The nuclear transportation of PD-L1 and the function in tumor immunity and progression.

As the main immune checkpoint, PD-L1-PD-1 interaction plays a critical role in the dysregulation of effector T cells, which contributes to the failure of Chimeric Antigen Receptor T-cell (CAR-T) and other immunotherapies. Presently, most research focuses on the extracellular function of PD-L1. Membrane PD-L1 can interact with its receptor PD-1 and decrease T cell-induced cancer immunity. However, the function of PD-L1 in cancer cells is still unclear. Recent studies have shown the separated clinical significance of PD-L1 expression in various cancer types, showing the complexity of PD-L1 in cancer cell regulation. As a novel regulatory pathway, the nuclear translocation of PD-L1 in cancer cells receives more attention. Results of these preclinical studies demonstrated that nuclear PD-L1 has an essential role in cancer development and other immune checkpoint molecules transcription. Herein, we summarized the mechanisms involved in PD-L1 nuclear transportation and identify the key regulatory factors in this process. Furthermore, we also summarize the function of nuclear PD-L1 in cancer immunity. These findings suggested the novel PD-L1 regulation in cancer development, which showed that nuclear PD-L1 is a potential therapeutic target in future cancer therapy.

Differential expression of circular RNAs in plasma exosomes from patients with ankylosing spondylitis.

Exosomes are being extensively studied as a source of valuable new biomarkers. The underlying mechanism of ankylosing spondylitis (AS) may include changes in the circular RNAs (circRNAs) of exosomes. However, there is a lack of reports on the role of exosomal cirRNAs in the plasma of patients with AS. We isolated exosomes from the plasma of patients with AS and healthy individuals (controls). Subsequently, we investigated the circRNA profiles of the exosomes via high-throughput RNA sequencing and identified 56 differentially expressed circRNAs in the exosomes of patients with AS compared with those of the healthy controls. Gene Ontology demonstrated that the differentially expressed circRNAs were mainly involved in the negative regulation of the activity of the transcription factor nuclear factor-κB and bone remodelling that is potentially related to AS. Kyoto Encyclopedia Genes and Genome demonstrated that the most highly AS-correlated pathways that were identified were 'notch signalling pathway' and those primarily involved with 'cholinergic synapse'. Finally, we validated five differentially expressed circRNAs using quantitative real-time polymerase chain reaction and predicted their potential functions through the circRNA-miRNA-mRNA network. Our study is the first to report changes in exosomal circRNAs from plasma samples of patients with AS, and provide novel targets for further investigation of molecular mechanisms and potential intervention therapy targets of AS.

Histoplasmosis mimicking metastatic spinal tumour.

Histoplasmosis is an infection caused by a fungus called Histoplasma. Diagnosis of histoplasmosis is based on the culture of biological samples and detection of fungus in tissues. Histoplasmosis can mimic malignant lesions. We report a 65-year-old, immunocompetent, male patient with back pain. We describe the main clinical and radiological characteristics in our patient who had vertebral histoplasmosis that mimicked cancer. A computed tomography scan showed lytic lesions of the right side of T4, T5, and T6 vertebral bodies. Magnetic resonance imaging displayed abnormal marrow signals in T4, T5, and T6 vertebral bodies (low signal on T1, high on T2 and short time inversion recovery (STIR)). Which was mimicking malignancy, such as haematological malignancy and metastatic bone cancer. Therefore, thoracic spinal surgery using the anterior approach was performed. An intraoperative frozen section examination and routine postoperative pathology showed thoracic histoplasmosis infection. Treatment of histoplasmosis was performed with oral itraconazole. The lesions did not progress and the patient symptomatically improved at a follow-up of 26 months.

Celecoxib enhances anticancer effect of cisplatin and induces anoikis in osteosarcoma via PI3K/Akt pathway.

