, including AMPK signaling pathway, EMT signaling pathway, epigenetic modification and so on. However, multiple problems remain unresolved and more clinical trials are needed to prove the inhibition of cancer invasion and metastasis by metformin.

PARP inhibitor resistance: the underlying mechanisms and clinical implications.

Due to the DNA repair defect, BRCA1/2 deficient tumor cells are more sensitive to PARP inhibitors (PARPi) through the mechanism of synthetic lethality. At present, several PAPRi targeting poly (ADP-ribose) polymerase (PARP) have been approved for ovarian cancer and breast cancer indications. However, PARPi resistance is ubiquitous in clinic. More than 40% BRCA1/2-deficient patients fail to respond to PARPi. In addition, lots of patients acquire PARPi resistance with prolonged oral administration of PARPi. Homologous recombination repair deficient (HRD), as an essential prerequisite of synthetic lethality, plays a vital role in killing tumor cells. Therefore, Homologous recombination repair restoration (HRR) becomes the predominant reason of PARPi resistance. Recently, it was reported that DNA replication fork protection also contributed to PARPi resistance in BRCA1/2-deficient cells and patients. Moreover, various factors, such as reversion mutations, epigenetic modification, restoration of ADP-ribosylation (PARylation) and pharmacological alteration lead to PARPi resistance as well. In this review, we reviewed the underlying mechanisms of PARP inhibitor resistance in detail and summarized the potential strategies to overcome PARPi resistance and increase PARPi sensitivity.

Potential use of actigraphy to measure sleep in monkeys: comparison with behavioral analysis from videography.

Sleep is indispensable for human health, with sleep disorders initiating a cascade of negative consequences. As our closest phylogenetic relatives, non-human primates (NHPs) are invaluable for comparative sleep studies and exhibit tremendous potential for improving our understanding of human sleep and related disorders. Previous work on measuring sleep in NHPs has mostly used electroencephalography or videography. In this study, simultaneous videography and actigraphy were applied to observe sleep patterns in 10 cynomolgus monkeys ( Macaca fascicularis) over seven nights (12 h per night). The durations of wake, transitional sleep, and relaxed sleep were scored by analysis of animal behaviors from videography and actigraphy data, using the same behavioral criteria for each state, with findings then compared. Here, results indicated that actigraphy constituted a reliable approach for scoring the state of sleep in monkeys and showed a significant correlation with that scored by videography. Epoch-by-epoch analysis further indicated that actigraphy was more suitable for scoring the state of relaxed sleep, correctly identifying 97.57% of relaxed sleep in comparison with video analysis. Only 34 epochs (0.13%) and 611 epochs (2.30%) were differently interpreted as wake and transitional sleep compared with videography analysis. The present study validated the behavioral criteria and actigraphy methodology for scoring sleep, which can be considered as a useful and a complementary technique to electroencephalography and/or videography analysis for sleep studies in NHPs.

Increased attention to snake images in cynomolgus monkeys: an eye-tracking study.

Previous studies have revealed faster detection of snake images in humans and non-human primates (NHPs), suggesting automatic detection of evolutionary fear-relevant stimuli. Furthermore, human studies have indicated that general fear-relevance rather than evolutionary relevance is more effective at capturing attention. However, the issue remains unclarified in NHPs. Thus, in the present study, we explored the attentional features of laboratory-reared monkeys to evolutionary and general fear-relevant stimuli (e.g., images of snakes, capturing gloves). Eye-tracking technology was utilized to assess attentional features as it can provide more accurate latency and variables of viewing duration and frequency compared with visual search task (VST) and response latency adopted in previous studies. In addition, those with autism spectrum disorder (ASD) show abnormal attention to threatening stimuli, including snake images. Rett syndrome (RTT) is considered a subcategory of ASD due to the display of autistic features. However, the attentional features of RTT patients or animal models to such stimuli remain unclear. Therefore, we also investigated the issue in MECP2 gene-edited RTT monkeys. The influence of different cognitive loads on attention was further explored by presenting one, two, or four images to increase stimulus complexity. The eye-tracking results revealed no significant differences between RTT and control monkeys, who all presented increased viewing (duration and frequency) of snake images but not of aversive stimuli compared with control images, thus suggesting attentional preference for evolutionary rather than general fear-relevant visual stimuli. Moreover, the preference was only revealed in visual tasks composed of two or four images, suggesting its cognitive-load dependency.

