Current Status in Rechallenge of Immunotherapy.

The treatment of malignant tumors has entered the era of immunotherapy, and immune checkpoint inhibitors (ICIs) have brought significant benefits to patients. However, some patients are required to discontinue treatment with ICIs owing to factors such as disease progression and intolerable side effects. Faced with limited subsequent treatment options and complex medical needs, we searched PubMed, Embase, Cochrane library, and the NIH clinical trials database and found that ICI rechallenge could be a relevant clinical strategy. The factors that could affect the rechallenge efficacy include the patients' characteristics, therapeutic strategy selection, and the timing of treatment. Multiple factors are used to identify target population, of which clinical features and PD-L1 expression are more potential. Both single ICI rechallenge and combination therapy may have survival benefits. Patients who have tolerated initial immunotherapy well could undergo ICI rechallenge, while patients who have experienced grade 3 or higher immune-related adverse events should be carefully assessed prior to rechallenge. Interventions and the interval between two courses of ICI will clearly have an impact on the efficacy of subsequent treatment. Preliminary data evaluation supports further investigation on ICI rechallenge to identify the factors that could contribute to its efficacy.

Overexpression of MPC1 inhibits the proliferation, migration, invasion, and stem cell-like properties of gastric cancer cells.

Invasion and metastasis are major malignant characteristics of human gastric cancer (GC), but the molecular mechanisms underlying the invasion and metastasis of GC cells remain elusive. MPC1, a key factor that controls pyruvate transportation through the inner mitochondrial membrane, was reported to be downregulated and correlated with poor prognosis in several cancers. However, the effects of MPC1 on human GC have not been illustrated. In this study, we investigated the potential role of MPC1 in the proliferation, migration, invasion, and stem cell-like properties of human GC cells and evaluated its prognostic significance for patients with GC. We found that MPC1 protein and mRNA levels were significantly decreased in GC tissues and cell lines. Low MPC1 expression was associated with tumor T stage, N stage, and advanced tumor node metastasis stage. Decreased MPC1 expression was an independent prognostic marker and correlated with poor overall survival of patients with GC. Furthermore, overexpression of MPC1 inhibited the proliferation, migration, invasion, and stem cell-like properties of GC cells. These findings suggest that MPC1 may be a novel prognostic marker and a potential therapeutic target in human GC.

Efficacy and tolerance of pegaspargase, gemcitabine and oxaliplatin with sandwiched radiotherapy in the treatment of newly-diagnosed extranodal nature killer (NK)/T cell lymphoma.

Extranodal nature killer (NK)/T cell lymphoma (ENKL), nasal type, is a highly aggressive and heterogeneous disease. Here we report a retrospective study of 38 newly-diagnosed ENKL patients treated with pegaspargase, gemcitabine, oxaliplatin (P-Gemox) and sandwiched radiotherapy in our department during 2012-2016. A median of 4 (range, 2-6) (total=141) cycles of P-Gemox were administered. Interim restaging after at least 2 cycles showed complete remission (CR) rate of 23.68%, partial remission (PR) rate of 63.16%, giving an overall response rate (ORR) of 86.84%. On treatment completion, the ORR became 92.1% (CR=86.84%, PR=5.26%). Only one patient experienced disease progression during therapy. Multivariate analysis showed gender was a significant independent factor impacting on CR. Hematologic toxicity was common yet nonhematologic toxicity was mild, both of them can be well controlled by supportive treatments and only one treatment-related death was observed. At a median follow-up of 15.5 months, 4 patients (10.53%) experienced disease progression and died of disease. 1-year progression-free survival (PFS) rate and 1-year overall survival (OS) rate for the whole cohort were 86.7% and 86.6%. The P-Gemox regimen with sandwiched radiotherapy may be a promising option in the treatment of newly-diagnosed ENKL due to its high efficacy yet low toxicity.

A novel zinc finger protein Zfp637 behaves as a repressive regulator in myogenic cellular differentiation.

Zinc finger proteins have been implicated as transcription factors in the differentiation and development of cells and tissues in higher organisms. The classical C2H2 zinc finger motif is one main type of motif of zinc finger proteins. Our previous studies have shown that Zfp637, which comprises six consecutively typical and one atypical C2H2 zinc finger motifs, is highly expressed in undifferentiated or poorly differentiated cell lines, but is moderately or slightly expressed in normal tissues. We have also demonstrated that Zfp637 can promote cell proliferation. However, its role in the regulation of cell differentiation remains unknown. We report here that endogenous Zfp637 as well as mTERT is expressed in proliferating C2C12 myoblasts and that their expression is downregulated during myogenic differentiation. Constitutive expression of Zfp637 in C2C12 myoblasts increased mTERT expression and telomerase activity, and promoted the progression of the cell cycle and cell proliferation. By contrast, endogenous repression of Zfp637 expression by RNA interference downregulated the mTERT gene and the activity of telomerase, and markedly reduced cell proliferation. Overexpression of Zfp637 also inhibited the expression of myogenic differentiation-specific genes such as MyoD and myogenin, and prevented C2C12 myoblast differentiation. Our results suggest that Zfp637 inhibits muscle differentiation through a defect in the cell cycle exit by potentially regulating mTERT expression in C2C12 myoblasts. This may provide a new research line for studying muscle differentiation.

Antitumor effect of lung cancer vaccine with umbilical blood dendritic cells in reconstituted SCID mice.

