554 Cyclin D1 ribozyme inhibits the proliferation of urethane induced lung cancer cells containing activated K-ras

Tetracenomycin X (Tcm X) has been reported to have antitumour activity in various cancers, but there have not been any studies on its activity with respect to lung cancer to date. Therefore, this study aims to investigate the anti-lung cancer activity of Tcm X. In this study, we found that tetracenomycin X showed antitumour activity in vivo and selectively inhibited the proliferation of lung cancer cells without influencing lung fibroblasts. In addition, apoptosis and autophagy did not contribute to the antitumour activity. Tetracenomycin X exerts antitumour activity through cell cycle arrest induced by the downregulation of cyclin D1. To explore the specific mechanism, we found that tetracenomycin X directly induced cyclin D1 proteasomal degradation and indirectly downregulated cyclin D1 via the activation of p38 and c-JUN proteins. All these findings were explored for the first time, which indicated that tetracenomycin X may be a powerful antimitotic class of anticancer drug candidates for the treatment of lung cancer in the future.

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Application of TEM: Dynamic changes of AKAP95-Cx43 complex during G1 phase of lung cancer cells

10.21203/rs.3.rs-66232/v1 ◽

2020 ◽

Author(s):

Zifeng Deng ◽

Rong Liu ◽

Huiling Guo ◽

Luming Yao ◽

FengKai Ruan ◽

...

Keyword(s):

Lung Cancer ◽

Cyclin D1 ◽

Cancer Cells ◽

Connexin 43 ◽

Laser Scanning Microscopy ◽

Lung Cancer Cells ◽

G1 Phase ◽

Nuclear Pore ◽

Dynamic Changes ◽

Cyclin E1

Abstract BackgroundAKAP95(A-kinase anchoring protein) and Cx43 (connexin 43) express abnormally in lung cancer cells. As potential tumor therapeutic targets, specific process of bindings and dynamic changes of Cx43-AKAP95 complex in lung cancer cells may guide further treatments and detections of lung cancer. However, the process remains unclear now. We are aiming at investigating the dynamic changes of expression, localization, and binding of AKAP95 and Cx43, as well as their interaction with cyclin D1 and cyclin E1 in lung cancer cells during G1 phase.MethodsA549 and Beas-2B cells were arrested at preliminary stage(P), middle stage(M) and restriction point(R) of G1 phase and Western blot(WB), Confocal laser scanning microscopy (CLSM) and Transmission electron microscope (TEM) were used in our study to detect proteins to provide further evidence of the correlation of these proteins.Results: 1) AKAP95 carries Cx43 into the nucleus through the nuclear pore by binding to it during G1 phase. Some AKAP95 and Cx43 can aggregate and form larger protein aggregates. The process happens mainly during R stage. 2) AKAP95 and Cx43 mainly bind to cyclin D1 during P and M stage while bind to cyclin E1 during R stage respectively. Complexes of AKAP95-cyclin D1 and Cx43-cyclin D1 cannot enter nucleus while AKAP95-cyclin E1 and Cx43-cyclin E1 can.Conclusions1) Binding process of AKAP95-Cx43 complexes/ aggregates can be summarize as ‘bind and aggregate -target and enter nucleus- keep binding/aggregating in nucleus’. 2) Cyclin E1 was involved in the binding/aggregation and nuclear entry of AKAP95 and Cx43 while cyclin D1 only binds to them respectively in the cytoplasm.

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Abrogation of cyclin D1 expression predisposes lung cancer cells to serum deprivation-induced apoptosis

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1999.276.4.l679 ◽

1999 ◽

Vol 276 (4) ◽

pp. L679-L687 ◽

Cited By ~ 2

Author(s):

Barbara Driscoll ◽

Susan Buckley ◽

Lora Barsky ◽

Kenneth Weinberg ◽

Kathryn D. Anderson ◽

...

