Gestational diabetes mellitus combined with fulminant type 1 diabetes mellitus, four cases of double diabetes: A case report

BACKGROUND

Fulminant type 1 diabetes mellitus (FT1DM) that occurs during pregnancy or the perinatal period is known as pregnancy-related FT1DM (PF), always without history of abnormal glucose metabolism. Here, we present four patients who developed FT1DM during treatment but were first diagnosed with gestational diabetes mellitus (GDM).

CASE SUMMARY

The clinical data of four patients with GDM combined with FT1DM admitted to our hospital between July 2018 and April 2021 were collected, and the patients and their infants were followed up. All patients were diagnosed with GDM during the second trimester and were treated. The blood glucose level elevated suddenly during the third trimester and then were diagnosed with FT1DM. Two patients had an insulin allergy, and two had symptoms of upper respiratory tract infection before onset. One patient developed ketoacidosis, and three developed ketosis. Two patients had cesarean section deliveries, and two had vaginal deliveries. The growth and development of the infants were normal. C-peptide levels were lower than those at onset, suggesting progressive impairment of islet function. The frequencies of the DRB1 09:01, DQB1 03: 03, DQA1 03:02, DPA1 01:03, DPA1 02:02, DPB1 05:01, DRB4 01:03, G 01:01, and G 01:04 human leukocyte antigen (HLA)-G alleles were high in the present study.

CONCLUSION

In comparison with pregnancy-associated FT1DM (PF), patients with GDM combined with FT1DM had an older age of onset, higher body mass index, slower onset, fewer prodromal symptoms, and less acidosis. The pathogenesis may be due to various factors affecting the already fragile β-cells of GDM patients with genetically susceptible class II HLA genotypes. We speculate that GDM combined with FT1DM during pregnancy, referred to as "double diabetes," is a subtype of PF with its own unique characteristics that should be investigated further.

Linear porokeratosis of the foot with dermoscopic manifestations: A case report

BACKGROUND

Porokeratosis (PK) is a common autosomal dominant chronic progressive dyskeratosis with various clinical manifestations. Based on clinical manifestations, porokeratosis can be classified as porokeratosis of mibelli, disseminated superficial porokeratosis, disseminated superficial actinic porokeratosis, linear porokeratosis (LP), porokeratosis palmaris et plantaris disseminata, porokeratosis punctata, popular PK, hyperkeratosis PK, inflammatory PK, verrucous PK, and mixed types. We report a case of LP in a child and describe its dermoscopic findings.

CASE SUMMARY

Linear porokeratosis is a rare PK. The patient presented with unilateral keratinizing maculopapular rash of the foot in childhood. The patient underwent skin pathology and dermoscopy, and was treated with liquid nitrogen freezing and topical drugs.

CONCLUSION

From this case we take-away that LP is a rare disease, by the dermoscopic we can identify it.

[A case of arrhythmia caused by barium carbonate poisoning]

Barium carbonate poisoning is mostly caused by mistaken ingestion in clinical cases, and self-administration of poisoning is rare. In November 2020, Tianjin Occupational Disease Prevention Hospital admitted a patient with severe hypokalemia complicated with arrhythmia after taking poison. It is very important to take timely and effective potassium supplementation, symptomatic and detoxification treatment in the course of treatment. At the same time, closely observing the changes of vital signs and taking quick and accurate rescue measures in the event of malignant arrhythmia are the keys to ensuring the success of rescue. In this paper, the clinical data of the case were retrospectively analyzed, providing reference for the diagnosis and treatment of similar clinical cases.

Neuropathy and chloracne induced by 3,5,6-trichloropyridin-2-ol sodium: Report of three cases

BACKGROUND

Chloracne is a rare skin condition that is caused by systemic exposure to halogenated aromatic compounds. The main characteristic of chloracne is blackhead, and in severe cases, it can be accompanied by systemic symptoms. Sodium 3,5,6-trichloropyridin-2-ol (STCP) is a necessary precursor compound for the production of chlorpyrifos and triclopyr, which are extensively used as a pesticide and herbicide, respectively. STCP is also a chlorophenol that has been associated with chloracne. STCP poisoning could induce mild myelin sheath damage. We herein report three cases with chloracne due to exposure to STCP.

CASE SUMMARY

Three young men, aged 29, 33, and 26 years, respectively, in the same workplace had polymorphic skin lesions, characterized mainly by comedones and cysts, and one of them also had acne like lesions in the genital area. These clinical manifestations appeared when they were exposed to STCP for 3 d, 1 wk, and 2 wk, respectively. Among them, polyneuropathy and liver damage occurred. We performed dermoscopy and clinical and laboratory tests on these patients. Additionally, histopathology was used for further diagnosis in the serious patient. These patients were diagnosed with chloracne and separated from STCP. The patients were prescribed oral viaminate capsules, topical adapalene gel, and regular hematologic follow-up for aspartate transaminase and lipids. They are still under follow-up. There was no new lesions and the laboratory tests returned to normal in two patients. Pigmentation and shallow scars remained in the original areas of papules. However, in the most serious patient, new papules still appeared intermittently. All these remind us that the treatment of chloracne caused by STCP is difficult, and we should attach great importance to this new compound related with the neuropathy and chloracne.

CONCLUSION

STCP is becoming a new chemical product to induce chloracne, which should attract the attention of all medical professionals, especially dermatologists. Due to the lack of knowledge on the new chemical, the diagnosis of chloracne cannot be made in time. Chloracne still deserves our attention.

