Case report: 177Lu DOTA-TATE: a new scheme for the treatment of prostate neuroendocrine cancer.

Background: Most instances of small cell carcinoma originate from the lungs, while the gastrointestinal tract serves as a secondary site. Only a minuscule proportion of cases manifest within the urogenital system. Prostate small cell carcinoma (SCCP) represents an exceedingly uncommon pathological subtype within the realm of prostate cancer, displaying significant rarity in clinical settings. This scarcity has resulted in a paucity of adequate foundational and clinical research for SCCP treatment. While investigations have unveiled a certain therapeutic efficacy of radiotherapy and chemotherapy for SCCP, clinical practice has revealed suboptimal treatment outcomes. We hereby present a case report detailing the utilization of 177Lu-DOTA-TATE in the treatment of SCCP, aiming to investigate the therapeutic efficacy of 177Lu-DOTA-TATE for SCCP. Case presentation: A male patient in his 80s presented with elevated prostate-specific antigen (PSA) levels and underwent a biopsy that revealed prostate adenocarcinoma. The patient received CAB (bicalutamide + goserelin) therapy. One year later, disease progression was detected, and a second biopsy confirmed the presence of prostate small cell carcinoma. Following the diagnosis of prostate small cell carcinoma, the patient underwent two cycles of 177Lu-DOTA-TATE treatment. Subsequent to the treatment, the original lesions showed shrinkage, metastatic lesions disappeared, and there was significant improvement, approaching complete remission. Conclusion: SCCP exhibits a high degree of malignancy and aggressive invasiveness, currently lacking effective therapeutic modalities. The treatment course of this patient serves as compelling evidence for the efficacy of 177Lu-DOTA-TATE in managing SCCP, thereby opening new avenues for future SCCP treatments.

Role of N6-methyladenosine RNA modification in gastric cancer.

N6-methyladenosine (m6A) RNA methylation is the most prevalent internal modification of mammalian messenger RNA. The m6A modification affects multiple aspects of RNA metabolism, including processing, splicing, export, stability, and translation through the reversible regulation of methyltransferases (Writers), demethylases (Erasers), and recognition binding proteins (Readers). Accumulating evidence indicates that altered m6A levels are associated with a variety of human cancers. Recently, dysregulation of m6A methylation was shown to be involved in the occurrence and development of gastric cancer (GC) through various pathways. Thus, elucidating the relationship between m6A and the pathogenesis of GC has important clinical implications for the diagnosis, treatment, and prognosis of GC patients. In this review, we evaluate the potential role and clinical significance of m6A-related proteins which function in GC in an m6A-dependent manner. We discuss current issues regarding m6A-targeted inhibition of GC, explore new methods for GC diagnosis and prognosis, consider new targets for GC treatment, and provide a reasonable outlook for the future of GC research.

Exposure to Commonly Used Drugs and the Risk of Gastric Cancer: An Umbrella Review of Meta-Analyses.

Recently, attention has been paid to some medications and gastric cancer (GC) risk. This review aimed to evaluate associations between commonly used drugs and GC risk and to grade evidence from published systematic reviews and meta-analyses. This umbrella review was registered in PROSPERO (CRD42022320276). The systematic reviews and meta-analyses of observational studies were retrieved by searching Embase, PubMed, and Web of Science. The evidence strength of commonly used drugs and GC risk was categorized into four grades: weak, suggestive, highly suggestive, and strong. Of 19 associations between commonly used drugs and GC risk and its subtypes, none was supported by convincing or highly suggestive evidence. The risk of GC related to non-steroidal anti-inflammatory drugs (NSAIDs), non-aspirin NSAIDs, and acid-suppressive drugs, as well as the risk of non-cardia GC related to NSAIDs and aspirin, was supported by suggestive evidence. The results showed that a reduced GC risk was associated with two drug types (NSAIDs and non-aspirin NSAIDs), and an increased GC risk was associated with acid-suppressing drugs at the suggestive evidence level. Moreover, NSAIDs and aspirin reduced non-cardia GC risk as supported by suggestive evidence. However, the evidence supporting statins or metformin in reducing GC risk was weak, and thus future studies are required to clarify these associations.