[Association of RAS mutations in circulating cell-free DNA in the plasma with clinicopathological features of colorectal cancer].

OBJECTIVE: To detect RAS mutations in the circulating cell-free DNA (cfDNA) in the plasma and explore the their correlation with the clinicopathological features in patients with colorectal cancer. METHODS: Real-time PCR was used to detect RAS mutations in plasma cfDNA and matched tumor tissue DNA samples from 71 colorectal cancer patients. The correlation of RAS mutations with the clinicopathological features of the patients were analyzed. RESULTS: Of the 71 patients with colorectal cancer, 23 (32.39%) showed RAS mutations in the cfDNA and 36 (50.7%) showed RAS mutations in tumor tissue DNA, with a concordance rate of 76.06% in the results between the two samples (Kappa=0.523). RAS mutations in the cfDNA were not related to the patients' age (P=0.072), gender (P=0.320), tumor stage (IVa and IVb, P=0.450), primary tumor position (P=0.324), lung metastasis (P=0.237), CEA level (P=0.284) or CA199 level (P=0.427). The positivity rate of RAS mutations in plasma cfDNA was significantly higher in patients with liver metastasis than those without liver metastasis (P=0.045). CONCLUSION: Plasma cfDNA can be a reliable source of diagnostic DNA to replace the tumor tissue DNA for diagnosis of RAS mutations. RAS mutations in plasma cfDNA occur more frequently in colorectal cancer patients with liver metastasis.

Co-inhibition of pol θ and HR genes efficiently synergize with cisplatin to suppress cisplatin-resistant lung cancer cells survival.

Cisplatin exert its anticancer effect by creating intrastrand and interstrand DNA cross-links which block DNA replication and is a major drug used to treat lung cancer. However, the main obstacle of the efficacy of treatment is drug resistance. Here, we show that expression of translesion synthesis (TLS) polymerase Q (POLQ) was significantly elevated by exposure of lung cancer cells A549/DR (a cisplatin-resistant A549 cell line) to cisplatin. POLQ expression correlated inversely with homologous recombination (HR) activity. Co-depletion of BRCA2 and POLQ by siRNA markedly increased sensitivity of A549/DR cells to cisplatin, which was accompanied with impairment of double strand breaks (DSBs) repair reflected by prominent cell cycle checkpoint response, increased chromosomal aberrations and persistent colocalization of p-ATM and 53BP1 foci induced by cisplatin. Thus, co-knockdown of POLQ and HR can efficiently synergize with cisplatin to inhibit A549/DR cell survival by inhibiting DNA DSBs repair. Similar results were observed in A549/DR cells co-depleted of BRCA2 and POLQ following BMN673 (a PARP inhibitor) treatment. Importantly, the sensitization effects to cisplatin and BMN673 in A549/DR cells by co-depleting BRCA2 and POLQ was stronger than those by co-depleting BRCA2 and other TLS factors including POLH, REV3, or REV1. Our results indicate that there is a synthetic lethal relationship between pol θ-mediated DNA repair and HR pathways. Pol θ may be considered as a novel target for lung cancer therapy.

The functional status of DNA repair pathways determines the sensitization effect to cisplatin in non-small cell lung cancer cells.

PURPOSE: Cisplatin can cause a variety of DNA crosslink lesions including intra-strand and inter-strand crosslinks (ICLs), which are associated with the sensitivity of cancer cells to cisplatin. Here, we aimed to assess the contribution of the Fanconi anemia (FA), homologous recombination (HR) and nucleotide excision repair (NER) pathways to cisplatin resistance in non-small cell lung cancer (NSCLC)-derived cells. METHODS: The expression of FA, HR and NER pathway-associated genes was assessed by RT-qPCR and Western blotting. siRNAs were used to knock down the expression of these genes. CCK-8 and flow cytometry assays were used to assess the viability and apoptotic rate of NSCLC-derived cells, respectively. Immunofluorescence and alkaline comet assays were used to assess the repair of ICLs. RESULTS: We found that acquired cisplatin-resistant NSCLC-derived A549/DR cells exhibited markedly enhanced FA and HR repair pathway capacities compared to its parental A549 cells and another independent NSCLC-derived cell line, Calu-1, which possesses a moderate innate resistance to cisplatin. siRNA-mediated silencing of the FA-associated genes FANCL and RAD18 and the HR-associated genes BRCA1 and BRCA2 significantly potentiated the sensitivity of A549/DR cells to cisplatin compared to A549 and Calu-1 cells, suggesting that the acquired cisplatin resistance in A549/DR cells may be attributed to enhanced FA and HR pathway capacities responsible for ICL repair. Although we found that expression knockdown of the NER-associated genes XPA and ERCC1 sensitized the three NSCLC-derived cell lines to cisplatin, the sensitization effect was more significant in Calu-1 cells than in A549 and A549/DR cells, implying that the innate cisplatin resistance in Calu-1 cells may result from an increased NER activity. CONCLUSIONS: Our results indicate that the functional status of DNA repair pathways determine the sensitivity of NSCLC cells to cisplatin. Direct targeting of the pathway that is involved in cisplatin resistance may be an effective strategy to surmount cisplatin resistance in NSCLC.

