A rare case report of reversible glucose counterregulation in an insulinoma patient with type 2 diabetes.

CONTEXT: Insulinoma is a neuroendocrine tumor derived from pancreatic ß -cells whose clinical manifestation is recurrent hypoglycemia. Insulinoma in a patient with preexisting diabetes is extraordinarily rare, and the unmasking of type 2 diabetes (T2DM) after insulinoma surgery is even rarer. CASE REPORT: This article reports a 49-year-old male patient with insulinoma that masked the diagnosis of T2DM. The patient was admitted to the hospital with symptoms of hypoglycemia, such as repeated sweating, palpitations, and asthenia for over 4 years. The patient was diagnosed with insulinoma after completing relevant examinations. The emergence of hyperglycemia after the removal of insulinoma is attributable to the coexistence of T2DM. Surprisingly, a reversible decrease in cortisol levels was observed during the diagnostic process. We searched the previously published reports of this type of case from PubMed to determine why type 2 diabetes was covered by insulinoma and why glucocorticoids decreased. CONCLUSIONS: The diagnosis of T2DM in the patient after surgery may be related to increased food intake and insulin resistance induced by hyperinsulinemia caused by long-term hypoglycemia. The reversible decrease in cortisol levels, not adrenocortical insufficiency during the diagnostic process, may be caused by a transient abnormality in glucose counterregulation.

8-CPT-cAMP/all-trans retinoic acid targets t(11;17) acute promyelocytic leukemia through enhanced cell differentiation and PLZF/RARα degradation.

The refractoriness of acute promyelocytic leukemia (APL) with t(11;17)(q23;q21) to all-trans retinoic acid (ATRA)-based therapy concerns clinicians and intrigues basic researchers. By using a murine leukemic model carrying both promyelocytic leukemia zinc finger/retinoic acid receptor-α (PLZF/RARα) and RARα/PLZF fusion genes, we discovered that 8-chlorophenylthio adenosine-3', 5'-cyclic monophosphate (8-CPT-cAMP) enhances cellular differentiation and improves gene trans-activation by ATRA in leukemic blasts. Mechanistically, in combination with ATRA, 8-CPT-cAMP activates PKA, causing phosphorylation of PLZF/RARα at Ser765 and resulting in increased dissociation of the silencing mediator for retinoic acid and thyroid hormone receptors/nuclear receptor corepressor from PLZF/RARα. This process results in changes of local chromatin and transcriptional reactivation of the retinoic acid pathway in leukemic cells. Meanwhile, 8-CPT-cAMP also potentiated ATRA-induced degradation of PLZF/RARα through its Ser765 phosphorylation. In vivo treatment of the t(11;17) APL mouse model demonstrated that 8-CPT-cAMP could significantly improve the therapeutic effect of ATRA by targeting a leukemia-initiating cell activity. This combined therapy, which induces enhanced differentiation and oncoprotein degradation, may benefit t(11;17) APL patients.

The prognostic value of immunohistochemical subtyping in Chinese patients with de novo diffuse large B-cell lymphoma undergoing CHOP or R-CHOP treatment.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with recognised variability in molecular aetiology and clinical outcome. Though the use of agents such as rituximab significantly improves outcome, intrinsic genetic and morphological factors greatly affect the response to treatment. The objective of this study was to evaluate the prognostic value of immunohistochemical subtyping and the International Prognostic Index (IPI) for predicting treatment outcome in Chinese DLBCL patients. We followed 108 cases of DLBCL and performed prognostic analyses based on molecular subtyping of the disease through immunostaining of tissue samples. The use of rituximab conferred a clinical benefit to DLBCL patients regardless of disease subtype. Importantly, this treatment regimen also improved outcomes in patients with the non-germinal centre B-cell-like (GCB) DLBCL subtype, frequently associated with poorer prognosis. Our results suggest that IPI was the best tool for the prediction of treatment outcome in our patient cohort, regardless of treatment regimen. Furthermore, the use of rituximab alongside classical chemotherapy regimens can improve the outcomes for DLBCL patients who exhibit both GCB and non-GCB subtypes of the disease.

[Clinical study on fludarabine combined with cytarabine regimen in the treatment of patients with refractory and relapsed acute myeloid leukemia].