Depression of oncogenecity by dephosphorylating and degrading BCR-ABL

Aberrant phosphorylation and overexpression of BCR-ABL fusion protein are responsible for the main pathogenesis in chronic myeloid leukemia (CML). Phosphorylated BCR-ABL Y177 recruits GRB2 adaptor and triggers leukemic RAS-MAPK and PI3K-AKT signals. In this study, we engineered a SPOA system to dephosphorylate and degrade BCR-ABL by targeting BCR-ABL Y177. We tested its effect on BCR-ABL phosphorylation and expression, as well as cell proliferation and apoptosis in CML cells. We found that SPOA remarkably dephosphorylated BCR-ABL Y177, prevented GRB2 recruitment, and uncoupled RAS-MAPK and PI3K-AKT signals. Meanwhile, SPOA degraded BCR-ABL oncoprotein in ubiquitin-independent manner and depressed the signal transduction of STAT5 and CRKL by BCR-ABL. Furthermore, SPOA inhibited proliferation and induced apoptosis in CML cells and depressed the oncogenecity of K562 cells in mice. These results provide evidence that dephosphorylating and degrading oncogenic BCR-ABL offer an alternative CML therapy.

[Distribution and Accumulation of Cadmium in Paddy Soil and Rice Affected by Pollutant Sources Control and Improvement Measures]

The objective of this study was to determine the effect of five scenarios on the accumulation of Cd in the soil-rice system, including the return of straw to the field and the lack of the return, atmospheric deposition control, use of clean water for irrigation, and the use of lime. For the field experiments, three typical paddies were selected and divided into five plots (5 m×6 m) in Xiangtan, Zhuzhou, and Liling in the Hunan province from April to October 2016. The results showed that the application of lime can increase pH by 0.87, while the available Cd concentration in the soil was decreased by 33.7%. The accumulations of Cd in roots, stems, and brown rice were decreased by 47.9%, 46.7%, and 54.8%, respectively, with a decrease in the corresponding bioconcentration factors. Irrigating with clean water and liming tended to increase the soil pH by 0.44 and 0.49, respectively, while the available Cd concentration in the soil was decreased by 18.2% and 14.5%, respectively. The Cd concentrations in roots, stems, and brown rice were decreased by 32.6%, 24.2%, and 18.0%, and 17.6%, 11.3%, and 25.4% with decreased bioconcentration factors under both treatments (irrigating with clean water and liming). The available Cd concentration in the soil was increased by 6.1% and the Cd accumulation in the rice plants also increased with the return of straw to the soil. The bioconcentration factors of the rice plants were also increased when the paddy straw was returned to the fields. The results showed that the measures, such as the use of lime, atmospheric deposition control, use of clean water for irrigation, and lack of the return of straw to the paddy soil, should be helpful for the safe production of brown rice. The possible long-term risks associated with returning straw to the paddy field should be evaluated scientifically.

CAR-T therapy for leukemia: progress and challenges

Despite the rapid development of therapeutic strategies, leukemia remains a type of difficult-to-treat hematopoietic malignancy that necessitates introduction of more effective treatment options to improve life expectancy and quality of patients. Genetic engineering in adoptively transferred T cells to express antigen-specific chimeric antigen receptors (CARs) has proved highly powerful and efficacious in inducing sustained responses in patients with refractory malignancies, as exemplified by the success of CD19-targeting CAR-T treatment in patients with relapsed acute lymphoblastic leukemia. Recent strategies, including manipulating intracellular activating domains and transducing viral vectors, have resulted in better designed and optimized CAR-T cells. This is further facilitated by the rapid identification of an accumulating number of potential leukemic antigens that may serve as therapeutic targets for CAR-T cells. This review will provide a comprehensive background and scrutinize recent important breakthrough studies on anti-leukemia CAR-T cells, with focus on recently identified antigens for CAR-T therapy design and approaches to overcome critical challenges.

Potential role of Wnt/β-catenin signaling in blastic transformation of chronic myeloid leukemia: cross talk between β-catenin and BCR-ABL

Chronic myeloid leukemia (CML) results from malignant transformation of hematopoietic stem cells induced by the BCR-ABL oncogene. Transformation from chronic to blastic phase is the lethal step in CML. Leukemic stem cells (LSCs) are the basic reason for blastic transformation. It has been shown that Wnt/β-catenin signaling contributes to the self-renewal capacity and proliferation of LSCs in CML. However, the role of Wnt/β-catenin signaling in blastic transformation of CML is still obscure. Here, we explored the relationship between BCR-ABL and β-catenin signaling in vitro and in vivo. We found that BCR-ABL stimulated β-catenin via activation of PI3K/AKT signaling in blastic phase CML cells. Inhibition of the kinase activity of BCR-ABL, PI3K, or AKT decreased the level of β-catenin in both K562 cells and a CML mouse model and suppressed the transcription of downstream target genes (c-myc and cyclin D1). In addition, inhibition of the BCR-ABL/PI3K/AKT pathway delayed the disease progression in the CML mouse model. To further explore the role of β-catenin in the self-renewal and survival of CML LSCs, we established a secondary transplantation CML mouse model. Our data revealed that inhibition of the BCR-ABL/PI3K/AKT pathway reduced the tumor-initiating ability of K562 cells, decreased leukemia cell infiltration into peripheral blood and bone marrow, and prolonged the survival of mice. In conclusion, our data indicate a close relationship between β-catenin and BCR-ABL/PI3K/AKT in blastic phase CML. β-Catenin inhibition may be of therapeutic value by targeting LSCs in combination with a tyrosine kinase inhibitor, which may delay blastic transformation of CML.

Clinicopathological features of invasive lobular carcinoma of the breast: A nationwide multicenter study in China

OBJECTIVE

To analyze the clinicopathological features of invasive lobular carcinoma (ILC) and compare them with invasive ductal carcinoma (IDC), hoping to find the fact of ILC in China and assist the decision makers with proper individualized treatment.

MATERIALS AND METHODS

A nationwide multicenter retrospective study was performed. A total of 4211 primary breast cancer cases were randomly selected from 1999 to 2008 in seven regions of China. ILC cases were compared with IDC by clinicopathological features and molecular subtypes.

