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G1 Switch 2 regulates a G1-lipid checkpoint dependent radiation sensitivity of human head and neck squamous cell carcinoma
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A. Newman / Free Radical Biology and Medicine 128 (2018) S61–S78
response in cancer progression. In the present work, using mouse B-cell lymphoma tumor model, we report that HSF-1 ablation ( þ/- or -/-) of hosts enhances pro-inflammatory response by altering macrophage phenotypes at tumor site, and it inhibits lymphoma tumor xenograft growth. Even though high abundance of tumor-associated macrophages (TAMs) and increased CCl2 in peripheral circulation were found in HSF-1 -/- hosts, CD31 þ expression was low in these tumors indicating reduced angiogenesis. Furthermore, in HSF-1 -/mice grown tumors, TAMs showed very low CD206 þ mannose receptor (MR), which is a hallmark of alternatively activated macrophages (M2) phenotype, expression suggesting that TAMs, present in HSF-1-/- hosts tumor microenvironment, exhibit pro-inflammatory M1 phenotype. Also, an increased plasma level IL-6 and IgA, higher cytotoxic CD8 þ T cells in spleenocytes, and higher IFN-g were observed in tumor bearing HSF-1 -/- mice. Our in-vitro assay indicated that addition of HSF-1 -/- sera induced caspase-independent lymphoma tumor cell death (involving a distinct 55kD PARP-1 catalytic domain cleavage and 75kD fragment in TOPO I) and increased lysosomal enzyme activity, as measured by CD40L in tumor bearing HSF-1-/mice plasma. Taken together, our results establish that HSF-1 is a critical determinant in TAM polarization and tumor immunity, and its repression could enhance innate immunity and immune surveillance against lymphoma tumor growth. Therefore, HSF-1 is a major determinant in TAM polarization, and it is a potential target for lymphoma treatment.
https://doi.org/10.1016/j.freeradbiomed.2018.10.141
138
Reactive oxygen species derived from mitochondria increase non-heme iron incorporation in gastric cancer cells by regulating the expression of transporters Hiromu Ito 1,*, Hiromi Kurokawa 2, Aki Hirayama 3, Hiroko Indo 1, Hideyuki Majima 1, Hirofumi Matsui 2 1
Kagoshima University, Japan University of Tsukuba, Japan 3 Tsukuba University of Technology, Japan 2
Iron is an essential substance for human and play many important roles such as transportation of oxygen and synthesis of DNA. However, the concentration of iron in body is strictly regulated because excess iron causes reactive oxygen species (ROS) and damages cells. Most of iron in body classified as follows: heme iron and non-heme iron. We previously reported that high level ROS derived from mitochondria (mitROS) in cancer cells enhanced the expression of heme iron transporter. In this study, we examined the relationship between non-heme iron transportation and mitROS. We used a rat gastric normal, cancer and manganese superoxide dismutase (MnSOD)-overexpressing cancer cell line, in which mitROS are specifically scavenged. Among these cell lines, non-heme iron incorporation was compared using radioactive iron compound. The incorporation in cancer cells was greater than in normal cells and decreased by overexpressing MnSOD. We also studied the expression of transporters which was related to incorporation and excretion of non-heme iron. The expression of incorporation protein DMT1 in cancer cells was greater than in normal and MnSOD-overexpressing cancer cells. On the other hand, excretion protein ferroportin decreased in cancer compared to MnSODoverexpressing cancer cells. Thus, we concluded that cancer cellular ROS from mitochondria regulated the incorporation and excretion of nonheme iron via expression of iron transport protein.