Exosomal circRNAs: A key factor of tumor angiogenesis and therapeutic intervention.

Over the last few decades, our understanding of the molecular mechanisms underlying tumor angiogenesis has advanced at a significant pace and the clinical translation of these mechanisms has benefited millions of patients. However, limited efficacy and the rapid expansion of drug resistance remain unresolved issues. Recent studies in both preclinical and clinical settings have revealed that circRNAs, as a novel identified non-coding RNA can mediate intercellular communication and regulate the microenvironment within tumors after being selectively packaged, secreted, and transmitted via exosomes. This review aims to provide a comprehensive understanding of how exosomal circRNAs orchestrate inducers and inhibitors of angiogenesis, including their functions, molecular mechanisms, and potential roles as diagnostic biomarkers and therapeutic targets. Finally, we discuss the technological advances in exosome functionalization and exosome-mimetic nanovesicles intending to improve the clinical translation of exosomal circRNAs.

Bone flare after initiation of novel hormonal therapy in patients with metastatic hormone-sensitive prostate cancer: A case report.

BACKGROUND: The 2020 European Association of Urology prostate cancer guidelines recommend androgen deprivation therapy (ADT) in combination with apalutamide and enzalutamide, a new generation of androgen receptor antagonists, as first-line therapy. A decrease in prostate-specific antigen (PSA) levels may occur in the early stages of novel hormonal therapy; however, radionuclide bone imaging may suggest disease progression. During follow-up, PSA, radionuclide bone imaging, and prostate-specific membrane antigen (PSMA) positron emission tomography - computed tomography (PET-CT) are needed for systematic evaluation. CASE SUMMARY: We admitted a 56-year-old male patient with metastatic hormone-sensitive prostate cancer. Initial radionuclide bone imaging, magnetic resonance imaging (MRI), and PSMA PET-CT showed prostate cancer with multiple bone metastases. Ultrasound-guided needle biopsy of the prostate revealed a poorly differentiated adenocarcinoma of the prostate with a Gleason score: 5+4 = 9. The final diagnosis was a prostate adenocarcinoma (T4N1M1). ADT with novel hormonal therapy (goseraline sustained-release implant 3.6 mg monthly and apalutamide 240 mg daily) was commenced. Three months later, radionuclide bone imaging and MRI revealed advanced bone metastasis. However, PSMA PET-CT examination showed a significant reduction in PSMA aggregation on the bone, indicating improved bone metastases. Considering that progressive decrease in the presenting lumbar pain, treatment strategies were considered to be effective. CONCLUSION: ADT using novel hormonal therapy is effective for treating patients with prostate adenocarcinoma. Careful evaluation must precede treatment plan changes.

RIP2 Knockdown Attenuates Vascular Smooth Muscle Cells Activation via Negative Regulating Myocardin Expression.

BACKGROUND: RIP2 is an adaptor protein contributing to the activation of nuclear factor-κB induced by TNF receptor-associated factor (TRAF) and nucleotide oligomerization domain (NOD)-dependent signaling implicated in innate and adaptive immune response. Beyond regulation of immunity, we aimed to elucidate the role of RIP2 in vascular smooth muscle cell (VSMC) phenotypic modulation. METHODS AND RESULTS: In the current study, we observed that RIP2 showed an increased expression in VSMCs with PDGF-BB stimulation in a dose-dependent manner. Knockdown of RIP2 expression mediated by adenovirus dramatically accelerated the expression of VSMC-specific differentiation genes induced by PDGF-BB. Silencing of RIP2 inhibited proliferative and migratory ability of VSMCs. Additionally, we demonstrated that RIP2 knockdown can promoted myocardin expression. Furthermore, RIP2 inhibition also can attenuate the formation of intimal hyperplasia. CONCLUSIONS: These findings suggested that RIP2 played an important role in regulation of VSMCs differentiation, migration, and proliferation that may due to affect myocardin expression. Our results indicated that RIP2 may be a novel therapeutic target for intimal hyperplasia.

