Role of chronic obstructive pulmonary disease in lung cancer pathogenesis

Table 3 Signalling pathways common to chronic obstructive pulmonary disease and lung cancer

Signal pathway	Downstream effects	Role in COPD	Role in lung cancer	Ref.
NFκβ	↑MMPs, ↑TNFα, ↓apoptosis, ↑angiogenesis	↑inflammation	↑cell proliferation, ↓cell death, metastasis	[111]
PI3K	Activation and migration of leukocytes	↑inflammation	↑cell proliferation, ↓cell death	[112,113]
P38 MAPK	Block JNK/c-Jun, ↑TNFα	↑inflammation	Metastasis, ↓cell death	[114]
PPARγ	↓MMP9, ↓TNFα, ↓TGFβ	↓inflammation	↑cell differentiation, ↓cell proliferation	[115,116]

COPD: Chronic obstructive pulmonary disease; MMPs: Matrix-metalloproteinases; JNK: c-Jun N-terminal kinases; TNFα: Tumour necrosis factor alpha; TGFβ: Tissue growth factor beta.