Possible Oncogenic Viruses Associated with Lung Cancer

The implication of microbiome in lungs cancer: mechanisms and strategies of cancer growth, diagnosis and therapy

Available evidence illustrates that microbiome is a promising target for the study of growth, diagnosis and therapy of various types of cancer. Lung cancer is a leading cause of cancer death worldwide. The relationship of microbiota and their products with diverse pathologic conditions has been getting large attention. The novel research suggests that the microbiome plays an important role in the growth and progression of lung cancer. The lung microbiome plays a crucial role in maintaining mucosal immunity and synchronizing the stability between tolerance and inflammation. Alteration in microbiome is identified as a critical player in the progression of lung cancer and negatively impacts the patient. Studies suggest that healthy microbiome is essential for effective therapy. Various clinical trials and research are focusing on enhancing the treatment efficacy by altering the microbiome. The regulation of microbiota will provide innovative and promising treatment strategies for the maintenance of host homeostasis and the prevention of lung cancer in lung cancer patients. In the current review article, we presented the latest progress about the involvement of microbiome in the growth and diagnosis of lung cancer. Furthermore, we also assessed the therapeutic status of the microbiome for the management and treatment of lung cancer.

Host Transcriptional Regulatory Genes and Microbiome Networks Crosstalk through Immune Receptors Establishing Normal and Tumor Multiomics Metafirm of the Oral-Gut-Lung Axis

The microbiome has shown a correlation with the diet and lifestyle of each population in health and disease, the ability to communicate at the cellular level with the host through innate and adaptative immune receptors, and therefore an important role in modulating inflammatory process related to the establishment and progression of cancer. The oral cavity is one of the most important interaction windows between the human body and the environment, allowing the entry of an important number of microorganisms and their passage across the gastrointestinal tract and lungs. In this review, the contribution of the microbiome network to the establishment of systemic diseases like cancer is analyzed through their synergistic interactions and bidirectional crosstalk in the oral-gut-lung axis as well as its communication with the host cells. Moreover, the impact of the characteristic microbiota of each population in the formation of the multiomics molecular metafirm of the oral-gut-lung axis is also analyzed through state-of-the-art sequencing techniques, which allow a global study of the molecular processes involved of the flow of the microbiota environmental signals through cancer-related cells and its relationship with the establishment of the transcription factor network responsible for the control of regulatory processes involved with tumorigenesis.

Microbial infections as potential risk factors for lung cancer: Investigating the role of human papillomavirus and chlamydia pneumoniae

Background

Lung cancer is the leading cause of cancer morbidity and mortality worldwide. Apart from tobacco smoke and dietary factors, microbial infections have been reported as the third leading cause of cancers globally. Deciphering the association between microbiome and lung cancer will provide potential biomarkers and novel insight in lung cancer progression. In this current study, we performed a meta-analysis to decipher the possible association between C. pneumoniae and human papillomavirus (HPV) and the risk of lung cancer.

Methods

Literature search was conducted in most English and Chinese databases. Data were analyzed using CMA v.3.0 and RevMan v.5.3 software (Cochrane-Mantel-Haenszel method) by random-effects (DerSimonian and Laird) model.

Results

The overall pooled estimates for HPV studies revealed that HPV infections in patients with lung cancer were significantly higher than those in the control group (OR = 2.33, 95% CI = 1.57-3.37, p < 0.001). Base on subgroup analysis, HPV infection rate was significantly higher in Asians (OR = 6.38, 95% CI = 2.33-17.46, p < 0.001), in tissues (OR = 5.04, 95% CI = 2.27-11.19, p < 0.001) and blood samples (OR = 1.40, 95% CI = 1.02-1.93, p = 0.04) of lung cancer patients but non-significantly lower in males (OR = 0.84, 95% CI = 0.57-1.22, p =0.35) and among lung cancer patients at clinical stage I-II (OR = 0.95, 95% CI = 0.61-1.49, p = 0.82). The overall pooled estimates from C. pneumoniae studies revealed that C. pneumoniae infection is a risk factor among lung cancer patients who are IgA seropositive (OR = 1.88, 95% CI = 1.30-2.70, p < 0.001) and IgG seropositive (OR = 1.50, 95% CI = 1.10-2.04, p = 0.010). All seronegative IgA (OR = 0.69, 95% CI = 0.42-1.16, p = 0.16) and IgG (OR = 0.66, 95% CI = 0.42-105, p = 0.08) titers are not associative risk factors to lung cancer.