OVOL2 inhibits macrophage M2 polarization by regulating IL-10 transcription, and thus inhibits the tumor metastasis by modulating the tumor microenvironment.

Invasion and metastasis of breast cancer cells is an important cause of death in breast cancer patients. In the tumor microenvironment, M2 polarization of macrophages can promote the invasion and metastasis of tumor cells. OVOL2 is an evolutionarily conserved transcription regulator, but its effect in macrophages has not been described previously. The aim of this study was to investigate the effects of OVOL2 on macrophage polarity and the role of these effects in the tumor metastasis. We found that overexpression of OVOL2 in macrophages significantly inhibited M2 polarization and thus inhibits breast cancer metastasis. We propose a novel mechanism in which OVOL2 inhibits M2 polarization of macrophages and thus reduces their ability to induce invasion and metastasis of breast cancer. By shedding new light on the regulation of metastasis in cancers, our study provides a new strategy for the targeted therapy of cancer.

Giant Cell Tumors of Bone in Patients Aged 18 Years Old or Younger: Imaging Features and Tumor Characteristics.

OBJECTIVE: The majority of giant cell tumors of bone (GCTB) occur in adult patients, especially between the ages of 20 and 40. This study aims to investigate the imaging features of GCTBs in pediatric patients and compare their characteristics with adult cases. METHODS: Fifty-seven cases of patients aged 18 years old or younger were retrospectively analyzed, accounting for 12.8% of GCTBs in the First Affiliated Hospital of Zhengzhou University from 2001 to 2019. One hundred twenty-six adult patients (19 years of age and older) with GCTB occurring in long tubular bones were also included in this study. The following clinical information was identified from the medical records: age, sex, and follow-up data. Imaging features were reviewed by two musculoskeletal radiologists. Patient characteristics and imaging features between the two groups were compared. RESULTS: A total of 57 patients (32 females, 25 males) were included in the study. The patients' ages ranged from 9 to 18 (median = 17 y). The majority of tumors occurred in tubular bones (n = 38, 66.7%) and the pelvis (n = 8, 14.0%). Imaging features were identified in GCTB cases occurring in the long tubular bones. Compared with adult GCTB patients, pediatric GCTB patients had a larger superior-inferior (SI) diameter (P = 0.005) and smaller left-to-right diameter/SI diameter ratio (P = 0.001). Epiphyseal involvement was relatively less common in pediatric patients with GCTBs than in adult patients (P = 0.009). The median age of patients without epiphyseal involvement was lower than the median age of patients with epiphyseal involvement (11 vs 17 y). CONCLUSION: GCTB in the pediatric age group is rare. This study has found that, in pediatric patients with GCTBs, the epiphysis is relatively less involved, and the tumor is more likely to grow longitudinally. These findings are helpful in the diagnosis of GCTBs in the pediatric population.

Effects of Apolipoprotein Ε Îµ4 allele on early postoperative cognitive dysfunction after anesthesia.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is one of the main causes of morbidity after noncardiac surgery; however, the pathogenic mechanisms of POCD have remained unclear until now. In this study, we performed a pilot study to investigate the association between apolipoprotein E (ApoE) ε4 and POCD in older patients undergoing intravenous anesthesia (IVA) and inhalation anesthesia (IAA). METHODS: In total, 180 patients from Shenzhen People's Hospital were recruited and randomly divided into an IVA group and an IAA group. The IVA group and IAA group received propofol and sevoflurane treatment, respectively. Within 7 days after surgery, the mini-mental state examination (MMSE) was used daily to assess the cognitive function of both groups of patients. The genotypes of the ApoE gene were detected using the restriction fragment length polymorphism technique. In addition, the serum levels of (soluble protein-100ß) S­100ß and (Interleukin- 6) L­6 were also analyzed. RESULTS: Compared to the preoperative and IVA groups, the MMSE score in the IAA group significantly decreased at 3 days after surgery. Furthermore, the IAA group had a higher percentage of patients who scored less than 25 points than the IVA group at 3 days after surgery. The decrease in the MMSE score was closely related to the ApoE ε4 allele in the IAA group, but this correlation was not observed in the IVA group. The levels of S­100ß and IL­6 were increased sharply in patients with the ε4/ε4 genotype who received IAA compared with IVA at 1 day after surgery. CONCLUSION: The results of the study indicated that the ApoΕ Îµ4/ε4 genotype was a risk factor for early POCD in older patients undergoing sevoflurane anesthesia.