https://doi.org/10.1016/j.freeradbiomed.2018.10.142
139
G0/G1 Switch 2 regulates a G1-lipid checkpoint dependent radiation sensitivity of human head and neck squamous cell carcinoma Amanda Kalen*, Ehab Sarsour, Wafa Asha, Jyung Son, Prabhat Goswami The University of Iowa, USA
A recent study reports the presence of a G1-lipid checkpoint that is dysregulated in clear cell renal carcinoma. A defective G1-lipid checkpoint forces these cells to utilize lipids as their energy source. Head and neck squamous cell carcinoma (HNSCC) cells with a higher percentage of G0/G1 cells (low proliferative index, LPI) are more resistant to radiation therapy compared to HNSCC cells with a lower percentage of G0/G1 cells (high proliferative index, HPI)2. In this study, we investigated whether lipid metabolism regulates HNSCC cell cycle phase specific radiation sensitivity. Results from Fluorescent Ubiquitination-based Cell Cycle Indicator expressing Cal27 cells showed that cells in G0/G1 phase (LPI) are more resistant to radiation therapy compared to cells in S/G2/M phases (HPI). RNAseq and bioinformatics identified lipid and mitochondrial metabolism as the major intrinsic pathways that are different between HPI and LPI Cal27 cultures. Among the genes regulating lipid metabolism, mRNA levels of G0/G1 Switch 2 (G0S2) were found to be significantly higher in LPI compared to HPI Cal27 cultures. G0S2 was originally identified in blood mononuclear cells as a cell cycle protein of unknown functions3. Recent literature reports G0S2 as a negative regulator of the cytoplasmic neutral lipase, adipose triglyceride lipase (ATGL)4. siG0S2 treatment of Cal27 LPI cultures recruited more cells into the proliferative cycle enhancing their radiation sensitivity. In contrast, inhibition of ATGL activity with atglistatin suppressed radiation induced toxicity. Furthermore, LPI cultures treated with palmitate enhanced mitochondrial respiration and increased ROS levels as well as lipid peroxidation resulting in radiation sensitization. These results support the hypothesis that G0S2 coordinates a G1-lipid checkpoint: G0/G1 cells prior to this checkpoint are resistant to radiation treatment, whereas S/G2/M cells that are beyond this checkpoint are radiation sensitive. We propose palmitate as a newly identified radiation sensitizer for HNSCC. (PMID:27956548; PMID:25229973; PMID:1930693; PMID:20676045).
https://doi.org/10.1016/j.freeradbiomed.2018.10.143
140
Increased expression and activity of Sod2 promotes transcoelomic metastasis in ovarian cancer Yeon Kim 1,*, Piyushi Gupta Vallur 1, Victoria Jones 2, Dong-Hui Shin 1, Beth Worley 1, Rebecca Phaeton 1, Mythreye Karthikeyan 3, Nadine Hempel 1 1
Penn State University, USA Penn State Hershey Medical Center, USA 3 University of South Carolina, USA 2
Ovarian cancer is the leading cause of death from gynecologic malignancy due to asymptomatic progression of the disease to advanced stages. Patients with widespread metastases are characterized by a large volume of ascites in the peritoneal cavity within which floating cancer cell populations are found in malignant cases. Metastasis of ovarian cancer occurs when cancer cells escape the primary tumor and adapt to survive under stress conditions
A. Newman / Free Radical Biology and Medicine 128 (2018) S61–S78
response in cancer progression. In the present work, using mouse B-cell lymphoma tumor model, we report that HSF-1 ablation ( þ/- or -/-) of hosts enhances pro-inflammatory response by altering macrophage phenotypes at tumor site, and it inhibits lymphoma tumor xenograft growth. Even though high abundance of tumor-associated macrophages (TAMs) and increased CCl2 in peripheral circulation were found in HSF-1 -/- hosts, CD31 þ expression was low in these tumors indicating reduced angiogenesis. Furthermore, in HSF-1 -/mice grown tumors, TAMs showed very low CD206 þ mannose receptor (MR), which is a hallmark of alternatively activated macrophages (M2) phenotype, expression suggesting that TAMs, present in HSF-1-/- hosts tumor microenvironment, exhibit pro-inflammatory M1 phenotype. Also, an increased plasma level IL-6 and IgA, higher cytotoxic CD8 þ T cells in spleenocytes, and higher IFN-g were observed in tumor bearing HSF-1 -/- mice. Our in-vitro assay indicated that addition of HSF-1 -/- sera induced caspase-independent lymphoma tumor cell death (involving a distinct 55kD PARP-1 catalytic domain cleavage and 75kD fragment in TOPO I) and increased lysosomal enzyme activity, as measured by CD40L in tumor bearing HSF-1-/mice plasma. Taken together, our results establish that HSF-1 is a critical determinant in TAM polarization and tumor immunity, and its repression could enhance innate immunity and immune surveillance against lymphoma tumor growth. Therefore, HSF-1 is a major determinant in TAM polarization, and it is a potential target for lymphoma treatment.
