The human ovarian cell line A2780 was exposed to either cisplatin (10 ,uM) or 5-fluorouracil (5FUra) (5 ,uM) for 1 hr. Cytotoxicity was less than 14% with either agent alone. Cisplatin (10 j#M) and 5FUra (5 jzM) in combination for 1 hr caused a 76% reduction in cell growth. Thymidine (dThd, 10 jM), if given concomitantly with the combination of cisplatin and 5FUra. completely protected the tumor cells. A 30-min exposure to cisplatin increased the intracellular pools of 5,10-methylenetetrahydrofolate and tetrahydrofolate 2.5-fold.The capacity of intact cells to form 5-fluorodeoxyuridylate (FdUMP)-thymidylate (dTMP) synthase complex when incubated with fluorodeoxyuridine (FdUrd) was enhanced 2.5-fold when the cells were pretreated with cisplatin. These experiments demonstrate that cisplatin can increase the availability of the reduced folate necessary for tight binding of FdUMP to dTMP synthase, thus enhancing the cytotoxicity of the cisplatin and 5FUra combination.5-Fluorouracil (5FUra) and cis-diamminedichloroplatinum-(II) (cisplatin) in combination have been shown to have synergistic cytotoxicity against both murine and human neoplasms (1, 2). The mechanism ofthis synergy has not been elucidated. SFUra is metabolized within cells to 5-fluorodeoxyuridine monophosphate (FdUMP). FdUMP can covalently bind to dTMP synthase in the presence of 5,10-methylenetetrahydrofolate (CH2-H4folate) and inhibit DNA synthesis by depleting the cells of dTMP. 5FUra is also metabolized to 5-fluorouridine triphosphate (FUTP), which is incorporated into RNA. One or both of these 5FUra metabolites account for the antineoplastic activity of SFUra in experimental models (3). The antitumor activity of the second agent, cisplatin, may be explained in part by DNA crosslinking (4, 5), interactions with the cell-surface nucleic acids (6) or with the plasma membrane (7-9). Also, cisplatin can inhibit methionine uptake into tumor cells and cause perturbation of the methionine pools (7-9). Cells may respond by increasing methionine biosynthesis and increasing the pools of folate cofactors (10). The interaction of these two chemotherapeutic drugs was studied in patients with human ovarian cancer (11). Data presented in this report suggest that cisplatin treatment does increase the CH2-H4folate pool and the binding of FdUMP to dTMP synthase. The resultant inhibition of dTMP synthesis appears to be responsible for the cytotoxicity of the SFUra and cisplatin combination. MATERIALS AND METHODSThe following chemicals were obtained from these companies: thymidine, Sigma; SFUra, Hoffmann-La Roche; deoxyuridine, P-L Biochemicals; cisplatin and 5-fluorodeoxy- Cell Culture. The human ovarian cancer cell line A2780 was obtained from R. Ozols, National Cancer Institute (12) and maintained in RPMI 1640 with 10% (vol/vol) fetal calf serum, penicillin (62.9 mg/liter) and streptomycin (100 mg/ liter) (GIBCO). Cells were exposed to chemotherapeutic agents for only 60 min in RPMI 1640 medium and 10% (vol/vol) fetal calf serum and then washed three times wi...

Purpose: CD19-specific chimeric antigen receptor (CAR) T-cell therapy is effective against refractory or relapsed (R/R) B-cell lymphoma, but the efficacy is hindered by the existence of PD-1/PD-L1 pathway. Patients and Methods: Here, we generated a novel anti-CD19 CAR-expressing PD-1/CD28 chimeric switch-receptor (CD19-PD-1/CD28-CAR). We then conducted a phase Ib study to evaluate safety and efficacy of CD19-PD-1/CD28-CAR T cells in the treatment of PD-L1+ B-cell lymphoma. Results: We found that CD19-PD-1/CD28-CAR T cells had superior T-cell proliferation, cytokine production, and sequentially capability of killing PD-L1+ B-cell lymphoma cells in vitro and in vivo relative to the prototype, CD19-CAR T cells. Among 17 adult patients with R/R lymphoma who received the CAR T therapy, 10 patients had objective response (58.8%), including seven patients with complete remission (41.2%). At a median follow-up 15 months, median overall survival for all patients was not reached. Remarkably, no severe neurologic toxicity or cytokine release syndrome was observed. Conclusions: This first-in-human study demonstrates the tolerability, safety, and encouraging efficacy of CD19-PD-1/CD28-CART in PD-L1+ large B-cell lymphoma.

Tumor endothelial marker 8 (TEM8) was discovered as a cell membrane protein that is predominantly expressed in tumor endothelium and identified as a receptor for anthrax toxin. We developed an antibody-like molecule that consists of the protective antigen (PA)-binding domain of human TEM8 linked to the Fc portion of human immunoglobulin G1 (TEM8-Fc). This engineered protein bound to PA in a divalent cation-dependent manner and efficiently protected J774A.1 macrophage-like cells against anthrax toxin challenge in a dose-dependent manner. TEM8-Fc suppressed the growth and metastasis of xenograft human tumors in athymic nude mice (control versus 10 mg/kg TEM8-Fc, mean tumor weight: LS-180, 1.72 versus 0.16 g, difference = 1.56 g, 95% confidence interval [CI] = 0.96 to 2.16 g; P<.001; MCF-7, 1.12 versus 0.08 g, difference = 1.04 g, 95% CI = 0.77 to 1.31 g; P<.001; HepG2, 1.28 versus 0.35 g, difference = 0.93 g, 95% CI = 0.60 to 1.25 g; P<.001). Furthermore, TEM8 interacted with the M2 isoenzyme of pyruvate kinase (M2-PK), which has an important role in tumor growth and metastasis. TEM8-Fc is a novel therapeutic antibody-like agent in the management of solid tumors that may act by trapping M2-PK.