Attenuated macrophage activation mediated by microRNA-183 knockdown through targeting NR4A2.

Atherosclerosis is considered a chronic inflammatory disease, and macrophages function as important mediators in the development of atherogenesis. MicroRNA (miR)-183 is a small non-coding RNA that acts as a novel tumor suppressor and has recently been proposed to affect cardiac hypertrophy. However, the exact role and underlying mechanism of miR-183 in macrophage activation remain unknown. In the present study, miR-183 showed upregulated expression in atheromatous plaques and in bone marrow-derived macrophages (BMDMs) subjected to stimulation with oxidized low-density lipoproteins. Using a miR-183 loss-of-function strategy, it was demonstrated that miR-183 knockdown significantly increased resolving M2 macrophage marker expression but decreased proinflammatory M1 macrophage marker expression, as well as attenuated NF-κB activation. Moreover, decreased foam-cell formation accompanied by upregulation of genes involved in cholesterol efflux and downregulation of genes implicated in cholesterol influx was found in BMDMs transfected with a miR-183 inhibitor. Mechanistically, macrophage activation mediated by miR-183 silencing was partially attributed to direct upregulation of NR4A2 expression in BMDMs. Thus, the present study suggests that neutralizing miR-183 may be a potential therapeutic strategy for the treatment of atherosclerosis.

pH-Sensitive Black Phosphorous-Incorporated Hydrogel as Novel Implant for Cancer Treatment.

In this study, black phosphorus nanosheets (BPNSs) were incorporated into a hydrogel formed from dibenzaldehyde-functionalized polymer (DF-PEG) and polyaspartylhydrazide (PAHy) polymer to create an injectable and pH-sensitive DF-PEG-PAHy/BPNSs hydrogel, which can be used as a smart depot for synergistic chemo-photothermal cancer therapy. The DF-PEG-PAHy/BPNSs hydrogel exhibited excellent gelation characteristics, pH sensitivity, and near-infrared responsiveness. The nanocomposite hydrogel provided controlled drug release and near-infrared irradiation speeded up release of drug from the hydrogel because of the photothermal effect of the BPNSs. Cytotoxicity tests confirmed that the hydrogel has good biocompatibility and exerts its photothermal effect in vitro. Antitumor tests in mice demonstrated the capacity of DF-PEG-PAHy/BPNSs hydrogel for synergistic chemo-photothermal therapy in vivo. The hydrogel showed reduced adverse effects because of stable drug release in the tumor area and an efficient photothermal effect. Together, these data demonstrated the potential of DF-PEG-PAHy/BPNSs hydrogel containing a chemotherapy drug to serve as a novel smart delivery system for combined chemo-photothermal cancer therapy.

[Simultaneous Removal of Polychlorinated Dibenzo-p-dioxins/dibenzofurans, Polychlorinated Biphenyls, and Polychlorinated Naphthalenes From Flues Gases From Coke Gas Burning Using Selective Catalytic Reduction Equipment].