RESULTS

A total of 135 (3.2%) ILC and 3471 (82.4%) IDC cases were included for analysis. The age, tumor size, menopausal state, family history, nodal status, and stage of ILC were similar to that of IDC. ILC was more likely to be positive for estrogen receptor (65.5% vs. 57.7%) and progesterone receptor (64.7% vs. 58.5%), and less likely to overexpress human epidermal growth factor receptor-2 (17.3% vs. 23.6%). Even though, these differences are not significant, the proportion of luminal A type of ILC is significantly larger than that of IDC (54.8% vs. 42.7%; P < 0.05).

CONCLUSION

ILC has a larger proportion of luminal A type compared with IDC. Larger sample size study for better known of molecular subtypes of ILC is needed in future to individualize the treatment decision.

[Research Progress on Expression and Function of P2 Purinergic Receptor in Blood Cells]

Nucleotides have unambiguously emerged as a family of mediators of intercellular communication, which bind a class of plasma membrane receptors, P2 purinergic receptors, to trigger intercellular signaling. P2 receptors can be further divided into two structurally and functionally different sub-famlies, the P2X and P2Y receptors. Different blood cells express diverse spectrum of P2 receptors at different levels. Extracellular adenosine triphosphate (ATP) exerts different effects on blood cells, regulating cell proliferation, differentiation, migration, chemotaxis, release of cytokines or lysosomal constituents, and generation of reactive oxygen or nitrogen species. The relationship between abnormal P2 receptors and human diseases attracts more and more attention. This review briefly discusses the expression and function of P2 receptors in hematopoietic system.

[Indomethacin Significantly Enhances Inhibitory Effect of Imatinib on Proliferation of KCL22 and K562/G01 Cells]

OBJECTIVE

To investigate the inhibitory effect of indomethacin combined with imatinib on proliferation of KCL22 and K562/G01 cells, and to elucidate the molecular mechanism of antiproliferative effect by Wnt/β-Catenin signaling way.

METHODS

Indomethacin was used in KCL22 and K562/G01 cells. The cell growth was detected by MTT assay to explore the optimal concentration and time. The effect of drugs on proliferation capacity was assessed by MTT assay and colony-forming assay. Flow cytometry was used to identify the cell cycle and apoptosis changes. The protein expression of pβ-catenin (S33/37/T41), pGSK-3β (Ser9) and C-MYC were analyzed by Western blot.

RESULTS

The optimal concentration and time of indomethacin on KCL22 and K562/G01 were 80 µmol/L for 48 h. The inhibitory effect of 80 µmol/L indomethacin combined 2 µmol/L imatinib on cell proliferation was significantly better than a single drug treatment. Flow cytometry results showed that cell cycle was arrested in the G0/G1 phase in both combined treatment groups. The number of apoptosis cells in combined treatment groups was significantly higher than that in single drug treatment groups. Compared with the control group or single drug treatment groups, the protein level of pβ-catenin, β-catenin, pGSK-3β (Ser9) and C-MYC decreased significantly.

CONCLUSION

Indomethacin significantly enhances inhibitory effect of imatinib on proliferation of KCL22 and K562/G01 cells and regulate cell proliferation through Wnt/β-Catenin signaling way.

[Effect of Recombinant Adenovirus AdE-SH2-Caspase 8 on the Apoptosis of Imatinib-resistant K562/G01 Cell Line]

OBJECTIVE

To investigate the effect of SH2-Caspase 8 fusion protein expressed by recombinant adenovirus AdE-SH2-Caspase8-HA-GFP (SC) on the apoptosis of K562/G01 cell line, which is a BCR/ABL positive chronic myeloid leukemia cell line and resistant to imatinib.

METHODS

The K562/G01 cell line was infected with AdE-SH2-Caspase 8-HA-GFP adenovirus (SC), then the cells were divided into 3 groups: AdE-SH2m-Caspase 8-HA-GFP (SmC) group, AdE-GFP (CMV) group and PBS group as control. The infection efficiency was observed under fluorescent microscopy and by flow cytometry. The expression of fusion protein SH2-Caspase 8-HA was measured by Western blot. The morphology of the cells detected by Wright's staining. The apoptosis of the cells were detected by flow cytometry and DNA ladder. The expression of Caspase 3 and PARP were detected by Western blot.

RESULT

The infection efficiency of SC on K562/G01 cells was high which was confirmed by fluorescent microscopy and FCM. SH2-Caspase 8-HA fusion protein were expressed correctly in K562/G01 cells. After treatment with SC the apoptosis of K562/G01 cells could be observed by microscopy. The result of FCM showed that early apoptosis of K562/G01 cells increased significantly as compared with control groups (P < 0.05). DNA ladder showed that the classic DNA ladders appeared in K562/G01 cells after treatment with SC. The wester blot detection showed that the expression level of apoptosis-related protein Caspase 3 and PARP increased.

CONCLUSION

The recombinant adenovirus SC expressing SH2-Caspase 8 fusion protein can induces the apoptosis of K562/G01 cells.

PMT1 deficiency enhances basal UPR activity and extends replicative lifespan of Saccharomyces cerevisiae

Pmt1p is an important member of the protein O-mannosyltransferase (PMT) family of enzymes, which participates in the endoplasmic reticulum (ER) unfolded protein response (UPR), an important pathway for alleviating ER stress. ER stress and the UPR have been implicated in aging and age-related diseases in several organisms; however, a possible role for PMT1 in determining lifespan has not been previously described. In this study, we report that deletion of PMT1 increases replicative lifespan (RLS) in the budding yeast Saccharomyces cerevisiae, while overexpression of PMT1 (PMT1-OX) reduces RLS. Relative to wild-type and PMT1-OX strains, the pmt1Δ strain had enhanced HAC1 mRNA splicing and elevated expression levels of UPR target genes. Furthermore, the increased RLS of the pmt1Δ strain could be completely abolished by deletion of either IRE1 or HAC1, two upstream modulators of the UPR. The double deletion strains pmt1Δhac1Δ and pmt1Δire1Δ also displayed generally reduced transcription of UPR target genes. Collectively, our results suggest that PMT1 deficiency enhances basal activity of the ER UPR and extends the RLS of yeast mother cells through a mechanism that requires both IRE1 and HAC1.