RNA interferences targeting the Fanconi anemia/BRCA pathway upstream genes reverse cisplatin resistance in drug-resistant lung cancer cells.

BACKGROUND: Cisplatin is one of the most commonly used chemotherapy agent for lung cancer. The therapeutic efficacy of cisplatin is limited by the development of resistance. In this study, we test the effect of RNA interference (RNAi) targeting Fanconi anemia (FA)/BRCA pathway upstream genes on the sensitivity of cisplatin-sensitive (A549 and SK-MES-1) and -resistant (A549/DDP) lung cancer cells to cisplatin. RESULT: Using small interfering RNA (siRNA), knockdown of FANCF, FANCL, or FANCD2 inhibited function of the FA/BRCA pathway in A549, A549/DDP and SK-MES-1 cells, and potentiated sensitivity of the three cells to cisplatin. The extent of proliferation inhibition induced by cisplatin after knockdown of FANCF and/or FANCL in A549/DDP cells was significantly greater than in A549 and SK-MES-1 cells, suggesting that depletion of FANCF and/or FANCL can reverse resistance of cisplatin-resistant lung cancer cells to cisplatin. Furthermore, knockdown of FANCL resulted in higher cisplatin sensitivity and dramatically elevated apoptosis rates compared with knockdown of FANCF in A549/DDP cells, indicating that FANCL play an important role in the repair of cisplatin-induced DNA damage. CONCLUSION: Knockdown of FANCF, FANCL, or FANCD2 by RNAi could synergize the effect of cisplatin on suppressing cell proliferation in cisplatin-resistant lung cancer cells through inhibition of FA/BRCA pathway.

Curcumin reverses cisplatin resistance in cisplatin-resistant lung caner cells by inhibiting FA/BRCA pathway.

Cisplatin (DDP) is the most widely used chemotherapy agent for treatment of malignancies including lung cancer. However, the effectiveness of DDP is often weakened by acquired resistance of tumor cells. DDP kills cancer cells primarily by creating intrastrand and interstrand DNA cross-links, which block DNA replication. The Fanconi anemia (FA)/BRCA pathway is a DNA cross-link damage repair pathway, which regulates cellular resistance to DNA cross-link agents, such as DDP. Some study has shown that natural compound curcumin sensitize human ovarian and breast cancer cells to DDP. However, whether curcumin may reverse resistance to DDP in DDP-resistant lung cancer cells has not been understood. In this study, we showed that curcumin enhanced the proliferation inhibitory effect of DDP and promote DDP-induced apoptosis in A549/DDP cells (DDP-resistant lung adenocarcinoma cells). Moreover, we observed that FA/BRCA pathway DNA damage repair processes, such as DDP-induced FANCD2 monoubiquitination and nuclear foci formation were downregulated in the presence of curcumin, suggesting that curcumin enhanced sensitivity to DDP in A549/DDP cells through the inhibition of FA/BRCA pathway. Furthermore, the calculation of q value and apoptosis analyses revealed that curcumin in combination with DDP could exert a synergistic cytotoxic effect in A549/DDP cells, further demonstrating that curcumin can reverse cisplatin resistance of A549/DDP cells. In conclusion, by suppressing the FA/BRCA pathway DNA repair, curcumin potentiates DDP-induced proliferation inhibitory effect and apoptosis in A549/DDP cell, indicating that curcumin may serve as a chemosensitizer to cross-link-inducing anticancer drugs DDP.

Structure and function of IQ-domain GTPase-activating protein 1 and its association with tumor progression (Review).