The aim of study was to evaluate the clinical efficacy and toxicity of fludarabine combined with cytarabine (FA) regimen in the treatment of patients with refractory and/or relapsed acute myeloid leukemia (AML). Nineteen cases with refractory/relapsed AML were treated with FA regimen in which fludarabine phosphate 25 mg/(m(2) x d), d1-5; cytarabine (Ara-C) 2 g/(m(2) x d), d1-5. Another 20 cases were treated with salvage chemotherapy (MAE regimen: mitoxantrone, Ara-C and etoposide or DAE regimen: daunorubicin, Ara-C and etoposide). All patients received at least 2 cycles chemotherapy. The results showed that 9 patients (47%) in FA regimen group achieved complete remission (CR), 8 cases (42%) obtained partial remission (PR), the clinical efficacy was superior to that of the MAE or DAE regimens (p < 0.05). Major toxicity of FA regimen was myelosuppression. Grade IV hematologic toxicity occurred in all patients received FA regimen. Nonhematologic complications consisted of gastrointestinal side effects, mucositis, liver toxicity, which were mild to moderate and could be alleviated with supportive therapy. In conclusion, FA regimen is an effective regimen for treatment of refractory and relapsed AML.

[New insight into DNA methylation in CML and its effect on clinical outcome--review].

All kinds of tumors have their specific DNA methylation patterns. The study of DNA methylation changes in chronic myelogenous leukemia includes (1) the hypomethylation of carcinogenic gene, (2) the hypermethylation of tumor-suppressing gene, and (3) the hypermethylation of fusion gene. In this paper, DNA methylation change in chronic myeloid leukemia (CML) and its role in clinical stages and evaluation of prognosis were reviewed so as to illuminate the relationship between DNA methylation and CML.

[Progress of study on survivin in diffuse large B-cell lymphoma--review].

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma (NHL), which is also a significantly heterogeneous disease. Survivin, a unique member of the inhibitor of apoptosis (IAP) family, is overexpressed in various cancers, including some types of lymphoma. It is found that inhibitor of apoptosis protein, survivin, plays an important role in the development and progression of DLBCL. Survivin is able to inhibit the cell apoptosis, and enhances the cell proliferation. Many studies showed that survivin may be considered as an independent unfavorable prognostic index of DLBCL. The poor prognostic cases early are screened in combination of survivin expression with International Prognostic Index (IPI), and improve the outcome of DLBCL. Survivin selectively expressed in tumor tissue, which provide an ideal target for tumor therapy. Modulation of survivin expression or function may provide a novel approach for experimental therapy in patients with DLBCL. In this review, the progress of study on mechanism of survivin protein, the survivin expression in DLBCL, its significance in diagnosis and therapy of DLBCL, and the prospective trend were summarized.

[Correlation of cell cycle alteration to SOCS-1 gene demethylation induced by arsenic trioxide in myeloma cell lines].

BACKGROUND & OBJECTIVE: Recent studies suggest strong therapeutic potentials of arsenic trioxide (As2O3) for multiple myeloma(MM), which may be due to As2O3-induced demethylation of tumor suppressor genes. This study was to explore the correlation of cell cycle alteration to SOCS-1 gene demethylation after As2O3 induction in MM cell lines in vitro. METHODS: MM cell lines U266 and RPMI8226 were used. Cell proliferation and cell cycle of MM cells after the treatment of As2O3 were assessed by MTT assay and flow cytometry, respectively. Methylation status was detected by methylation specific PCR (MSP-PCR), and gene expression of SOCS-1 was measured by real-time PCR in MM cells before and after As2O3 treatment. RESULTS: As2O3 significantly inhibited the growth of U266 and RPMI8226 cells in a dose-dependent manner. The cell cycle of U266 and RPMI8226 were arrested at G0/G1 phase. Compared with the wild type, the percentage of cells was increased at G0-G1 phase, but decreased at S phase after the treatment of As2O3 for 72 h (P < 0.05). The mRNA expression of SOCS-1 gene was significantly increased with hemi-methylation (As2O3, 0.5 micromol/L,72 h) or complete demethylation (As2O3, 1.0 micromol/L or As2O3, 2.0 micromol/L,72 h) of the SOCS-1 gene in comparison with the wide type (P<0.05). CONCLUSIONS: As2O3 could induce cell cycle alteration of MM, which might be related to demethylation and reexpression of SOCS-1 gene in MM cell lines. The study might provide a new approach to elucidate the mechanism of the antitumor effect of As2O3 in MM.