The removal efficiencies of typical unintentionally produced persistent organic pollutants (UP-POPs) from flues gases from coke gas burning were obtained using selective catalytic reduction (SCR) equipment installed in a large coking plant. The total congeners of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) in the flue gases at the inlet and outlet of the SCR equipment and the dustfall were analyzed. The results show that the removal efficiency of the total PCDD/Fs was the highest (94.6%). The removal efficiencies of total PCBs and total PCNs were 74.7% and 78.4%, respectively. The homologue profile of UP-POPs in the flue gases at the inlet of the SCR equipment notably differed from that at the outlet. Highly chlorinated UP-POPs predominated over the homologue profile of UP-POPs in the inlet flue gas, while low-chlorinated UP-POPs were predominant in the outlet flue gas. The SCR equipment achieved a better removal efficiency with respect to highly chlorinated UP-POPs. Catalytic reduction and catalytic oxidation degradation are both important mechanisms for the removal of UP-POPs from flue gas using SCR equipment.

Target-controlled infusion of propofol and remifentanil combined with dexmedetomidine reduces functional endoscopic sinus surgery bleeding.

The aim of the present study was to investigate the effects of target-controlled infusion (TCI) of propofol and remifentanil combined with dexmedetomidine on functional endoscopic sinus surgery (FESS) bleeding and surgical field. 62 patients scheduled to undergo FESS were randomly divided into experimental group (intravenous 0.5 µg kg-1 h-1 dexmedetomidine after 0.5 µg kg-1 bolus within 15 min until the end of surgery) or control group (intravenous saline administration at the same dose). All patients underwent endotracheal intubation under general anesthesia with TCI of propofol and remifentanil for anesthesia induction and maintenance. During anesthesia, arterial pressure (MAP), heart rate (HR), intraoperative propofol and remifentanil dosage and intraoperative blood loss were recorded. Surgeons rated their satisfaction with the surgical field using the Numeric Rating Scale (NRS). Following surgery, visual analog scale (VAS) was assessed. During tracheal intubation and extubation, HR and MAP in the experimental group were significantly lower compared with the control group (P<0.05); HR was also significantly lower compared with the control group throughout surgery (P<0.05). The mean infusion rate of propofol and remifentanil was significantly lower in the experimental group compared with the control group (P=0.001 and P=0.045, respectively). Blood loss in the experimental group was significantly lower compared with the control group (P=0.007). NRS and VAS scores in the experimental group were significantly improved compared with control group (P<0.01). In conclusion, TCI of propofol and remifentanil for FESS combined with dexmedetomidine reduced intraoperative bleeding and improved the quality of surgical field compared with the same procedure without dexmedetomidine. Dexmedetomidine also reduced the increase in MAP and HR during tracheal intubation and extubation, and improved postoperative analgesia quality.

[Correlation of Thrombosis and Prothrombotic State with Coagulation Factor V Gene Polymorphism and APCR. HHcy].

OBJECTIVE: To investigate the correlation of patients with thrombosis or prothrombotic status with hyperhomocysteinemia (HHcy), activated protein C-resistance(APCR) and gene polymorphism of coagulation factor V. METHODS: Three hundred healthy voluteers were selected as controls, 223 cases of thrombosis (80 cases of cerebral infarction of CT, the MI of 82 cases of myocardial infarction, venous thrombosis of VTE 61 cases), 270 cases of patients with prothrombotic state (76 cases of pregnancy disease of PIH, 62 cases of chronic obstructive pulmonary disease (COPD), 60 cases of diabetes(DM) and 72 cases of cancer) were enrolled in this study. The plasma APCR and hyperhomocysteinemia were detected by APTT coagulation method and cycling enzyme method respectively, and restriction fragment length polymorphism(RFLP) were was used to detect the gene polymorphism of FV G1691-A, G1091-C and A1090-G in the patient and control groups. RESULTS: APCR positive rate was 62.29% and 7.33%, and the positive hyperhomocysteinemia accounted for 68.42% and 10.00% respectively in the group of the patients with venous thrombosis and the normal control group. 3 cases of heterozygous FV gene mutations were found in the APCR-positive patients with venous thrombosis. CONCLUSION: HHcy possitive rate of patients with venous thrombosis is signiticantly higher than that in control, the HHcy is one of the important causes resulting in thrombosis, the patients with venous thrombosis have proved to be with APCR, and the possitive APCR may be related with the coagulation factor V gene polymorphism.