IQ-domain GTPase-activating proteins (IQGAPs) are evolutionary conserved multidomain proteins that are found in numerous organisms, from yeast to mammals. To date, three IQGAP proteins have been identified in humans, of which IQGAP1 is the best characterized. As a scaffold protein, IQGAP1 contains multiple protein-interacting domains, which modulate binding to target proteins. Recent mounting studies demonstrated a role for IQGAP1 in tumor progression, supported by the altered expression and subcellular distribution of IQGAP1 in tumors. The contribution of IQGAP1 to tumor progression appears to involve a complex interplay of cell functions by integrating diverse signal transduction pathways and coordinating activities, such as cell adhesion, migration, invasion, proliferation and angiogenesis.

Prognostic value of EpCAM/MUC1 mRNA-positive cells in non-small cell lung cancer patients.

The aim of this study was to assess the prognostic value of EpCAM/MUC1 mRNA-positive circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). The presence of EpCAM/MUC1 mRNA-positive CTCs was evaluated in 74 NSCLC patients before the initiation of any therapy, from which 61 patients with surgical resection of tumor were also evaluable for EpCAM/MUC1 mRNA-positive CTC analysis after surgery, by quantitative real-time PCR assay. Sixty patients with benign lung disease (BLD) entered this study as controls. The results showed that blood levels of EpCAM and MUC1 mRNA in NSCLC patients before and after surgery were significantly higher than those in BLD patients (P = 0.001 and P = 0.015, respectively, for EpCAM; P = 0.003 and P = 0.026, respectively, for MUC1), and the levels of the two gene mRNA in NSCLC patients significantly decreased after surgery (P = 0.025 and P = 0.033, respectively). Disease recurrence significantly increased in NSCLC patients with EpCAM/MUC1 mRNA-positive CTC preoperation and postoperation (P = 0.004 and P = 0.001, respectively). Disease-free survival and overall survival significantly reduced in patients with EpCAM/MUC1 mRNA-positive CTC preoperation and postoperation (P = 0.012 and P = 0.002, respectively, for preoperation; both P < 0.001 for postoperation). Multivariate analysis demonstrated that the presence of EpCAM/MUC1 mRNA-positive CTCs before and after surgery was an independent factor associated with disease recurrence. In conclusion, the detection of EpCAM/MUC1 mRNA-positive CTCs in the blood before and after surgery is useful for predicting a poor prognosis in NSCLC patients who undergo curative surgery.

CK-19 mRNA-positive cells in peripheral blood predict treatment efficacy and survival in small-cell lung cancer patients.

Small-cell lung caner (SCLC) is the most aggressive form of lung cancer. The aim of this study was to investigate whether the presence of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTCs) predicts treatment response, progression-free survival (PFS), and overall survival (OS) in SCLC patients who received standard therapy. Fifty-five SCLC patients were enrolled in this single-center prospective study. CK-19 mRNA-positive CTCs in blood samples were detected using real-time quantitative-PCR assay before the initiation of chemotherapy (B0) and after one chemotherapy cycle (B1) and three chemotherapy cycles (B3). The association with known prognostic factors and the effect of CK-19 mRNA-positive CTCs on patients' prognosis were analyzed. Patients with positivity for CK-19 mRNA-positive CTCs at B0, B1, and B3 time points had shorter PFS and OS compared with patients without (P = 0.014 and P = 0.01, respectively, at B0; P = 0.008 and P = 0.002, respectively, at B1; P = 0.003 and P = 0.001, respectively, at B3). Conversion of initial positivity for CK-19 mRNA-positive CTCs to negativity at B1 and B3 time points was associated with longer PFS and OS compared with patients with persistent positivity at three time points (P = 0.008 and P = 0.010, respectively). Multivariate analysis demonstrated that the presence of CK-19 mRNA-positive CTCs at B0, B1, and B3 time points remained strong predictors of PFS and OS after adjustment for clinically significant factors. In conclusion, detection of CK-19 mRNA-positive CTCs before and during chemotherapy is an accurate indication of subsequent disease progression and mortality for SCLC patients.

Serum HER 2 extracellular domain level is correlated with tissue HER 2 status in metastatic gastric or gastro-oesophageal junction adenocarcinoma.

