Hypoxia and Proton microbeam: Role of Gap Junction Intercellular Communication in Inducing Bystander Responses on Human Lung Cancer Cells and Normal Cells

2022 ◽  
Author(s):  
Narongchai Autsavapromporn ◽  
Alisa Kobayashi ◽  
Cuihua Liu ◽  
Churdsak Jaikang ◽  
Tengku Ahbrizal Tengku Ahmad ◽  
...  

Radiation-induced bystander effect (RIBE) has been identified as an important contributing factor to tumor resistance and normal tissue damage. However, the RIBE in cancer and normal cells under hypoxia remain unclear. In this study, confluent A549 cancer and WI-38 normal cells were subjected to condition of hypoxia or normoxia, before exposure to high-LET protons microbeam. After 6 h incubation, cells were harvested and assayed for colony formation, micronucleus formation, chromosome aberration and western blotting. Our results show that there were differences of RIBE in bystander A549 and WI-38 cells under hypoxia and normoxia. The differences were also observed in the roles of HIF-1α expression in bystander A549 and WI-38 cells under both conditions. Furthermore, inhibition of gap junction intercellular communication (GJIC) showed a decrease in toxicity of hypoxia-treated bystander A549 cells, but increased in bystander WI-38 cells. These findings clearly support that GJIC protection of bystander normal cells from toxicity while enhancing in bystander cancer cells. Together, the data show a promising strategy for high-LET radiation in designing an entire new line of drugs, either increase or restore GJIC in bystander cancer cells which in turn leads to enhancement of radiation accuracy for treatment of hypoxic tumors.

Author(s):  
Paiwan BUACHAN ◽  
Maneekarn NAMSA-AID ◽  
Wanlaya TANECHPONGTAMB

Terrein is a fungal metabolite that has already been reported with anticancer properties. However, the effect on the aggressive phenotype of cancer cells has not been elucidated yet.  In the present study, the cytotoxicity of terrein was first determined against lung cancer cells (A549) model and compared with several normal cell lines (Vero, L6, and H9C2 cells). The data demonstrated that terrein had a specific effect on A549 cells relative to normal cells with high selectivity index values. Then, the hypoxic model that recognized to induce aggressive abilities was established in A549 cells by cobalt chloride (CoCl2) stimulation. With this model, terrein could reduce HIF-1α, a marker of hypoxia, and inhibit both migration and invasion of which the effect on invasion is more explicit. Our results demonstrated that terrein has a potential new role as the anti-aggressive phenotype by inhibiting cancer cell migration and invasion through HIF-1α reduction. HIGHLIGHTS Terrein, a secondary bioactive metabolite extracted from Aspergillus terreus, demonstrates anticancer effect on lung cancer cells with less cytotoxic on normal cells CoCl2 treatment was successfully used for creating hypoxic model which resulting in HIF-1a augmentation and aggressive abilities enhancement in lung cancer cells Terrein could reduce HIF-1a expression and invasive ability of lung cancer cells demonstrated the potential role as anti-metastatic agent for lung cancer GRAPHICAL ABSTRACT


Cancers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 368 ◽  
Author(s):  
Sanjeevani Arora ◽  
Joshua Heyza ◽  
Elaine Chalfin ◽  
Randall Ruch ◽  
Steve Patrick

The radiation-induced bystander effect (RIBE) can increase cellular toxicity in a gap junction dependent manner in unirradiated bystander cells. Recent reports have suggested that cisplatin toxicity can also be mediated by functional gap junction intercellular communication (GJIC). In this study using lung and ovarian cancer cell lines, we showed that cisplatin cytotoxicity is mediated by cellular density. This effect is ablated when GJA1 or Connexin 43 (Cx43) is targeted, a gap junction gene and protein, respectively, leading to cisplatin resistance but only at high or gap junction forming density. We also observed that the cisplatin-mediated bystander effect was elicited as DNA Double Strand Breaks (DSBs) with positive H2AX Ser139 phosphorylation (γH2AX) formation, an indicator of DNA DSBs. These DSBs are not observed when gap junction formation is prevented. We next showed that cisplatin is not the “death” signal traversing the gap junctions by utilizing the cisplatin-GG intrastrand adduct specific antibody. Finally, we also showed that cells deficient in the structure-specific DNA endonuclease ERCC1-ERCC4 (ERCC1-XPF), an important mediator of cisplatin resistance, further sensitized when treated with cisplatin in the presence of gap junction forming density. Taken together, these results demonstrate the positive effect of GJIC on increasing cisplatin cytotoxicity.


2001 ◽  
Vol 280 (2) ◽  
pp. L191-L202 ◽  
Author(s):  
Yihe Guo ◽  
Cara Martinez-Williams ◽  
Clare E. Yellowley ◽  
Henry J. Donahue ◽  
D. Eugene Rannels

Extracellular matrix (ECM) proteins promote attachment, spreading, and differentiation of cultured alveolar type II epithelial cells. The present studies address the hypothesis that the ECM also regulates expression and function of gap junction proteins, connexins, in this cell population. Expression of cellular fibronectin and connexin (Cx) 43 increase in parallel during early type II cell culture as Cx26 expression declines. Gap junction intercellular communication is established over the same interval. Cells plated on a preformed, type II cell-derived, fibronectin-rich ECM demonstrate accelerated formation of gap junction plaques and elevated gap junction intercellular communication. These effects are blocked by antibodies against fibronectin, which cause redistribution of Cx43 protein from the plasma membrane to the cytoplasm. Conversely, cells cultured on a laminin-rich ECM, Matrigel, express low levels of Cx43 but high levels of Cx26, reflecting both transcriptional and translational regulation. Cx26 and Cx43 thus demonstrate reciprocal regulation by ECM constituents.


2015 ◽  
Vol 34 (4) ◽  
pp. 2133-2141 ◽  
Author(s):  
LINGZHI WANG ◽  
JIANXIN PENG ◽  
HUANSEN HUANG ◽  
QIN WANG ◽  
MEILING YU ◽  
...  

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