Conclusions

Immunoglobulin (IgA) and IgG seropositive titers of C. pneumoniae and lungs infected with HPV types 16 and 18 are potential risk factors associated with lung cancer.

Bronchial Microbiota and the Stress Associated with Invasive Diagnostic Tests in Lung Cancer vs. Benign Pulmonary Diseases: A Cross-Sectional Study

Lung cancer is the leading cause of cancer-related deaths worldwide. This study aimed to compare the bronchial microbiota of patients with lung cancer and patients with benign pulmonary diseases undergoing bronchoscopy, and to assess the stress levels associated with invasive diagnostic lung tests. A cross-sectional study was conducted at the "Victor Babes" Hospital for Infectious Diseases and Pulmonology in Timisoara, Romania. A total of 33 patients with histologically diagnosed bronchopulmonary cancer and 33 control patients with benign lung pathologies underwent bronchoscopy. Bronchial microbiota was analyzed by multiplex PCR, culture media, and cytology. Anxiety and depression levels were assessed using the ECOG performance status scale, Karnofsky scale, GAD-7, PHQ-9, and HADS questionnaires. There were no significant differences in the presence of common microbial species between the two groups, except for Acinetobacter spp. Which was identified in 15.2% of patients with lung cancer and 0.0% in the control group, Candida spp. Was more prevalent in the benign group (24.2% vs. 6.1%), and the Parainfluenza virus was detected only in the malignant group (21.1% vs. 0.0%). Cytology results showed a higher prevalence of atypical and tumoral cells in the malignant group (39.4% and 30.0%, respectively), as well as higher lymphocyte levels in the benign group (69.7% vs. 24.2%). Patients with lung cancer had significantly lower performance status on the ECOG scale (2.34 vs. 1.92), lower Karnofsky scores (71.36 vs. 79.43), and higher GAD-7 and PHQ-9 scores at the initial evaluation compared to the benign group. At the 90-day follow-up, ECOG and Karnofsky scores remained significantly different from the initial evaluation, but only GAD-7 scores showed a significant difference between the two groups. There were differences in the bronchial microbiota between patients with lung cancer and benign pulmonary diseases, with a higher prevalence of Candida spp. in the benign group and exclusive detection of Acinetobacter spp. and Parainfluenza virus in the malignant group. Patients with lung cancer exhibited higher stress levels, more severe anxiety, and depression symptoms, which persisted during follow-up. Further research is needed to understand the role of bronchial microbiota in lung cancer and the impact of stress on patient outcomes.

The lung, the niche, and the microbe: Exploring the lung microbiome in cancer and immunity

The lung is a complex and unique organ system whose biology is strongly influenced by environmental exposure, oxygen abundance, connection to extrapulmonary systems via a dense capillary network, and an array of immune cells that reside in the tissue at steady state. The lung also harbors a low biomass community of commensal microorganisms that are dynamic during both health and disease with the capacity to modulate regulatory immune responses during diseases such as cancer. Lung cancer is the third most common cancer worldwide with the highest mortality rate amongst cancers due to the difficulty of an early diagnosis. This review discusses the current body of work addressing the interactions between the lung microbiota and the immune system, and how these two components of the pulmonary system are linked to lung cancer development and outcomes. Bringing in lessons from broader studies examining the effects of the gut microbiota on cancer outcomes, we highlight many challenges and gaps in this nascent field.