Organ-specific microenvironment modifies diverse functional and phenotypic characteristics of leukemia-associated macrophages in mouse T cell acute lymphoblastic leukemia

Tumor-associated macrophages are widely studied in solid tumors. The distribution of macrophages in lymph node samples was found to be associated with the prognosis of lymphoma patients. However, the role of macrophages in leukemia and their functional and phenotypic characteristics in hematopoietic malignancies have not been defined. In this study, we examined the distribution and functional and phenotypic characteristics of macrophages in a Notch1-induced mouse model of T cell acute lymphoblastic leukemia (T-ALL). The distribution of macrophages in bone marrow (BM) and spleen, which are proposed as BM and spleen leukemia-associated macrophages (LAMs), were different during the development of leukemia. LAMs stimulated the proliferation of T-ALL cells and had higher migration activity. RNA-sequencing analysis revealed that gene expression profiles of BM and spleen LAMs showed considerable differences. RT-PCR analysis showed that LAMs expressed both M1- and M2-associated phenotypic genes, but they expressed much lower levels of TGF-β1, VEGF-A, and CSF-1 than did tumor-associated macrophages from B16 melanoma. Furthermore, spleen LAMs more potently stimulated the proliferation of T-ALL cells compared with BM LAMs. Moreover, LAMs could be subdivided into M1-like (CD206(-)) and M2-like (CD206(+)) groups. Both CD206(+) and CD206(-) LAMs stimulated the proliferation of T-ALL cells, although CD206(+) LAMs expressed higher levels of most M1- and M2-associated genes. These results suggested the functional and phenotypic characteristics of LAMs, which were modified by organ specific microenvironments. Our results broaden our knowledge about macrophages in malignant microenvironments from solid tumors to leukemia.

Induction of apoptosis by directing oncogenic Bcr-Abl into the nucleus

The chimeric Bcr-Abl oncoprotein, which causes chronic myeloid leukemia, mainly localizes in the cytoplasm, and loses its ability to transform cells after moving into the nucleus. Here we report a new strategy to convert Bcr-Abl to be an apoptotic inducer by altering its subcellular localization. We show that a rapalog nuclear transport system (RNTS) containing six nuclear localization signals directs Bcr-Abl into the nucleus and that nuclear entrapped Bcr-Abl induces apoptosis and inhibits proliferation of CML cells by activating p73 and shutting down cytoplasmic oncogenic signals mediated by Bcr-Abl. Coupling cytoplasmic depletion with nuclear entrapment of Bcr-Abl synergistically enhances the inhibitory effect of nuclear Bcr-Abl on its oncogenicity in mice. These results provide evidence that direction of cytoplasmic Bcr-Abl to the nucleus offers an alternative CML therapy.

[Expression of P2X family receptors in peritoneal macrophages of mouse with acute T lymphoblastic leukemia]

This study was aimed at exploring the expression pattern of P2X family receptors (P2XR) in peritoneal macrophages and their relationship with the activation states of macrophages in Notch1-induced mouse T-ALL model. After establishment of the leukemia model, F4/80(+) peritoneal macrophages, F4/80(+)CD206(+) M2-like and F4/80(+)CD206(-) M1-like peritoneal macrophages were sorted by flow cytometry based on F4/80 and CD206 surface markers. The expression of P2XR in each cell population was detected by real time RT-PCR. The results showed that macrophages,M1-like and M2-like macrophages moderately expressed P2XR except for P2X5R. The expression of P2XR varied with the development of leukemia. The expression of P2X1R and P2X7R in peritoneal macrophages increased steadily; the expression of P2X2R and P2X3R decreased at late stage of leukemia;the expression of P2X4R slightly decreased at intermediate stage;the expression of P2X6R kept unchanged. At intermediate stage of leukemia, the expression of P2XR in M1-like and M2-like peritoneal macrophages varied. M1-like macrophages expressed higher level of P2X1R than M2-like macrophages, whereas M2-like macrophages expressed higher level of P2X7R than M1-like macrophages, which suggested that the expression of P2XR were related to the activation states. It is concluded that the expression of P2XR in peritoneal macrophages from leukemia mice is related to the progression of leukemia and the activation states of macrophages, which lay a foundation for further studying the role of macrophages in the development of leukemia.

Clinical presentation of a patient with congenital cutis laxa and abnormal thyroid hormone levels

We describe a case of generalized cutis laxa (CL) in a 7-year-old female child. At 2 months of age, she was found to have a hoarse voice, and at 3 years, she was much smaller than her peers. Her aging face and short stature caught our attention, and the treatment of the patient was accepted by our hospital. She underwent a thorough examination. X-ray of the wrist bone showed a markedly delayed bone age, and thyroid function tests revealed significantly elevated free triiodothyronine 3 and free thyroxine 4 levels, but thyrotropin was within the normal range. Thyroid dysfunction and CL can be associated with lagged growth and development. Whether her abnormal development was due to thyroid dysfunction or CL could not be ascertained. CL is possibly more complex than it has been supposed so far, and is therefore worth to be further studied.