https://doi.org/10.1016/j.freeradbiomed.2018.10.141
138
Reactive oxygen species derived from mitochondria increase non-heme iron incorporation in gastric cancer cells by regulating the expression of transporters Hiromu Ito 1,*, Hiromi Kurokawa 2, Aki Hirayama 3, Hiroko Indo 1, Hideyuki Majima 1, Hirofumi Matsui 2 1
Kagoshima University, Japan University of Tsukuba, Japan 3 Tsukuba University of Technology, Japan 2
Iron is an essential substance for human and play many important roles such as transportation of oxygen and synthesis of DNA. However, the concentration of iron in body is strictly regulated because excess iron causes reactive oxygen species (ROS) and damages cells. Most of iron in body classified as follows: heme iron and non-heme iron. We previously reported that high level ROS derived from mitochondria (mitROS) in cancer cells enhanced the expression of heme iron transporter. In this study, we examined the relationship between non-heme iron transportation and mitROS. We used a rat gastric normal, cancer and manganese superoxide dismutase (MnSOD)-overexpressing cancer cell line, in which mitROS are specifically scavenged. Among these cell lines, non-heme iron incorporation was compared using radioactive iron compound. The incorporation in cancer cells was greater than in normal cells and decreased by overexpressing MnSOD. We also studied the expression of transporters which was related to incorporation and excretion of non-heme iron. The expression of incorporation protein DMT1 in cancer cells was greater than in normal and MnSOD-overexpressing cancer cells. On the other hand, excretion protein ferroportin decreased in cancer compared to MnSODoverexpressing cancer cells. Thus, we concluded that cancer cellular ROS from mitochondria regulated the incorporation and excretion of nonheme iron via expression of iron transport protein.
https://doi.org/10.1016/j.freeradbiomed.2018.10.142
139
G0/G1 Switch 2 regulates a G1-lipid checkpoint dependent radiation sensitivity of human head and neck squamous cell carcinoma Amanda Kalen*, Ehab Sarsour, Wafa Asha, Jyung Son, Prabhat Goswami The University of Iowa, USA
A recent study reports the presence of a G1-lipid checkpoint that is dysregulated in clear cell renal carcinoma. A defective G1-lipid checkpoint forces these cells to utilize lipids as their energy source. Head and neck squamous cell carcinoma (HNSCC) cells with a higher percentage of G0/G1 cells (low proliferative index, LPI) are more resistant to radiation therapy compared to HNSCC cells with a lower percentage of G0/G1 cells (high proliferative index, HPI)2. In this study, we investigated whether lipid metabolism regulates HNSCC cell cycle phase specific radiation sensitivity. Results from Fluorescent Ubiquitination-based Cell Cycle Indicator expressing Cal27 cells showed that cells in G0/G1 phase (LPI) are more resistant to radiation therapy compared to cells in S/G2/M phases (HPI). RNAseq and bioinformatics identified lipid and mitochondrial metabolism as the major intrinsic pathways that are different between HPI and LPI Cal27 cultures. Among the genes regulating lipid metabolism, mRNA levels of G0/G1 Switch 2 (G0S2) were found to be significantly higher in LPI compared to HPI Cal27 cultures. G0S2 was originally identified in blood mononuclear cells as a cell cycle protein of unknown functions3. Recent literature reports G0S2 as a negative regulator of the cytoplasmic neutral lipase, adipose triglyceride lipase (ATGL)4. siG0S2 treatment of Cal27 LPI cultures recruited more cells into the proliferative cycle enhancing their radiation sensitivity. In contrast, inhibition of ATGL activity with atglistatin suppressed radiation induced toxicity. Furthermore, LPI cultures treated with palmitate enhanced mitochondrial respiration and increased ROS levels as well as lipid peroxidation resulting in radiation sensitization. These results support the hypothesis that G0S2 coordinates a G1-lipid checkpoint: G0/G1 cells prior to this checkpoint are resistant to radiation treatment, whereas S/G2/M cells that are beyond this checkpoint are radiation sensitive. We propose palmitate as a newly identified radiation sensitizer for HNSCC. (PMID:27956548; PMID:25229973; PMID:1930693; PMID:20676045).
https://doi.org/10.1016/j.freeradbiomed.2018.10.143
140
Increased expression and activity of Sod2 promotes transcoelomic metastasis in ovarian cancer Yeon Kim 1,*, Piyushi Gupta Vallur 1, Victoria Jones 2, Dong-Hui Shin 1, Beth Worley 1, Rebecca Phaeton 1, Mythreye Karthikeyan 3, Nadine Hempel 1 1
Penn State University, USA Penn State Hershey Medical Center, USA 3 University of South Carolina, USA 2
Ovarian cancer is the leading cause of death from gynecologic malignancy due to asymptomatic progression of the disease to advanced stages. Patients with widespread metastases are characterized by a large volume of ascites in the peritoneal cavity within which floating cancer cell populations are found in malignant cases. Metastasis of ovarian cancer occurs when cancer cells escape the primary tumor and adapt to survive under stress conditions