The findings of CT and MRI in patients with metanephric adenoma.

BACKGROUND: Metanephric adenoma (MA) is a benign renal tumor that is difficult to distinguish from a malignant tumor via traditional radiography. The diagnosis of MA is often dependent on postsurgical histopathological examination. In the present report, the imaging features of MA on computer tomography (CT) and magnetic resonance imaging (MRI) were retrospectively evaluated. METHODS: Eight MA patients, 17-67 years of age, were pathologically confirmed and recruited between April 2009 and November 2014. Four of the eight patients were female. All patients underwent CT scanning, and one patient underwent MRI scanning. Three patients underwent CTA of the renal arteries. All patients underwent resection surgery (radical nephrectomy in five and nephron-sparing surgery in three patients). RESULTS: The average tumor size was 44.0 ± 23.6 mm. The lesions in 87.5 % cases were located both in the renal cortex and medulla and exhibited exophytic growth. Plain CT showed that MA tumors were solid, and the average CT value was 37.9 ± 6.7 HU. Dynamic contrast-enhanced CT revealed that enhanced degrees of MA tumors in the renal cortex, renal parenchymal, and pelvic phase were all lower than that of normal renal parenchyma. A slight enhancement in the renal cortex phase and an even higher enhancement in the renal parenchymal phase were observed in seven of the cases. Progressive enhancement in the pelvic phase was found in five cases and a slight decreased enhancement in the pelvic phase in two cases. MRI revealed that MA tumor was isointense on T1WI and isointense on T2WI with some slightly hyperintense areas in the center. CTA of the renal arteries revealed the nutrient artery in one patient and no nutrient artery in two. Immunohistochemical experiments demonstrated that most tumor cells were positive for vimentin, CK, and EMA. CONCLUSIONS: MA is a rare benign renal neoplasm. Detailed knowledge of the CT and MRI characteristics of MA plays an important role in MA diagnosis and treatment.

Extended immunologic and genetic lineage of mammary analogue secretory carcinoma of salivary glands.

Mammary analogue secretory carcinoma (MASC) of salivary glands is a newly recognized tumor entity. To explore a more practical and convenient immunohistochemical approach to distinguish MASC from other tumors arising from salivary glands as well as to expand the immunologic and genetic lineage of MASC, we examined 17 MASCs using clinicopathologic, immunohistochemical, and molecular analyses. Eighteen cases of acinic cell carcinoma, 18 cases of adenoid cystic carcinoma, 22 cases of mucoepidermoid carcinoma, and 14 cases of basal cell adenocarcinoma were brought in for comparison. Seventeen MASCs shared similar architectures with not only intraluminal or intracellular secretion but also low-grade vesicular nuclei. In addition, they were all immunoreactive for S-100 and SOX-10, whereas only 3 of 17 demonstrated reactivity for GATA-3 and P63, and 4 of 17 were focally positive for CD117. ETV6 translocation was detected in 10 cases by fluorescence in situ hybridization, whereas intact ETV6 was noted in 2 cases. Our data proposed a combined immunohistochemical panel to distinguish MASC from other tumors arising from salivary glands and expanded the immunologic and genetic lineage of MASC.

Dexmedetomidine alleviates pulmonary edema by upregulating AQP1 and AQP5 expression in rats with acute lung injury induced by lipopolysaccharide.