Therapy-related acute lymphoblastic leukemia (t-ALL) is a rare secondary leukemia following chemotherapy and/or radiotherapy for primary malignancies. Chromosomal 11q23 abnormality, frequently detected in therapy-related acute myeloid leukemia, is the most common cytogenetic alteration in t-ALL. However, t-ALL cases without 11q23 abnormality have been rarely described. We describe 6 adults with secondary t-ALL without 11q23 abnormalities following various treatment regimens for primary malignancies. We also reviewed 48 t-ALL cases, with complete chromosomal karyotyping, reported in the literature from 1992 to 2007. In the 48 cases, an 11q23 abnormality involving the MLL gene locus was the predominant chromosomal aberration (32 [67%]), followed by t(9;22) (6 [13%]) and a normal karyotype (4 [8%]). Compared with t-ALL cases with an 11q23 abnormality, cases without an 11q23 abnormality had a relatively longer latency period (median, 36 vs 19 months) and a different primary malignancy spectrum. No major difference was observed between groups in regard to age, sex, or receipt of a topoisomerase II inhibitor. The t(8;14)(q11.2;q32), a rare, nonrandom, balanced chromosomal translocation differing from the more common translocation involving c-MYC on chromosome 8q24, was seen in 1 adult t-ALL case, which may suggest another possible pathogenesis of this disease.

Type 1 diabetes mellitus is caused by T-cell-mediated autoimmune destruction of pancreatic β-cells. Systemic administration of mesenchymal stem cells (MSCs) brings about their incorporation into a variety of tissues with immunosuppressive effects, resulting in regeneration of pancreatic islets. We previously showed that human MSCs isolated from Wharton's jelly (WJ-MSCs) represent a potential cell source to treat diabetes. However, the underlying mechanisms are unclear. The purpose of this study was to discern whether undifferentiated WJ-MSCs can differentiate into pancreatic insulin-producing cells (IPCs) and modify immunological responses in nonobese diabetic (NOD) mice. Undifferentiated WJ-MSCs underwent lentiviral transduction to express green fluorescent protein (GFP) and then were injected into the retro-orbital venous sinus of NOD mice. Seven days after transplantation, fluorescent islet-like cell clusters in the pancreas were apparent. WJ-MSC-GFP-treated NOD mice had significantly lower blood glucose and higher survival rates than saline-treated mice. Systemic and local levels of autoaggressive T-cells, including T helper 1 cells and IL-17-producing T-cells, were reduced, and regulatory T-cell levels were increased. Furthermore, anti-inflammatory cytokine levels were increased, and dendritic cells were decreased. At 23 days, higher human C-peptide and serum insulin levels and improved glucose tolerance were found. Additionally, WJ-MSCs-GFP differentiated into IPCs as shown by colocalization of human C-peptide and GFP in the pancreas. Significantly more intact islets and less severe insulitis were observed. In conclusion, undifferentiated WJ-MSCs can differentiate into IPCs in vivo with immunomodulatory effects and repair the destroyed islets in NOD mice.

MicroRNAs (miRNAs) are non-coding single-stranded RNAs with about 21~23 nucleotides in length, which originate from encoding genes in nucleus. miRNAs play an inhibitory role in gene expression in a post-transcriptional level by partially complementary binding to the 3' unstranlated region (UTR) of target mRNAs. Large bodies of evidence have shown that miRNAs were involved in various diseases, such as cancer, infectious diseases, diabetes etc, and rising as critical modulators of pathological processes. Lately, some highlight articles revealed that the altered expression of miRNAs such as miR-1, miR-133, miR-21, miR-208 etc in hearts also contributed to cardiovascular diseases, such as heart ischemia, cardiac hypertrophy, and arrhythmias. Moreover, miRNAs were also identified to regulate heart development. These exciting findings not only improve our understanding of the molecular mechanisms of heart diseases, but also provide a new class of potential molecular targets. miRNAs, for the development of novel agents to treat heart diseases. Here, we summarized the recent discoveries about the role of miRNAs in cardiac physiological and pathological functions, and then discussed about their therapeutic potentials for heart diseases.

No abstract

Salvianolic acid A (SAA), one of the main derivatives of Salvia miltiorrhiza, has been shown to possess anti-inflammatory and anti-thrombotic activities. Its role in inhibiting tumor growth, however, remains elusive. The aim of this study was to investigate the effect of SAA on acute myeloid leukemia (AML). Here, SAA showed a dose-dependent cell viability inhibition and apoptosis induction in AML cells. At the molecular level, SAA increased the expression of Bak and decreased the expression of Bcl-xL, following by PARP cleavage and caspase-3 activation. SAA also markedly attenuated Akt phosphorylation in AML cells. In a xenograft mouse model, SAA significantly suppressed the growth of AML tumors in vivo. Furthermore, SAA exhibited a more profound pro-apoptotic effect on primary AML cells than on bone marrow mononuclear cells from patients with benign diseases. Therefore, the pro-apoptotic and anti-tumor properties of SAA suggested its promising therapeutic value for AML.