BACKGROUND: COX-2, an inducible enzyme, is associated with inflammatory diseases and carcinogenesis. Overexpression of COX-2 occurs in many human malignancies, including osteosarcoma. COX-2 positivity is form 67 to 92% in osteosarcoma, and COX-2 expresses 141-fold more in cancer stem cell spheres than daughter adherent cells. In our study, we have reported that celecoxib, a cyclooxygenase-2 inhibitor, induces apoptosis in human osteosarcoma cell line MG-63 via down-regulation of PI3K/Akt. It has been confirmed that celecoxib enhances apoptosis and cytotoxic effect of cisplatin, although the mechanism remains unclear. METHODS: We have attempted to identify the anti-proliferation of celecoxib, a selective COX-2 inhibitor, and the combination of celecoxib and cisplatin in MG-63 cells, and to explore the potential molecular mechanisms involved. MG-63 cells were treated with the combination of celecoxib and cisplatin or either agent alone for 48 h in serum-supplemented medium. RESULTS: MDR1, MRP1, BCRP and Trkb, E-cadherin, ß-catenin were significantly downregulated in cells treated with the combination of celecoxib and cisplatin, and decreased ß-catenin level was found in cells with wortmannin, a specific PI3K inhibitor. CONCLUSION: Therefore, celecoxib enhances anticancer effect of cisplatin and induces anoikis in osteosarcoma, which may be PI3K/Akt-dependent, and MDR and ß-catenin-related. PI3K may be at the center of the celecoxib effects, which play an essential role in the regulation of MDR and anoikis.

The complete mitochondrial genome sequence and gene organization of Ambassis gymnocephalus (Perciformes, Ambassidae).

In this study, we firstly obtained the complete mitochondrial genome DNA sequence of the Ambassis gymnocephalus. Its length is 17,388 bp, containing 13 protein-coding genes, 2 rRNAs, 22 tRNAs and a large noncoding region. The overall length of protein coding genes is 11,448 bp, including A (26.75%), G (15.20%), T (26.44%) and C (31.61%). The A + T content of control region (1555 bp) is 60.45%. The protein-coding gene COI is started by GTG and ended by AGA. From the phylogenetic tree, we find A. gymnocephalus and Oreochromis niloticus has the closest relationship among 21 related species. This work will provide some valuable information for further studies on A. gymnocephalus and the family Ambassidae.

The complete mitochondrial genome of Stolephorus commersonii.

In this study, the complete mitochondrial genome of Stolephorus commersonii is determined. It is 16,734 bp in length and consists of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a control region. Phylogenetic tree was constructed based on the complete mitogenome of S. commersonii and closely related 17 other species to assess its phylogenic relationship and evolution. The findings of the study will contribute to the phylogenetic classification and the genetic conservation management of S. commersonii.

Complete mitochondrial genome and phylogenetic position of Chaenodraco wilsoni.

Chaenodraco wilsoni, a species of Channichthyidae, inhabits in southern ocean. The total length of complete mitochondrial genome of C. wilsoni is 17,432 bp, which encoded 37 genes. Similar to most Antarctic fishes, the ND6/tRNA (glu) translocation and an additional non-coding region linked with ND6 have also occurred in C. wilsoni. The ML tree supports that C. wilsoni has closer relationship with Chionodraco species. Our research will provide more molecular biology information about C. wilsoni and deepen the understanding of Antarctic fishes.

[Advances in Bevacizumab Therapy for Non-small Cell Lung Cancer 
with Brain Metastases].

Brain metastases are frequently encountered in patients with non-small cell lung cancer (NSCLC) and are a significant cause of morbidity and mortality. Antiangiogenesis therapy plays a major role in the management of brain metastases in lung cancer. Bevacizumab have become the novel method for the treatment of lung cancer with brain metastases beyond the whole brain radiation therapy, stereotactic radiosurgery and chemotherapy. Recently, more and more studies and trials laid emphasis on the bevacizumab for NSCLC with brain metastases treatment. The key point is the efficacy and safety. In this review, bevacizumab therapy of NSCLC with brain metastases were summarized.

Cyclooxygenase-2 promotes tumor growth and suppresses tumor immunity.

Cyclooxygenase-2 (COX-2), an inducible form of the enzyme that catalyzes the first step in the synthesis of prostanoids, is associated with inflammatory diseases and carcinogenesis, which is suspected to promote angiogenesis and tissue invasion of tumors and resistance to apoptosis. Meanwhile, COX-2 contributes to immune evasion and resistance to cancer immunotherapy, which plays a crucial role in the innate and adaptive immune response. The activity of COX-2-PGE2-EP signal pathway can suppress Dendritic cells (DCs), natural killer (NK), T cells, type-1 immunity excluding type-2 immunity which promote tumor immune evasion. COX-2 and the prostaglandin cascade play important roles in the "inflammogenesis of cancer". In addition, COX-inhibitors can inhibit tumor immune evasion. Therefore, we can exert the COX-inhibitors to facilitate the patients to benefit from addition of COX-inhibitors to standard cytotoxic therapy.

Cyclooxygeanse-2 promotes metastasis in osteosarcoma.