Cell-penetrating fusion peptides OD1 and OD2 interact with Bcr-Abl and influence the growth and apoptosis of K562 cells

The Bcr-Abl oncoprotein is the cause of chronic myelogenous leukemia (CML). Crystal structure analysis suggests that Bcr30-63 is the core of the Bcr-Abl oligomerization interface for aberrant kinase activity; however, the precise role of other residues of Bcr1-72 excluding Bcr30-63 have not been evaluated. In this study, Bcr30-63 was named OD2 and other residues of Bcr1-72 were named OD1. Cytoplasmic transduction peptide (CTP) was used to carry molecules into cytoplasm. CTP-OD1 and CTP-OD2 fusion peptides were expressed from a cold-inducible expression system. Our results demonstrated that both fusion peptides could localize into the cytoplasm, specifically interact with the Bcr-Abl protein and further inhibit growth, induce apoptosis, and decrease the phosphorylation of Bcr-Abl in K562 cell lines. However, the viability of THP-1, a Bcr-Abl negative cell line, was unaffected. These results suggested that CTP-OD1 and CTP-OD2 may be an attractive therapeutic option to inhibit the activation of Bcr-Abl kinase in CML.

[Dual over-expression of P2X7 receptor and intracellular domain of Notch1 in leukemia cells]

This study aimed to construct the dual expression vectors of wide type or N187D mutant P2X7 receptor and intracellular domain of Notch1 (ICN1) linked by 2A peptide to coexpress them in leukemia cells so as to lay a foundation for further investigating the role of P2X7 in development of leukemia. Overlap PCR was used to construct the dual expression vectors encoding wide type or N187D mutant type P2X7 receptor and ICN1 linked by the self-cleaving 2A sequence. The results showed that stable expressing cell lines were obtained by retroviral infection followed by cell sorting after DNA sequence analysis. RT-PCR, Western blot, intracellular free calcium concentration analysis were used to verify the functionally successful construction of K562 cell line expressing P2X7 receptor alone or with ICN1. DNA sequence analysis revealed that all construction were right. The infection efficiency of packaged constructed virus ranged from 40% to 70% for K562 cells. Stable infected cell line was obtained by cell sorting. RT-PCR analysis revealed that P2X7 receptor and/or ICN1 could be detected at high level in their stable infected cell lines, respectively. Western blot analysis also showed that P2X7 receptor was highly expressed in cell line infected by virus with P2X7 receptor. Sustained increase in intracellular free calcium concentration ([Ca(2+)]i) could be observed in K562 cells overexpressing either type of P2X7 receptor upon stimulation with BzATP. It is concluded that the wide type or N187D mutant P2X7 receptor and ICN1 are simultaneously and functionally over-express in leukemia cells, which lay a foundation for further studying the role of P2X7 receptor in the development of leukemia.

Targeting BCR tyrosine177 site with novel SH2-DED causes selective leukemia cell death in vitro and in vivo

Emergence of resistance to imatinib mesylate complicates the treatment of chronic myeloid leukemia (CML). Second-generation tyrosine kinase inhibitors are capable to overcome resistance mediated by most mutations except T315I. As this mutation is causative for 20% of clinically observed resistances, the need for novel treatment strategies becomes obvious and urgent. The autophosphorylated BCR/ABL Tyr177 recruits Grb2 via its SH2 domain, which is required for efficient induction of the myeloproliferative disease by BCR/ABL. The death effector domain (DED) is the critical factor for activation of caspase-8 induced apoptosis signal. We thus speculated that transduction of an exogenous SH2-DED (SD) fragment into the CML cells may inhibit the binding of BCR/ABL Tyr177 and Grb2, activate caspase-8 induced apoptosis and serve as a novel CML treatment strategy. The infection of the recombinant adenovirus Ad5/F35-SD was verified to show both cell proliferation-inhibitory and apoptosis-inducing effect. Further exploration into the underlying mechanisms revealed that Ad5/F35-SD exerted its function by binding to the phospho-BCR/ABL Tyr177 site, reducing Ras, MAPK and AKT kinase activities, and activating caspase-8 induced apoptosis signal by DED protein binding to DED domain of precursor caspase-8. Moreover, high anti-proliferative activity of Ad5/F35-SD was observed in nude mice and its leukemia-protective effect was evident in chronic myeloid leukemia model mice injected with BCR/ABL(+) BaF3 cells. In conclusion, Ad5/F35-SD exhibits anti-proliferative and pro-apoptotic activity on BCR/ABL positive leukemia cells in vitro and in vivo through disruption of Grb2 SH2-phospho-BCR/ABL Tyr177 complex formation and induction of caspase-8 activation.

Enhancement of specific cellular immune response induced by glycosyl-phosphatidylinositol-anchored BCR/ABL and mIL-12

bcr/abl fusion gene is thought to be a promising target for chronic myelogenous leukemia (CML) patients to enhance immune response after attaining complete remission. In this study, we sought to enhance cellular immunity by co-expression of BCR/ABL and murine IL-12 gene on the tumor cell surface as a glycosyl-phosphatidylinositol (GPI)-form. The successfully constructed plasmid pBudCE4.1-BCR/ABL-GPI-mIL12 resulted in high levels of splenocyte proliferative responses, significant levels of IL-2 and IFNγ, and strong cytotoxic T-lymphocyte (CTL) responses in vitro. In a murine transplant model, the vaccinated mice showed decreased infiltration of leukemia cells and reduced expression of BCR/ABL transcripts and protein in bone marrow cells. Results of the present study indicated that this novel immunization strategy is useful in enhancing immune protection in mice, which would provide new insights into the development of effective vaccines for treating CML.

