Human Lung Microbiome on the Way to Cancer.

Olga V Kovaleva,Alexei Gratchev,Mikhail M Davydov,Murat S Shogenov,Daniil Romashin,Irina B Zborovskaya

doi:10.1155/2019/1394191

Olga V Kovaleva, Alexei Gratchev + Show 4 more

Open Access

https://doi.org/10.1155/2019/1394191

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Abstract

Recent research on cancer-associated microbial communities led to the accumulation of data on the interplay between bacteria, immune and tumor cells, the pathways of bacterial induction of carcinogenesis, and its meaningfulness for medicine. Microbial communities that have any kind of impact on tumor progression and microorganisms associated with tumors have been defined as oncobiome. Over the last decades, a number of studies were dedicated to Helicobacter pylori and its role in the progression of stomach tumors, so this correlation can be regarded as proven. Involvement of bacteria in the induction of lung cancer has been largely ignored for a long time, though some correlations between this type of cancer and lung microbiome were established. Despite the fact that in the present the microbial impact on lung cancer progression has many confirmations, the underlying mechanisms are poorly understood. Microorganisms can contribute to tumor initiation and progression through production of bacteriotoxins and other proinflammatory factors. The purpose of this review is to organize the available data on lung cancer microbiome and its role in malignant tumor progression.

Highlights

A vast amount of highly diverse microorganisms inhabits the human organism
The smaller number of studies is dedicated to the investigation of lung microbiome, since the lung was supposed to be sterile for a long time due to the difficulties in cultivation of lung-specific microorganisms [2]
Capnocytophaga, Selenomonas, Veillonella, and Neisseria genera can be highlighted inter alia of potential lung cancer biomarkers. Increasing titer of these microorganisms correlates with both small-cell carcinoma (SCC) and adenocarcinoma (AC)

Summary

Introduction

A vast amount of highly diverse microorganisms inhabits the human organism. Microorganisms are present in all mucous membranes and participate in various physiological processes. It is traditionally believed that human microbiome most strongly affects intestinal, skin, and mucous membranes. The smaller number of studies is dedicated to the investigation of lung microbiome, since the lung was supposed to be sterile for a long time due to the difficulties in cultivation of lung-specific microorganisms [2]. With the development of methods that do not require microorganism cultivation, a number of researches have demonstrated that there is a unique microbial community that inhabits the lungs [3]. A lung mucous membrane has its own resident microbiome [4]. There are three existing key factors defining healthy lung microbiome: migration of microorganisms down from the upper airways, disposal of microorganisms by human organism, and local growth conditions [5]

Normal Lung Microbiome

Lung Microbiome in Nononcology Disease

Lung Cancer Microbiome

Microbiome and Lung Cancer

Conclusions

Conflicts of Interest