Keyword(s):

Lung Cancer ◽

Growth Factor ◽

Cyclin D1 ◽

Cancer Cells ◽

Chromatin Condensation ◽

Serum Deprivation ◽

Single Strand ◽

Lung Cancer Cells ◽

Nuclear Antigen ◽

Dna Breaks

Cyclin D1 antisense (D1AS)-transfected lung epithelial cell lines were serum deprived and then analyzed for three hallmarks of apoptosis: appearance of single-strand DNA breaks, alteration of apoptosis-related protein expression, and induction of chromatin condensation. Single-strand DNA breaks appeared at significant levels 24 h after serum deprivation, whereas induction of chromatin condensation was observed after 72 h. The antioxidants dimethyl sulfoxide, ascorbate, and glutathione, as well as insulin-like growth factor-I, inhibited induction of DNA damage in this assay. Additionally, proliferating cell nuclear antigen expression is completely suppressed in the D1AS cells, indicating a mechanism to explain the reduced capacity for DNA repair. Increased expression of cyclin D1, which is a common lesion in lung cancer, may thus prevent induction of apoptosis in an oxidizing and growth factor-poor environment. Reducing cyclin D1 expression in lung cancer cells by expression of D1AS RNA disrupted these protective pathways.

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Gambogenic acid induces G1 arrest via GSK3β-dependent cyclin D1 degradation and triggers autophagy in lung cancer cells

Cancer Letters ◽

10.1016/j.canlet.2012.03.004 ◽

2012 ◽

Vol 322 (2) ◽

pp. 185-194 ◽

Cited By ~ 47

Author(s):

Xian-Jun Yu ◽

Quan-Bin Han ◽

Zhe-Sheng Wen ◽

Liang Ma ◽

Jin Gao ◽

...

Keyword(s):

Lung Cancer ◽

Cyclin D1 ◽

Cancer Cells ◽

Lung Cancer Cells ◽

G1 Arrest

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AKAP95 transports Cx43 into nucleus, regulating G1/S transition of A549 cells.

10.21203/rs.3.rs-85419/v1 ◽

2020 ◽

Author(s):

Zifeng Deng ◽

Rong Liu ◽

Huiling Guo ◽

Luming Yao ◽

FengKai Ruan ◽

...

Keyword(s):

Lung Cancer ◽

Cyclin D1 ◽

Cancer Cells ◽

Nuclear Transport ◽

Laser Scanning Microscopy ◽

Lung Cancer Cells ◽

G1 Phase ◽

Nuclear Localization Sequence ◽

Nuclear Pore ◽

Cyclin E1

Abstract Purpose: Cx43 (connexin 43) has been found to inhibit cell cycle of tumor cells. No nuclear localization sequence of Cx43 was found but the protein has been found in nucleus. The process remains unclear. We are aiming at providing the model that AKAP95 (A-kinase anchoring protein) binds to and transports Cx43 into nucleus of lung cancer cells.Methods: Lung cancer cells were arrested at preliminary stage (P), middle and late stage (M) of G1 phase and restriction point (R). Immunocoprecipitation (Co-IP) and Western blot (WB) were used to analyze expression and binding of AKAP95, Cx43, cyclin D1 and cyclin E1 at different stages of lung cancer cells during G1 phase. Confocal laser scanning microscopy (CLSM) was used to detect the location of proteins in arrested cells. Transmission electron microscope (TEM) with higher resolution was used to detect binding/aggregating and location of the above four proteins at subcellular level.Results: 1) AKAP95 transports Cx43 into the nucleus through the nuclear pore mainly at R stage. Some AKAP95 and Cx43 form protein aggregates during the process. 2) Cyclin E1 was found to be bind/aggregate with AKAP95-Cx43 complex and involved in the nuclear transport of Cx43 mainly at R stage. 3)Cyclin D1 was found to bind with AKAP95 and Cx43 respectively but not to be involved in their aggregating and nuclear transport of Cx43.Conclusions: 1) AKAP95 and Cx43 bind/aggregate to each other during G1 phase, forming AKAP95-Cx43 complexes/aggregates. After their binding/aggregating, AKAP95 targets nuclear pore and matrix, transporting Cx43 into nucleus. Formed AKAP95-Cx43 complexes/ aggregates do not dissociate in nucleus. The process can be summarized as ‘forming AKAP95-Cx43 complexes/aggregates; transporting Cx43 into nucleus; functioning remaining binding/aggregating’. 2) Cyclin D1 was only found to bind to AKAP95 and Cx43 respectively and function in cytoplasm while cyclin E1 was involved in the binding/aggregation of AKAP95 and Cx43, as well as the nuclear transport of Cx43.

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