Theoretical investigation for the EPR g-factors of the mixed ground state in NaCl: Ag2+ crystals

In this paper, it is considered that the local structure of the (AgCl6)4- cluster for the NaCl: Ag2+ crystal is of the axially elongational D4h symmetry which possesses the weaker rhombic distortion at <001> lattice site. The mechanism for an admixture of the 2A1g into the ground state 2B1g is taken into account. The electron paramagnetic resonance (EPR) g factors of NaCl: Ag2+ are studied by using the double spin-orbit coupling model and an approximation of a semiempirical molecular orbit. The EPR g factors for the NaCl: Ag2+ crystals are reasonably explained as well as the good agreement between the calculated values and the experimental data is obtained.

Selective leukemia cell death by activation of the double-stranded RNA-dependent protein kinase PKR

Deregulated activity of the BCR-ABL tyrosine kinase encoded by the Bcr-Abl oncogene represents an important therapeutic target for all the chronic myelogenous leukemia (CML) phases. In this study, we sought to identify targeted PKR activation by Bcr-Abl AS RNA, an anti-sense RNA complementary to the unique mRNA fragments flanking the fusion point of Bcr-Abl, which can be used as an effective anti-leukemia strategy in K562 cells. Moreover, we observed expression of Bcr-Abl AS RNA in K562 cells which resulted in selective apoptosis induction through specific activation of PKR, leading to phosphorylation of eIF2α, global inhibition of protein synthesis, caspase-8 activation and BAX up-regulation. The targeted PKR activation and induced apoptosis were reversed by the PKR inhibitor 2-aminopurine. Taken together, our results indicate that targeted PKR activation led to selective apoptosis induction in K562 cells, which correlated with caspase-8 activity and enhanced expression of BAX.

Growth of chronic myeloid leukemia cells is inhibited by infection with Ad-SH2-HA adenovirus that disrupts Grb2-Bcr-Abl complexes

The persistence of Bcr-Abl-positive cells in patients on imatinib therapy indicates that inhibition of the Bcr-Abl kinase activity alone might not be sufficient to eradicate the leukemia cells. Many downstream effectors of Bcr-Abl have been described, including activation of both the Grb2-SoS-Ras-MAPK and Grb2-Gab2-PI3K-Akt pathways. The Bcr-Abl-Grb2 interaction, which is mediated by the direct interaction of the Grb2 SH2 domain with the phospho-Bcr-Abl Y177, is required for activation of these signaling pathways. Therefore, disrupting their interaction represents a potential therapeutic strategy for inhibiting the oncogenic downstream signals of Bcr-Abl. Adenovirus Ad-SH2-HA expressing the Grb2 SH2 domain was constructed and applied in this study. As expected, Ad-SH2-HA efficiently infected CML cells and functioned by binding to the phospho-Bcr-Abl Y177 site, competitively disrupting the Grb2 SH2-phospho-Bcr-Abl Y177 complex. They induced potent anti-proliferation and apoptosis-inducing effects in CML cell lines. Moreover, the Ras, MAPK and Akt activities were significantly reduced in the Ad-SH2-HA treated cells. These were not observed with the point-mutated control adenovirus Ad-Sm-HA with abolished phospho-Bcr-Abl Y177 binding sites. These data indicate that, in addition to the direct targeting of Bcr-Abl, selective inhibition of its downstream signaling pathways may be a therapeutic option for CML, and the Ad-SH2-HA-mediated killing strategy could be explored as a promising anti-leukemia agent in CML.

Cloning, expression, purification, distribution and kinetics characterization of the bacterial beta-galactosidase fused to the cytoplasmic transduction peptide in vitro and in vivo

Cytoplasmic transduction peptide (CTP) offers exciting therapeutic opportunities for the treatment of many diseases caused by cytoplasmic functional molecules. It can transduce large, biologically active proteins into the cytoplasmic compartment of several mammalian cells. However, other intriguing features of CTP, including its activity in vitro, and distribution and tissue infiltration abilities in vivo, remain to be explored. The present study was initiated to (1) further confirm the cytoplasmic localization preference and the enzymatic activity of the transduced CTP-beta-gal in vitro and (2) examine the kinetics and tissue distribution of the CTP-beta-gal fusion protein in mice. A CTP-beta-gal fusion protein was expressed in Escherichia coli and either transduced into BaF3-BCR/ABL cells or administered intravenously into female Balb/C mice at a dose of 100 microg per mouse. Its localization in BaF3-BCR/ABL cells was evaluated by immunocytochemistry and in situ X-gal staining, and its distribution in various tissues was analyzed both by in situ X-gal staining and quantitative enzymatic activity assay. beta-Galactosidase enzyme activity was observed in BaF3-BCR/ABL cells and in all tissues tested, with peak activity occurring at 15 min in most tissues and at 24h in brain. These data will not only allow rational selection of delivery schedules for therapeutic CTP, but will also aid the use of CTP fusion protein transduction in the development of protein therapeutics targeting the cytoplasmic compartment both in vitro and in vivo.

Inhibitory effect of wild-type p53 gene on excessive replication of centrosomes in leukemia cell line K562

BACKGROUND AND OBJECTIVE

Mutation and deletion of the p53 gene in tumor cells is one of the major reasons for aneuploid development and genomic instability. Abnormal centrosomes exist in chronic myelogenous leukemia patients at different stages; furthermore, the degree of abnormality is associated with the clinical stage and more severe in the blast crisis stage. This study was to establish the leukemia cell line K562 with the exogenous wild-type p53 (wt-p53) gene, and to explore the effect of the p53 gene on centrosomes in K562 cells.

METHODS

The recombinant adenoviruses carrying the wt-p53 gene (Ad5wtp53), the mutant p53 gene (Ad5mtp53) and the green fluorescent protein gene (Ad5GFP) were amplified respectively in HEK293 cells, and co-infected with cation polybrene into K562 cells respectively; uninfected K562 cells were used as blank control. The infection efficiency was analyzed by flow cytometry. P53 expression was detected by Western blot. Centrosomes were counted under the laser confocal microscope after indirect immunofluorescence staining. The expression of Gadd45a (growth arrest and DNA damage), BubR1 (Bub 1 related) and Aurora A was detected by western blot.