The Function and Molecular Mechanism of Commensal Microbiome in Promoting Malignant Progression of Lung Cancer

The human commensal microbiome existing in an internal environment is relatively consistent with that of the host. The presence of bacterial dysbiosis, on the other hand, promptly results in the termination of this symbiotic association. The altered microbial structure in the lung may be responsible for the development of lung cancer by controlling the host's inflammatory response and influencing a variety of immunological pathways. More and more studies have pointed to the fact that the commensal microbiota plays a vital role in both the development of tumors and the body's response to lung cancer treatment. Microbiome dysbiosis, genotoxicity, virulence effect, and epigenetic dysregulations are some of the potential mechanisms that may lie behind the process of tumorigenesis that is mediated by microbiome. Other potential mechanisms include regulating host immune activity through a variety of pathogenic factors, dysregulating host metabolism as a result of microbiome alterations, and microbiome dysbiosis. In this historical overview, we go through some of the more recent mechanistic discoveries into the biological processes that are involved in lung cancer that are caused by bacteria. Without a question, obtaining a greater knowledge of the dynamic link between the lung microbiome and lung cancer has the potential to inspire the development of innovative early detection and customized treatment methods for lung cancer.

Microbiome dysbiosis and epigenetic modulations in lung cancer: From pathogenesis to therapy

The lung microbiome plays an essential role in maintaining healthy lung function, including host immune homeostasis. Lung microbial dysbiosis or disruption of the gut-lung axis can contribute to lung carcinogenesis by causing DNA damage, inducing genomic instability, or altering the host's susceptibility to carcinogenic insults. Thus far, most studies have reported the association of microbial composition in lung cancer. Mechanistic studies describing host-microbe interactions in promoting lung carcinogenesis are limited. Considering cancer as a multifaceted disease where epigenetic dysregulation plays a critical role, epigenetic modifying potentials of microbial metabolites and toxins and their roles in lung tumorigenesis are not well studied. The current review explains microbial dysbiosis and epigenetic aberrations in lung cancer and potential therapeutic opportunities.

Anti-lung cancer properties of cyanobacterial bioactive compounds

Lung cancer, the most prevalent gender-independent tumor entity in both men and women, is among the leading cause of cancer-related deaths worldwide. Despite decades of effort in developing improved therapeutic strategies including immunotherapies and novel chemotherapeutic agents, only modest improvements in outcome and long-term survival of lung cancer patients have been achieved. Therefore, exploring new and exceptional sources for bioactive compounds that might serve as anti-cancer agents might be the key to improving lung cancer therapy. On account of diverse forms, cyanobacteria might serve as a potential source for compounds with potential therapeutic applicability against malignant disorders, including cancer. The assorted arrays of metabolic mechanisms synthesize a plethora of bioactive compounds with immense biological potential. These compounds have been proven to be effective against various cancer cell lines and xenograft animal models. The present review provides an overview of the most promising cyanobacteria-derived bioactive compounds proven to exhibit anti-cancer properties in in-vitro and in-vivo studies and highlights their applicability as potential therapeutic agents with a focus on their anti-lung cancer properties.

Assessment of MDA and 8-OHdG expressions in ovine pulmonary adenocarcinomas by immunohistochemical and immunofluorescence methods

This study aimed to reveal the presence of reactive oxygen species (ROS)-induced lipid peroxidation and DNA damage in ovine pulmonary adenocarcinomas (OPA) by evaluating malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG) expressions by immunohistochemical and immunofluorescence methods. Lung tissue samples were collected from 26 sheep brought to the Pathology Department for routine diagnosis. Lung tissues were fixed in 10% neutral buffered formalin, following routine procedures tissues were stained with hematoxylin and eosin. Avidin-Biotin Peroxidase method was used as immunohistochemical staining. Indirect immunofluorescence method was applied to the sections. Tumoral cells showed acinar, papillary or mixed type patterns. Only 2 of 20 cases metastasized to regional lymph nodes. All OPAs were immune positive for Jaagsiekte Sheep Retrovirus Capsid Protein (JSRV CA), MDA and 8-OHdG. The control group was negative for JSRV CA, MDA and 8-OHdG expressions. Malondialdehyde and 8-OHdG immune positive cells were statistically increased in the OPA group compared to the control group. In conclusion, our results demonstrate that higher MDA and 8-OHdG expressions in sheep with OPA suggest that OPA may be closely related to lipid peroxidation and oxidative DNA damage.