Dendritic cells (DCs) are important cells in initiating an immune response. A generation of functional DCs has potential clinical use in treating cancer. However, the source of DCs and patient immunodeficiency with cancer have been hindrances in clinical therapy. We generated DCs from human umbilical cord blood mononuclear cells (UBMCs) with recombinant human granulocyte-macrophage colony stimulating factor, recombinant human interleukin-4, and recombinant human tumor necrosis factor-alpha. The mature DC-A549 lung cancer vaccine (AgL-DC) was prepared through loading A549 lysate, treating with lipopolysaccharide (LPS) and positive selecting with CD83 magnetic beads. AgL-DC can secrete interleukin (IL)-12 and IL-1. Further in vitro analysis showed that AgL-DC notably induced human UBMC lymphocyte proliferation (p < 0.01) by 3-(4,5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, increased the cytotoxic T-lymphocyte (CTL) activity of UBMC lymphocytes against A549 cells (p < 0.05, at effector cells:target cells ratios of 50:1 and 100:1) by lactate dehydrogenase (LDH) cytotoxic assay, and improved production of IL-6 and tumor necrosis factor-beta (p < 0.01, p < 0.05) by enzyme-linked immunosorbent assay. Subsequently, the reconstitute immunity model in severe combined immunodeficiencies (SCID) mice has been established using human UBMC transplantation, and similar trends to results of UBMC in vitro experiments have been shown in lymphocyte proliferation, CTL activity, and IL-6 and tumor necrosis factor-beta secretion levels in these models. AgL-DC also significantly (p < 0.01) increased the antitumor effect in vivo. The tumor infiltrating immunocytes were positively expressed human CD83 and CD3 molecules, and they were negatively expressed in tumor tissue treated with control. These results have demonstrated that umbilical cord DCs are a useful source of vaccine cells for augmenting CTL-mediated cytotoxicity and have potential usefulness in cellular therapy for human cancer in a new vaccination strategy.

[Construction of eukaryotic expression plasmid pEGFP-ATP1B1 and its effect on gastric adenocarcinoma cell SGC-7901].

OBJECTIVE: To establish the eukaryotic expression plasmid containing the code gene of Na+, K+-ATPase beta1-subunit (ATP1B1) and the basis of ATP1B1 applied to antitumor gene therapy. METHODS: The ATP1B1 cDNA was amplified from leukocyte gene library and then cloned into the eukaryotic expression vector pEGFP-C3. The recombinant plasmid, named as pEGFP-ATP1B1, was determined with restriction enzyme and sequencing analyses. Next pEGFP-ATP1B1 was transferred into gastric adenocarcinoma SGC-7901 cells by lipofectamine, then ATP1B1 mRNA expression in transfected cells was detected by real-time PCR, and also ATPase was detected after cell transfection, as well as the proliferation of such cells was measured by MTT. RESULTS: The analysis confirmed that the recombinant pEGFP-ATP1B1 contained the ATP1B1 cDNA. After cell transfection, the expression of ATP1B1 mRNA(129.2%) and the activity of ATPase [(2.95+/-0.210)%] were higher, and the growth of the SGC-7901 cells transfected with ATP1B1 was inhibited obviously when compared with the control group. CONCLUSION: The recombinant pEGFP-ATP1B1 is constructed successfully, and this recombinant eukaryotic expression vector could be used in additional studies on the biological effect of ATP1B1 and its use in anti-tumor gene therapy.

[Interaction between member LIGHT of TNF superfamily and SOCS3, which respond to induce the differentiation and maturation of dendritic cell].

OBJECTIVE: To detect the relation between the member LIGHT of TNF superfamily and the suppressor of cytokine signaling 3 (SOCS3), and to investigate the effect of SOCS3 on dendritic cell (DC) maturation induced by LIGHT. METHODS: Bone marrow-derived DC (BMDC) was generated from mouse bone marrow monocyte by culturing with rmGM-CSF, rmIL-4 in vitro. SOCS3 mRNA in BMDC was analyzed by RT-PCR, and the protein of SOCS3 was measured by Western blot. After blocking the SOCS3 expression with the specific anti-sense oligonucleotide, we applied the flow cytometry to measure the expression of CD86 and CD40 on DC for making clear whether the silence of SOCS3 would regulate the LIGHT-stimulated DC maturation. RESULTS: With the effect of LIGHT, the level of SOCS3 mRNA and protein in BMDC sharply increased. The specific antisense oligonucleotide could effectively block SOCS3 mRNA expressing in BMDC with the ratio of 49% and block SOCS3 protein expression with the ratio of 45%. Compared with SOCS3-unblocked DC, the SOCS3-blocked BMDC with stimulation of LIGHT showed higher CD40 and CD86 (P < 0.05). CONCLUSION: LIGHT enhances the expression of SOCS3 during stimulating BMDC maturation. As more sensitive to LIGHT, the SOCS3-blocked BMDC is driven to more mature. SOCS3 presents a negative regulation mechanism in BMDC maturation induced

[Growth inhibition and multidrug resistance-reversing effect of tanshinone I A on human breast cancer cell with estrogen receptor negative].

OBJECTIVE: To investigate the growth inhibition and multidrug resistance (MDR) reversing effect of tanshinone I A on human breast cancer cells with estrogen receptor (ER) negative, and to elucidate its mechanism of activity. METHODS: Human ER negative breast cancer cells (MDA-MB-231) were tested in vitro for cytotoxicity and colony formation inhibition. Brdu incorporation and cell cycle distribution were also checked through flow cytometry (FCM). With RT-PCR, the expressions of ADP-ribosyltransferase CNAD+; poly (ADP-ribose) polymerase)-like 1 (ADPRTL1), cytochrome P450 subfamily I (CYP1A1) and breast cancer resistance protein (BCRP/ABCG2) mRNA were detected for testing the response to tanshinone 1 A treatment. RESULTS: After tanshinone I A treatment, the proliferation, colony formation and Brdu labeling indices of cancer cells decreased (P<0. 05). By FCM analysis, the increase of subG, and G0/G1 phase cell populations and decrease of S and G2/M phase cells were observed (P