RESULTS

K562 cell line with exogenous wt-p53 gene was established. The infection efficiencies of three groups were over 60%, and P53 sustained expression for 72 h. The percentage of cells with amplified centrosomes (more than 2/cell) in Ad5wtp53 group was decreased to (0.38 +/- 0.02)%, lower than that of blank control group (p < 0.05). Meanwhile, the protein levels of Gadd45a and BubR1 in Ad5wtp53 group were upregulated by 93% and 88% of blank control (p < 0.05), respectively, and the protein level of Aurora A was downregulated by 56% of blank control (p < 0.05).

CONCLUSIONS

P53 protein is sustained to express in K562 cells after being infected by Ad5wtp53. wt-p53 can suppress excessive replication of centrosomes that may contribute to the upregulation of Gadd45a and BubR1 protein expression as well as the downregulation of Aurora A protein expression.

[Targeted blockage of RNA binding protein E2 by decoy RNA induces the granulocytic differentiation of K562 cells]

OBJECTIVE

To use a decoy RNA targeted blockage of the RNA binding protein E2 (hnRNP E2) resulting in the CCAAT/enhancer-binding protein alpha (C/EBP alpha) gene's abnormal translation and investigate its effect on the granulocytic differentiation of K562 cells and the probable molecular mechanism.

METHODS

The hnRNP E2 decoy RNA expression plasmid was constructed and transfected into K562 cells with cationic liposome, and stable expression cells were obtained by G418 selection. The changes of C/EBP alpha and granulocyte colony-stimulating factor receptor (G-CSFR) gene expression were detected by RT-PCR and Western blot. The morphologic changes were observed after Wright-Giemsa staining. The expression of granulocytic differentiation antigens CD13 and CD15 was studied by immunocytochemistry.

RESULTS

The stably expressed pG cells were obtained. Its C/EBP alpha mRNA level remained unchanged, while 42kD-C/EBP alpha protein expression was increased by (49.7 +/- 5.5)% (P < 0.05); and G-CSFR mRNA was increased by (42.1 +/- 3.6)% (P < .05), and its protein was increased by (37.4 +/- 6.2)% (P < 0.05) compared to that in the K562 control cells. The characteristics of polymorphonuclear neutrophils appeared in pG cells and CD13 and CD15 positive cell ratios were (18.7 +/- 2.5)% and (26.3 +/- 2.9)% respectively.

CONCLUSIONS

HnRNP E2 decoy RNA can induce granulocytic differentiation of K562 cells, and G-CSF promotes this effect. The mechanisms may be that decoy RNA specifically blocks hnRNP E2, hence regulates the translation of C/ EBP alpha mRNA, restores the expression of 42kD-C/EBP alpha, and then up-regulates the expression of G-CSFR gene.

[Effect of targeted activation of protein kinase PKR on proliferation of leukemia cell line K562 and its mechanism]

BACKGROUND & OBJECTIVE

The bcr-abl fusion gene induced by reciprocal translocation of t(9; 22)(q34; q11) plays an important role in pathogenesis of chronic myeloid leukemia (CML). Using the strategy of activating double-stranded RNA (dsRNA)-dependent protein kinase (PKR) by the dsRNA formed between the CML-specific bcr/abl fusion gene mRNA and the exogenous recombinant antisense RNA, this study was to investigate the effect of the activated PKR on the proliferation of leukemia cell line K562, and explore its possible mechanisms.

METHODS

dsRNA analogue polyriboinosinic polyribocytidylic acid (PolyIC), retroviral vector containing 40 bp of bcr/abl fusion gene sequence (RV-40AS), RV-40AS and 2-aminopurine (2-AP), and retroviral vector containing green fluorescent protein sequence (RV-GFP) were transfected or infected into K562 cells respectively; ECV304 cells were used as control. Cell proliferation was determined by cell counting, MTT assay, and semisolid clone formation experiment. Cell cycle was analyzed by flow cytometry (FCM). The expression of PKR, phosphated PKR (p-PKR), eukaryotic initiation factor-2alpha (eIF2alpha), and phosphated eIF2alpha (p-eIF2alpha) was detected by Western blot. Total protein synthesis was studied by 3H-leucine incorporation.

RESULTS

polyIC inhibited the proliferation of K562 cells and ECV304 cells unspecifically, while RV-40AS only inhibited the proliferation of K562 cells specifically. 2-AP blocked the inhibitory effect of RV-40AS on the proliferation of K562 cells. The S phase proportion was significantly lower in polyIC-and RV-40AS-treated K562 cells than in untreated cells [(37.26+/-2.35)% and (31.48+/-3.65)% vs. (58.53+/-5.42)%, P<0.05], while the G0/G1 phase proportion was significantly higher in polyIC-and RV-40AS-treated cells than in untreated cells [(50.97+/-2.18)% and (57.47+/-3.61)% vs. (36.44+/-4.20)%, P<0.05]. The expression of p-PKR and p-eIF2alpha in polyIC-and RV-40AS-treated K562 cells and polyIC-treated ECV304 cells was obviously up-regulated. The total protein synthesis level was significantly lower in RV-40AS-treated K562 cells than in untreated K562 cells [(3.5+/-1.9) cpm/ng vs. (26.8+/-2.6) cpm/ng, P<0.05].

CONCLUSION

Targeted activation of PKR could inhibit the proliferation of K562 cells through inhibiting protein synthesis, and arresting progression of cell cycle.