This study aims to elucidate the mechanisms by which dexmedetomidine alleviates pulmonary edema in rats with acute lung injury induced by lipopolysaccharide (LPS). Male Wistar rats were randomly divided into five groups: normal saline control (NS) group, receiving intravenous 0.9% normal saline (5 mL/kg); LPS group, receiving intravenous LPS (10 mg/kg); small-dose dexmedetomidine (S) group, treated with a small dose of dexmedetomidine (0.5 µg · kg(-1) · h(-1)); medium-dose dexmedetomidine (M) group, treated with a medium dose of dexmedetomidine (2.5 µg · kg(-1) · h(-1)); high-dose dexmedetomidine (H) group, treated with a high dose of dexmedetomidine (5 µg · kg(-1) · h(-1)). The rats were sacrificed 6 h after intravenous injection of LPS or NS, and the lungs were removed for evaluating histological characteristics and determining the lung wet/dry weight ratio (W/D). The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1ß (IL-1ß) in the lung tissues were assessed by enzyme- linked immunosorbent assay (ELISA). The mRNA and protein expression levels of aquaporin-1 (AQP1) and aquaporin-5 (AQP5) were detected by RT-PCR, immunohistochemistry, and Western blotting. The lung tissues from the LPS groups were significantly damaged, which were less pronounced in the H group but not in the small-dose dexmedetomidine group or medium-dose dexmedetomidine group. The W/D and the concentrations of TNF-α and IL-1ß in the pulmonary tissues were increased in the LPS group as compared with those in NS group, which were reduced in the H group but not in S group or M group (P<0.01). The expression of AQP1 and AQP5 was lower in the LPS group than in the NS group, and significantly increased in the H group but not in the S group or M group (P<0.01). Our findings suggest that dexmedetomidine may alleviate pulmonary edema by increasing the expression of AQP-1 and AQP-5.

Notch signaling inhibits the growth of the human chronic myeloid leukemia cell line K562.

Notch signaling functions in the development of some types of leukemia and lymphoma, but the relationship between Notch signaling and chronic myeloid leukemia (CML) remains to be elucidated. In this study, we examined the expression of Notch receptors and ligands in the human CML cell line K562. When the active form of Notch1, the Notch intra-cellular domain (NIC), was over-expressed in K562, the proliferation of K562 was mildly but significantly inhibited, accompanied by increased Hes1 mRNA level. On the other hand, when Notch signaling was attenuated by over-expression of a dominant-negative RBP-J, RBP-J(R218H), in K562 cells, the proliferation of K562 was increased. Moreover, we found that activation of Notch signaling inhibited while repression of Notch signaling promoted the colony-forming activity of K562 cells. We examined cell cycle-related molecules in K562 transfected with NIC or RBP-J(R218H), and found that the protein level of the retinoblastoma gene product (the Rb protein) was induced in K562 expressing NIC, and down-regulated in K562 expressing RBP-J(R218H). These data suggest that the Notch signaling may function as a tumor inhibitor in human CML cells.

Notch activation promotes cell proliferation and the formation of neural stem cell-like colonies in human glioma cells.

Since Notch signaling plays a critical role in stem cells and oncogenesis, we hypothesized that Notch signaling might play roles in cancer stem cells and cancer cells with a stem cell phenotype. In this study, we accessed potential functions of the Notch pathway in the formation of cancer stem cells using human glioma. Using RT-PCR, we found that most human astrogliomas of different grades expressed moderate to high level of Notch receptors and ligands. mRNA of Hes5 but not Hes1, both of which are major downstream molecules of the Notch pathway, was also detected. In human glioma cell lines BT325, U251, SHG-44, and U87, mRNA encoding different types of Notch receptors were detected, but active form of Notch1 (NIC) was only detected in SHG-44 and U87 by Western blot. Interestingly, proliferation of these two glioma cell lines appeared faster than that of the other two lines in which NIC was not detected. We have over-expressed NIC of Notch1 in SHG-44 cells by constitutive transfection to evaluate the effects of Notch signaling on glioma cells. Our results showed that over-expression of NIC in SHG-44 cells promoted the growth and the colony-forming activity of SHG-44 cells. Interestingly, over-expression of NIC increased the formation neurosphere-like colonies in the presence of growth factors. These colonies expressed nestin, and could be induced to cells expressing neuron-, astrocyte-, or oligodendrocyte-specific markers, consistent with phenotypes of neural stem cells. These data suggest that Notch signaling promote the formation of cancer stem cell-like cells in human glioma.