Cyclooxygenase-2 in Lung Carcinogenesis and Chemoprevention

The potential role of renin angiotensin system in acute leukemia: a narrative review

Acute leukemias (ALs) are the most common cancers in pediatric population. There are two types of ALs: acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Some studies suggest that the Renin Angiotensin System (RAS) has a role in ALs. RAS signaling modulates, directly and indirectly, cellular activity in different cancers, affecting tumor cells and angiogenesis. Our review aimed to summarize the role of RAS in ALs and to explore future perspectives for the treatment of these hematological malignancies by modulating RAS molecules. The database including Pubmed, Scopus, Cochrane Library, and Scielo were searched to find articles about RAS molecules in ALL and in pediatric patients. The search terms were "RAS", "Acute Leukemia", "ALL", "Angiotensin-(1-7)", "Pediatric", "Cancer", "Angiotensin II", "AML". In the bone marrow, RAS has been found to play a key role in blood cell formation, affecting several processes including apoptosis, cell proliferation, mobilization, intracellular signaling, angiogenesis, fibrosis, and inflammation. Local tissue RAS modulates tumor growth and metastasis through autocrine and paracrine actions. RAS mainly acts via two molecules, Angiotensin II (Ang II) and Angiotensin (1-7) [Ang-(1-7)]. While Ang II promotes tumor cell growth and stimulates angiogenesis, Ang-(1-7) inhibits the proliferation of neoplastic cells and the angiogenesis, suggesting a potential therapeutic role of this molecule in ALL. The interaction between ALs and RAS reveals a complex network of molecules that can affect the hematopoiesis and the development of hematological cancers. Understanding these interactions could pave the way for innovative therapeutic approaches targeting RAS components.

Lipoxins exert antiangiogenic and anti-inflammatory effects on Kaposi's sarcoma cells

Lipoxin A4 (LXA4) is an endogenously produced host molecule with anti-inflammatory resolution effects. Previous studies demonstrated it to be involved in anti-vascular endothelial growth factor (VEGF)-mediated angiogenesis and in a possible anticancer role via interaction with its receptor, lipoxin A 4 receptor (ALXR). Here, we examined the effects of LXA4 and its epimer 15-epi-LXA4 in inhibiting proinflammatory and angiogenic functions in a human Kaposi's sarcoma tumor-derived cell line (KS-IMM). KS-IMM cells expressed increased levels of inflammatory cyclooxygenase 2 (COX-2) and 5-lipoxygenase (5-LO) pathway enzymes when compared with human microvascular dermal endothelial cells (HMVEC-d). KS-IMM cells secreted high levels of prostaglandin E2 (PGE2) and chemotactic leukotriene B4 (LTB4). Treatment with LXA4 or 15-epi-LXA4 effectively reduced the levels of COX-2, 5-LO proteins, and secretion of PGE2 and LTB4 in KS-IMM cells. LXA4 or 15-epi-LXA4 treatment also decreased secretion of proinflammatory interleukin 6 (IL-6) and IL-8 cytokines but induced the secretion of anti-inflammatory IL-10. LXA4 treatment reduced the phosphorylation of VEGF receptor (VEGFR) and ephrin family receptor tyrosine kinases. LXA4 treatment effectively induced dephosphorylation of multiple cellular kinases such as Focal Adhesion Kinase, Protein kinase B, nuclear factor kappa-light-chain-enhancer of activated B cells, and Extracellular signal-regulated kinases (ERK)1/2, and reduced angiogenic factor VEGF-C secretion in KS cells. LX treatment drastically induced the Src-homology 2 domain-containing phosphatase tyrosine (Y542) phosphatase and reduced VEGFR-2 phosphorylation at sites Y1059, Y1175, and Y1212. Treatment of KS-IMM cells with LXA4 resulted in selective localization of VEGFR-2 in nonlipid raft (non-LR) and ALXR to LR fractions. These results demonstrated that LXA4 or 15-epi-LXA4 induce anti-inflammatory and antiangiogenic effects in KS cells and suggest that treatment with LXs is an attractive novel strategy against KS.

COX-2 is overexpressed in primary prostate cancer with metastatic potential and may predict survival. A comparison study between COX-2, TGF-beta, IL-10 and Ki67

BACKGROUND

The immune modulating molecules cyclooxygenase-2 (COX-2), transforming growth factor-beta (TGF-beta) and interleukin-10 (IL-10) have regulatory roles in cancer progression. There are conflicting data regarding the roles of these molecules in prostate cancer. To elucidate the prognostic impact of these proteins and provide information on prognosis and treatment, we compared the expression of COX-2, TGF-beta, and IL-10 in prostate cancer specimens with or without metastases. Ki67 was included as a measure of growth fraction of tumor cells.

METHODS

Digital video analysis images from tumor cell areas and tumor stromal areas were analyzed on formalin fixed, paraffin-embedded and immunohistochemical stained cancer specimens from 59 patients: 32 patients with metastases and 27 patients without clinical, biochemical, or radiological evidence of metastases within 10 years after diagnosis. The expression of COX-2 was scored as negative, weak, moderate, or strong. The expressions of TGF-beta and IL-10 were assessed as proportions of moderately or strongly stained cells. Ki67 was detected as strong nuclear staining in proliferating cells.

RESULTS

In primary cancers in the metastatic group, COX-2, TGF-beta and Ki67 were stronger expressed in epithelial tumor cell and tumor stromal areas compared with non-metastatic cancers (for all markers, p<0.0001). High intensity of COX-2 staining in tumor areas was strongly associated with death from prostate cancer in univariate analyses (hazard ratio [HR] 95% CI, 4.0 (1.1-14.5)). In multivariate analyses, the risk estimate was strengthened but did not reach significance. No associations to death were found for the other markers.

CONCLUSION

High expression of COX-2, TGF-beta and Ki67 were in metastatic primary prostate carcinoma compared to non-metastatic cancers. High expression of COX-2 was associated to death from prostate carcinoma.

Use of nonaspirin NSAIDs and risk of lung cancer

Epidemiologic evidence is conflicting regarding the potential for nonsteroidal antiinflammatory drugs (NSAIDs) to lower the risk of lung cancer. We thus determined the incidence of lung cancer among a cohort of over 242,000 adults in Denmark who had been issued NSAID prescriptions during 1991-2002 and calculated the relative risks of this cancer according to the numbers of prescriptions received. Similar analyses were conducted among a subset with chronic obstructive pulmonary disease, of whom the large majority was assumed to have been smokers, as an indirect control for smoking. Utilization of Danish registries ensured essentially complete and unbiased ascertainment of prescriptions and cancer outcomes. The relative risks of lung cancer among NSAID users redeeming 10 or more prescriptions vs. nonusers in the general population and among chronic obstructive pulmonary disease patients were 1.51 (95% CI = 1.33-1.71) and 1.55 (95% CI = 0.93-2.60) and tended to decline with decreasing numbers of NSAIDs prescribed. Separate analyses for adenocarcinoma and squamous cell carcinoma also failed to show reduced risks among NSAID users. Confounding by indication may have contributed to the increased risks, but the study provides no evidence to suggest that recent NSAID intake may be protective for lung cancer.