[Effect and possible mechanism of HnRNP E2 decoy RNA on proliferation of K562 leukemia cells]

BACKGROUND & OBJECTIVE

The abnormal expression of poly(rC)-binding protein E2 (hnRNP E2) induced by BCR/ABL plays an important role in blast crisis of chronic myeloid leukemia (CML). The present study was to investigate the effect of hnRNP E2 decoy RNA on the cell proliferation in K562 leukemia cells, and further elucidate the possible underlying mechanisms.

METHODS

Decoy hnRNP E2 plasmid was constructed and transfected into K562 cells using cationic liposome. Stably transfected cells were selected with G418. The cell proliferation rate was determined by cell growth curve using trypan blue staining, and the cell cycle was analyzed by flow cytometry. The changes of CCAAT/enhancer-binding protein alpha (C/EBP alpha) and c-Myc gene expression were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot.

RESULTS

The proliferation rate of stably transfected K562 cells was inhibited by (62.73+/-12.92)%. The cell cycle was arrested at S phase [stably transfected K562 cell group: (55.59+/-4.67)%, control group: (44.70+/-4.21)%, P<0.05]; C/EBPalpha mRNA level remained unchanged. However the 42 ku-C/EBPalpha protein expression was elevated by (49.72+/-5.58)%; c-Myc mRNA and protein expression was inhibited by (58.27+/-7.23)% and (57.26+/-6.52)%, respectively.

CONCLUSION

HnRNP E2 decoy RNA could inhibit the proliferation of K562 cells, and this may be caused by the blockage of the binding between hnRNP E2 and C/EBPalpha mRNA and subsequent elevation of 42 ku-C/EBPalpha by decoy RNA.

[Regulatory effect of STAT5 decoy oligonucleotides on trans-activation of bcl-x gene promoter in K562 cells]

BACKGROUND & OBJECTIVE

Constitutive activation of signal transducers and activators of transcription 5 (STAT5) plays an important role in malignant transformation of chronic myeloid leukemia (CML) cells. This study was to explore regulatory effect of STAT5 decoy oligonucleotides (ODNs) on trans-activation of its downstream target bcl-x gene in K562 cells.

METHODS

STAT5 decoy ODNs, mismatched ODNs (M-ODNs), and FAM-decoy ODNs were designed and synthesized. FAM-decoy ODNs were used as control, and transfected into K562 cells by cationic liposomes, analyzed by flow cytometry (FCM) and fluorescent inversive microscopy. The bcl-x promoter fragment acquired by polymerase chain reaction (PCR) was inserted into pGL3-basic to construct luciferase report plasmid pGL3b-bclxp, which was co-transfected with decoy ODNs or M-ODNs into K562 cells. The activity of luciferase was detected. After transfection of decoy ODNs, and M-ODNs, expression of bcl-xL mRNA in K562 cells was detected by reverse transcription-PCR (RT-PCR),cell apoptosis was detected by FCM.

RESULTS

FAM-decoy ODNs were incorporated into K562 cells in a dose-dependent manner. The incorporation efficiency reached 99.1% at the concentration of 4 micromol/L 24 h after transfection, and green fluorescence could be observed in cells under fluorescent inversive microscope. The luciferase activity was significantly lower in STAT5 decoy ODNs group than in control group [(181.48+/-204.46) RLU/microg protein vs. (675.26+/-62.91) RLU/mug protein, P < 0.05], but that of M-ODNs group [(632.07+/-98.95) RLU/microg protein] has no significant difference with that of control group (P > 0.05). mRNA level of bcl-xL was decreased by STAT5 decoy ODNs, but not by M-ODNs. Moreover, Sub G1 peak was detected in STAT5 decoy ODNs group by FCM.

CONCLUSION

Transfection of STAT5 decoy ODNs can down-regulate the trans-activation of bcl-x in K562 cells.

[Effect of Skp2 antisense oligodeoxynucleotide on growth and proliferation of K562 cells]

BACKGROUND & OBJECTIVE

The ubiquitin-proteosome pathway is important for selective degradation of short-lived protein in eukaryotic cells. In this pathway Skp2 (S-phase kinase-associated protein 2) plays a critical role in degrading cyclin-dependent kinase inhibitor p27. It is verified that Skp2 is an oncoprotein that promotes cell cycle progression in solid tumor, but its role in leukemia cells remains unclear. This study was designed to investigate the effect of Skp2 antisense oligodeoxynucleotides(ASODN) on the growth and proliferation of leukemic K562 cells and its probable mechanism.

METHODS

K562 cells were cocultured with Skp2 ASODN. The growth and proliferation of K562 cells were observed with light microscopy and MTT assay. The cell cycle was analyzed using flow cytometry. The expression levels of mRNA and protein were determined using reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry, respectively.

RESULTS

After treatment with Skp2 ASODN, the growth and proliferation of K562 cells were inhibited and the cell cycle was arrested at G(0)/G(1) phase(Skp2 ASODN group 39.7+/-9.1% vs. control group 31.5+/-7.3%,P< 0.05). Both Skp2 mRNA and its protein levels were down-regulated. Although p27 mRNA level remained unchanged, its protein level was up-regulated.

CONCLUSION

Skp2 ASODN can inhibit the growth and proliferation of K562 cells, which is mediated by interfering with ubiquitin-proteosome system and regulating of cell cycle progression.

[The effect of ginseng stem, leaf and rhizoma saponins on the formation of lipid peroxides in rats of various ages]

The effect of saponins isolated from the stem, leaf and rhizoma of panax ginseng on the formation of lipid peroxides in aged (30, 24 and 20 months) and middle-aged (14 months) wistar rats was studied with both in vivo and in vitro methods. The results showed: The formation of lipid peroxides increased with age in rats and mice: the two saponins of ginseng stem, leaf and rhizoma can obviously inhibit the lipid peroxidation in the serum (plasma) and liver homogenate of aged and middle-aged rats (p less than 0.05 and less than 0.001). The same effect was also shown in the aged LACA mouse (18 months) experiment.