[Arsenic trioxide induces socs-1 gene demethylation in myeloma cell lines].

The aim of this study was to explore the effect of arsenic trioxide (As(2)O(3)) on the methylation status of socs-1 gene in multiple myeloma cell lines U266, RPMI8226. The cell viability was assayed by MTT method. The methylation status of socs-1 gene was detected by methylation specific PCR. The expression of socs-1 gene mRNA was determined with real-time PCR. The cell apoptosis was analyzed by flow cytometry. The results indicated that hypermethylation of CpG island of socs-1 gene was observed without expression of socs-1 in myeloma cell lines U266, RPMI8226. The expression of socs-1 gene mRNA in each myeloma cell line increased significantly after exposure to As(2)O(3) for 72 hours as compared with the cell lines of wild type (p < 0.05). And cell proliferation was significantly inhibited, both early apoptosis and later apoptosis ratios increased in dose-dependent manner. It is concluded that As(2)O(3) may induce socs-1 demethylation and up-regulate the expression of the gene. This study provides a new thought and direction for exploring possible mechanism of cell apoptosis induced by As(2)O(3) and multiple myeloma treatment by As(2)O(3).

[cAMP analogue 8-CPT-cAMP inducing differentiation in the M2b subtype of acute myeloid leukemia cell line Kasumi-1].

This study was aimed to investigate the possible effects of cyclic adenosine monophosphate (cAMP) analogue 8-(4-chlorophenylthio) adenosine 3', 5'-cyclic monophosphate (8-CPT-cAMP) on the M(2b) subtype of acute myeloid leukemia (AML-M(2b)) cells. AML-M(2b) is characterized by the non-random chromosome translocation t (8; 21) (q22; q22), through which AML1 (acute myeloid leukemia 1) gene on chromosome 21 is fused with ETO (eight twenty-one) gene on chromosome 8, coding correspondent AML1-ETO fusion protein, which plays a crucial role in the leukemogenesis of AML-M(2b). The AML-M(2b) cell line Kasumi-1 cells were used as an in vitro model. The influences of 8-CPT-cAMP on the proliferation and differentiation of Kasumi-1 cells were evaluated according to cellular morphology, changes in cell surface antigen and cell cycle, as well as nitroblue-tetrazolium (NBT) assay. Meanwhile, semi-quantity RT-PCR and Western blot assay were used to detect the degradation of AML1-ETO fusion protein in Kasumi-1 cells before and after the treatment. The results showed that 8-CPT-cAMP (200 micromol/L) could significantly inhibit cell growth and induce differentiation of Kasumi-1 cells. However, it must be pointed out that 8-CPT-cAMP-induced differentiation in Kasumi-1 is not a typical terminal differentiation. Furthermore, 8-CPT-cAMP exerted little influence on the expression of AML1-ETO fusion gene and its product in Kasumi-1 cells. In conclusion, the 8-CPT-cAMP induced differentiation in Kasumi-1 cells. This results may provide experimental and theoretical basis for the breakthrough of differentiation-induced therapy extended to another leukemia.

[Apoptosis of multiple myeloma cells induced by 8-Cl-cAMP in vitro].

The study was aimed to investigate the possible effects of 8-chloroadenosine 3', 5'-monophosphate (8-Cl-cAMP) on the multiple myeloma cells. The multiple myeloma cell line RPMI8226 was used as in vitro models. The effect on growth inhibition of RPMI8226 cells was evaluated by cell growth and viability curve. DNA fragment was visualized by agarose gel electrophoresis. The amount of apoptosis cells was measured by flow cytometry. Meanwhile Western blot assay were used to detect the change of several key cell cycle regulatory proteins CDK2 and cyclin E in these cells before and after the treatment. The results showed that low dose 8-Cl-cAMP (1-30 micromol/L) inhibited the proliferation and viability of RPMI8226 cells significantly. Agarose gel electrophoresis of DNA revealed the apoptosis characteristic "ladder" pattern. Apoptosis was also confirmed by flow cytometry. In addition, 8-Cl-cAMP was able to inhibit the cell growth through modulating expression of cell cycle regulators CDK2 and cyclin E. It is concluded that 8-cl-cAMP inhibits the proliferation and induce apoptosis of multiple myeloma cells effectively.