BACKGROUND: To explore the association between serum human epidermal growth factor receptor 2 (HER 2) extracellular domain (ECD) levels and tissue HER 2 status in metastatic gastric cancer. PATIENTS AND METHODS: HER 2 status was retrospectively analyzed in 219 advanced gastric or gastroesophageal junction (GEJ) patients. Serum HER 2 ECD was measured by chemiluminescent assay and tissue HER 2 was assessed by fluorescent in situ hybridisation (FISH) and immunohistochemistry (IHC) assay. RESULTS: Significant associations were found between serum HER 2 ECD levels and tissue HER 2 status. Twenty-four patients had HER 2 ECD levels >16.35 ng/mL, which has a sensitivity of 51.4% and a specificity of 97.3% to predict tissue HER 2 status. When the cut-off value was increased to 22 ng/mL, then all 12 patients with serum HER 2 ECD levels>22 ng/mL were tissue HER 2 positive, corresponding to a specificity of 100% and a sensitivity of 32.4%. High serum HER 2 ECD levels were strongly associated with the intestinal histological type (Lauren's classification), liver metastasis, multiple metastasis (>2) and increased LDH levels, but not with overall survival. CONCLUSIONS: The high specificity of the serum HER 2 ECD assay in predicting tissue HER 2 status suggests its potential as a surrogate marker of the HER 2 status in gastric cancer.

Type II, but not type I, cGMP-dependent protein kinase reverses bFGF-induced proliferation and migration of U251 human glioma cells.

Previous data have shown that the type II cGMP­dependent protein kinase (PKG II) inhibits the EGF­induced MAPK signaling pathway. In order to thoroughly investigate PKG, it is necessary to elucidate the function of another type of PKG, PKG I. The aim of this study was to investigate the possible inhibitory effect of PKG II and PKG I activity on the basic fibroblast growth factor (bFGF)­induced proliferation and migration of U251 human glioma cells and the possible underlying mechanisms. U251 cells were infected with adenoviral constructs encoding cDNA of PKG I (Ad­PKG I) or PKG II (Ad­PKG II) to increase the expression levels of PKG I or PKG II and then treated with 8­Br­cGMP and 8­pCPT­cGMP, respectively, to activate the enzyme. An MTT assay was used to detect the proliferation of the U251 cells. The migration of the U251 cells was analyzed using a Transwell migration assay. Western blot analysis was used to detect the phosphorylation/activation of the fibroblast growth factor receptor (FGFR), MEK and ERK and the nuclear distribution of p-ERK. The results showed that bFGF treatment increased the proliferation and migration of U251 cells, accompanied by increased phosphorylation of FGFR, MEK and ERK. Furthermore, the nuclear distribution of p-ERK increased following bFGF treatment. Increasing the activity of PKG II through infection with Ad-PKG II and stimulation with 8-pCPT-cGMP significantly attenuated the aforementioned effects of the bFGF treatment, while increased PKG I activity did not inhibit the effects of bFGF treatment. These data suggest that increased PKG II activity attenuates bFGF­induced proliferation and migration by inhibiting the MAPK/ERK signaling pathway, whereas PKG I does not.

Endogenous cGMP-dependent protein kinase reverses EGF-induced MAPK/ERK signal transduction through phosphorylation of VASP at Ser239.

In our previous study, we demonstrated that type II cGMP-dependent protein kinase (PKG II) was expressed at lower levels in different human cancer cell lines and that exogenous PKG II inhibited epidermal growth factor (EGF)-induced MAPK/ERK signaling. In order to investigate its functions further in this signaling pathway, it is necessary to elucidate whether endogenous PKG has the same effect or not. This study aimed to investigate the possible inhibitory effect of endogenous PKG activity on EGF-induced MAPK/ERK signal transduction in human lung cancer cells and its mechanism. Human small cell lung carcinoma cells (SCLCs) were treated with the PKG-selective cGMP analog 8-pCPT-cGMP to activate endogenous PKG, EGF and cGMP followed by EGF, respectively. The results showed that increased endogenous PKG activity inhibited the EGF-induced phosphorylation of the epidermal growth factor receptor (EGFR) and the binding between Sos1 and Grb2. In addition, EGF-triggered Ras activation was reversed by increased endogenous PKG activity. While the EGF-induced phosphorylation of MEK and ERK were inhibited by increased endogenous PKG activity, there was a significant increase of phosphorylated vasodilator-stimulated phosphoprotein (p-VASP) at Ser239. Furthermore, we investigated whether endogenous PKG exerted its effects on EGF-induced MAPK/ERK signaling through phosphorylation of VASP at Ser239. Downregulation of the levels of p-VASP Ser239 by point mutation blocked the effects of endogenous PKG on EGF-induced MAPK/ERK signal transduction. The data shown here suggest that endogenous PKG reverses the EGF-induced MAPK/ERK signaling pathway by phosphorylating VASP at Ser239.