The presence of intratumoral Porphyromonas gingivalis correlates with a previously defined pancreatic adenocarcinoma, immune cell expression phenotype and with tumor resident, adaptive immune receptor features.

The association between pancreatic adenocarcinoma (PAAD) and the pancreatic microbiome is not fully understood, although bacteria may decrease the effectiveness of chemotherapy and lead to anti-apoptotic, pro-inflammatory-microenvironments. To better understand the relationship between the PAAD microbiome and the microenvironment, we identified Porphyromonas gingivalis-positive PAAD samples and found a strong association between intratumoral Porphyromonas gingivalis and: (a) an immune cell gene expression phenotype previously defined by others as gene program 7; and (b) recovery of immunoglobulin recombination, sequencing reads. We applied a novel chemical complementarity scoring algorithm, suitable for a big data setting, and determined that the previously established, Porphyromonas gingivalis antigen, rpgB had a reduced chemical complementarity with T-cell receptor (TCR) complementarity-determining region-3 amino acid sequences recovered from PAAD samples with Porphyromonas gingivalis in comparison to TCR-rpgB chemical complementarity represented by the PAAD samples that lacked Porphyromonas gingivalis. This finding strengthens the existing body of evidence correlating Pophyromonas gingivalis with PAAD, which may have implications for treatment and prognosis of patients. Furthermore, demonstrating the correlation of Pophryomonas gingivalis and gene program 7 raises the question of whether Pophryomonas gingivalis infection is responsible for the gene program 7 subdivision of PAAD

Bacterial Sequencing Reads in Blood Exome Files from Melanoma and Cervical Cancer Patients are Associated with Cancer Recurrence.

Bacteremia poses great risk for morbidity and mortality for immunocompromised cancer patients. Although the presence of bacteria within solid tumors is gaining greater attention, few studies have analyzed species of bacteria in the blood and their effect on cancer clinical outcomes. Using the Kraken 2 taxonomic profiling tool, we classified bacteria present in blood and primary tumors of cervical cancer and melanoma cases. The Cancer Genome Atlas (TCGA) melanoma blood exome files with Pseudomonas species were found to represent a worse disease-free survival (DFS) probability, while a worse overall survival (OS) result was evidenced for both the TCGA and Moffitt Cancer Center melanoma datasets. Cervical cancer cases with reads representing the Bradyrhizobium genus and Bradyrhizobium sp. BTAi1 found in blood and tumor exome files were found to have lower DFS. Additionally, reduced DFS and OS were observed for cervical cancer cases positive for Bacteroides species including Bacteroides fragilis. This study provides novel evidence and a novel approach for indicating that bacteria in blood is associated with cancer recurrence. These findings may guide the development of more efficient prognostic and screening tools related to bacterial blood infections of melanoma and cervical cancer patients