Cyclooxygenase-2 (COX-2), an inducible form of the enzyme that catalyzes the first step in the synthesis of prostanoids, is associated with carcinogenesis, which is suspected to promote angiogenesis and tissue invasion of tumors and resistance to apoptosis. COX-2 is also involved in metastasis and poor prognosis of cancer. Osteosarcoma with COX-2 positivity is from 67 to 92 %. COX-2-positive rate in metastatic lesions was greater than that of biopsy and/or resected samples of the primary site in osteosarcoma. And, what role does COX-2 play in osteosarcoma metastasis? Genetic studies support a cause-effect connection between COX-2 and tumorigenesis. COX-2 expression had a poor prognosis with regard to metastasis, and patients with increased COX-2 expression in lung metastases died of the disease. COX-2 expression has also been established as a marker in human osteosarcoma, and COX-2 inhibition has been suggested as a possible way of improving therapeutic outcome. In addition, COX-inhibitors inhibit the tumor initiation, matrix metalloproteinases (MMPs), cell differentiation and T cell proliferation and suppression of the antitumor activity of natural killer cells and macrophages, angiogenic mechanism. Therefore, we can exert the COX-inhibitors to potentialize the effects of chemotherapeutic agents, and reverse the metastasis in osteosarcoma to facilitate the patient who may benefit from addition of COX-inhibitors to standard cytotoxic therapy.

Cyclooxygenase-2 inhibitors induce anoikis in osteosarcoma via PI3K/Akt pathway.

COX-2, an inducible enzyme, is associated with inflammatory diseases and carcinogenesis. Overexpression of COX-2 occurs in many human malignancies, including osteosarcoma. In our study, we reported that Celecoxib, a cyclooxygenase-2 inhibitor, induces apoptosis in human osteosarcoma cell line MG-63 via down-regulation of PI3K/Akt. PI3K/Akt plays an essential role in the cell/extracellar matrix (ECM) and cell/cell adhesion. We hypothesize that COX-2 inhibitors induce anoikis in osteosarcoma via PI3K/Akt, resulted in lack of correct attachment and the down-regulations of ß-catenin, TrkB and E-cadherin, which play an essential role in the cell/extracellar matrix (ECM) and cell/cell adhesion. Meanwhile, apoptosis also be disclosed, such as DNA fragments and apoptotic bodies, activation of caspase-8, 9 and cleavage of PARP. With wortmannin, a specific PI3K inhibitor can simulate the effect of COX-2 inhibitors. If our hypothesis is correct, COX-2 inhibitors could cut down the occurrence of metastasis and facilitate the patient who may benefit from addition of COX-2 inhibitors to standard cytotoxic therapy.

[Nrf2 down-regulated cell line H460-N5 with Keap1 over-expression increased sensitivity to anti-cancer drugs].

OBJECTIVE: To maked a Nrf2 down-regulated cell line by over-expressing Keap1 in H460 cells to study the role of Nrf2 in drug resistance. METHODS: Transfecting H460 cells with mKeap1-pEGFP and screenig for Keap1 expressing clones by Western blotting with antibodies against Nrf2, HO-1, NQO1 and AKR1C. The cell line with Keap1 over-expression was further confirmed by real-time PCR. The cytotoxicity of H460-N5 to anti-cancer drugs was evaluated by MTS assay. RESULT: MTS assay results showed the enhanced cytotoxicity of anticancer drugs (Oxaliplatin, Doxorubicin and Etopside) to the H460 cell line with keap1 overexpression compared to the control cell line. In H460-N0 cells, the IC(50) values of Oxaliplation and Etopside were 93 micromol/L and 100 micromol/L respectively whereas the IC(50) values of the two drugs were 42 micromol/L and 30 micromol/L correspondingly in H460-N5 cells. A Nrf2 down-regulated cell line H460-N5 and a control cell line with GFP over-expression have been identified.Down-regulation of Nrf2 enhanced the cytotoxicity of Oxaliplatin, Doxorubicin and Etopside. The IC(50) value of Doxorubicin to H460-N0 cell was above 3 mg/L, but that to H460-N5 cell was about 2 mg/L. CONCLUSION: A Nrf2 down-regulated cell line H460-N5 and a control cell line with GFP over-expression have been identified. Down-regulation of Nrf2 enhanced the cytotoxicity of Oxaliplatin, Doxorubicin and Etopside.

[Effect of tBHQ and sulforaphane on Nrf2-ARE signaling pathway of Caco2 cells].

