Nowadays adenocarcinoma,one subtype of lung cancers, is the most common histologic type,which always appears as localized GGOs on CT, and a pure ground glass nodule is likely a preinvasive lesion [19]. Although there are several types of pGGNs, all of which are slow-progressing diseases, but they can show differing growth patterns and degrees of invasion, such as adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and even invasive adenocarcinoma (IAC)[20].IF the pGGN is AIS or MIA, a small wide wedge dissection would be enough without lymph node, but a small peripheral IAC need segmentectomy, which may be more suitable [5].So it is crucial to elucidate the effective diagnostic markers of pGGN.
Our study used the GEO database to download mRNA expression profile GSE193725 and then perform a WGCNA on it. Using the novel approach, all 4475 DEGs were obtained by the ‘limma’ on SangerBox network,all these DEGs were then clustered into seven modules. And the black module,which included 590 genes,was chosen to be the most upregulated module closely related to the pGGN(whose correlation score is 0.66,and p < 0.0001). All of these identified genes were enriched in ‘Lysosome,’ ‘Ribosome,’ and ‘metabolic pathways’ mainly. GSEA showed that ‘VASCULAR_SMOOTH_MUSCLE_CONTRACTION’ was markedly in the pGGN group. Six overlapped hub genes, CCT3, RPL4, RPL8, RPLP0, RPS16, RPS2, were identified by cytoscape software. And we found the identified hub genes CCT3 and RPL8 demonstrated a powerful discrimination capability as potential biomarkers for pGGN.
using mRNA as a template, and using amino acids as raw materials to synthesize proteins is the ribosome's primary function [21]. Previous studies have showed that the ribosome has a great deal of functions, including affecting protein synthesis and taking a significant role in cell differentiation, proliferation,transformation and apoptosis [22]. The ribosome biogenesis dysregulation was important in cancer because it identifies nucleoli with irregular shapes and numbers [23]. And ribosome biogenesis hyperactivation addiction in cancer cells is clear, by illustrating its numerous molecules as cancer treatments through impairing ribosome production[24].In normal cells,ribosomes are involved in proliferating by synthesizing proteins, but in cancer cells,ribosomes are needed according to metabolic requirements. And what’s more, previous study has reported that cancer cells express about nearly 10,000 different proteins[25]. Ribosome biogenesis can be a target in cancer cells because of three main reasons,firstly in certain cancer types and its cell populations,this process is highly active and essential,secondly several chemotherapy drugs have been already proven to exert their some pharmacological effects partly,through impairing ribosome biogenesis, and last but not the least blocking ribosome biogenesis can lead in a lot of cases to the activation of p53 [26].
RPL4 could be bound by PRDX2, being reduced the interaction between MDM2, resulting in promoting the proliferation of colorectal cancer cells [27].RPL8 is reported that with pancreatic tumor grades it alters significantly, which may predict a differential expression prognosis of pancreatic cancer[28]. RPLP0 suppressed by the upregulated level of miR-4731-5p, can be a target in non-small-cell lung cancer [29]. And for advanced hepatocellular carcinoma cells,RPS16 may be a potential novel target[30].PRS2 identified by hub genes was lowly expressed in rats with pulmonary arterial hypertension [31]. To sum up, RPL4, RPL8, RPLP0, RPS16, RPS2 and CCT3, have the powerful ability to screen out pGGN from the controls. And CCT3 and RPL8 demonstrated a powerful discrimination capability as potential biomarkers for pGGN. But it is still required that more sample size is needed to validate the efficacy of these overlapped genes as biomarkers for pGGN in the immediate future.