OBJECTIVE: To investigate the effect of tBHQ and sulforaphane on the protein expression in Nrf2-ARE signaling pathway of Caco2 cells. METHODS: Human colorectal carcinoma Caco2 cells were treated with 20 micromol/L tBHQ and 5 micromol/L sulforaphane (SFN) respectively. Real time PCR, Western blotting and immunoflourescence staining (IF) were performed to measure the target gene expression. RESULTS: Nrf2, AKR1C1 and NQO1 protein expressions were increased time-dependently in Caco2 cells after treatment with tBHQ and SFN. Time-course experiments showed that tBHQ and SFN increased the accumulation of Nrf2, and concomitantly increased the protein levels of AKR1C1 and NQO1. Real-time PCR and Western blotting showed that tBHQ and SFN significantly increased the expression of Nrf2 at 8h after the treatment, and AKR1C1 and NQO1 at 16 h. Confocal microscopy technique showed that Nrf2 accumulated in the nucleus at 6-8 h after treatment with tBHQ. After 1 h treatment with tBHQ the nuclear Nrf2 maintained at elevated level for at least 4 h with tBHQ withdrawn. CONCLUSION: tBHQ and SFN induced nuclear accumulation of Nrf2 and activated Nrf2-dependent regulation of ARE-mediated gene expression in Caco2 cells. In addition, the results provide experimental evidence for choosing the dose and frequency of the inducer in cancer chemoprevention study and in developing inhibitors of Nrf2-ARE signaling pathway.

[Effect of DRB/alpha-Amanitin on localization of Nrf2 in A549 cells].

OBJECTIVE: To investigate the effects of transcriptional inhibitors 5, 6-dichloro-1-b-D-ribofuranosylbenzimidazole (DRB) and alpha-Amanitin on the localization of Nrf2 in the nucleus. METHODS: A549 cells were treated with DRB (50 mg/L) or alpha-Amanitin (2.5 mg/L)for 1 h and 6 h in serum-free medium, respectively. The expressions of Nrf2, HO-1, NQO1 and AKR1C were detected by Western blotting analysis. The localization of Nrf2 was determined by laser scanning confocal microscopy after cells were treated with either DRB or agr:-Amanitin for 1 h. RESULTS: The expressions of Nrf2 and Nrf2-ARE gene batteries HO-1, AKR1C and NQO1 were decreased after 6 h treated with either DRB or alpha-Amanitin. The expression of SC35 was up-regulated but RNA Pol II was down-regulated; Y12 and NPC did not significantly change. The localization of Nrf2 in the cell nucleus did not change significantly. CONCLUSION: DRB and alpha-Amanitin can down-regulate the expression of Nrf2 and its targeting proteins HO-1, AKR1C and NQO1, but may have no effect on the localization of Nrf2.

Bexarotene: a promising anticancer agent.

Retinoids are biologically active derivatives of vitamin A, which play essential roles in embryonic or adult cell behavior modulating cell proliferation, differentiation and apoptosis. The biologic effects of retinoids are mediated by two distinct families of intracellular receptors: retinoid acid receptors (RARs)-α, -ß and -γ and retinoid X receptors (RXR)-α, -ß and -γ. Bexarotene is a selective RXR agonist, which exerts its effects in blocking cell cycle progression, inducing apoptosis and differentiation, preventing multidrug resistance, and inhibiting angiogenesis and metastasis, making it a promising chemopreventive agent against cancer.

Cyclo-oxygenase 2 up-regulates the effect of multidrug resistance.

COX-2 (cyclo-oxygenase 2), an inducible form of the enzyme that catalyses the first step in the synthesis of prostanoids, is associated with inflammatory diseases and carcinogenesis, which is suspected to promote angiogenesis and tissue invasion of tumours and resistance to apoptosis. COX-2 is also involved in drug resistance and poor prognosis of many neoplastic diseases or cancers. The activation of the COX-2/PGE2 (prostaglandin E2)/prostaglandin E receptor signal pathway can up-regulate the expression of all three ABC (ATP-binding-cassette) transporters, MDR1/P-gp (multidrug resistance/P-glycoprotein), MRP1 (multidrug-resistance protein 1) and BCRP (breast-cancer-resistance protein), which encode efflux pumps, playing important roles in the development of multidrug resistance. In addition, COX inhibitors inhibit the expression of MDR1/P-gp, MRP1 and BCRP and enhance the cytotoxicity of anticancer drugs. Therefore we can use the COX inhibitors to potentialize the effects of chemotherapeutic agents and reverse multidrug resistance to facilitate the patient who may benefit from addition of COX inhibitors to standard cytotoxic therapy.