Potential role of intratumor bacteria in mediating tumor resistance to the chemotherapeutic drug gemcitabine

Growing evidence suggests that microbes can influence the efficacy of cancer therapies. By studying colon cancer models, we found that bacteria can metabolize the chemotherapeutic drug gemcitabine (2',2'-difluorodeoxycytidine) into its inactive form, 2',2'-difluorodeoxyuridine. Metabolism was dependent on the expression of a long isoform of the bacterial enzyme cytidine deaminase (CDDL), seen primarily in Gammaproteobacteria. In a colon cancer mouse model, gemcitabine resistance was induced by intratumor Gammaproteobacteria, dependent on bacterial CDDL expression, and abrogated by cotreatment with the antibiotic ciprofloxacin. Gemcitabine is commonly used to treat pancreatic ductal adenocarcinoma (PDAC), and we hypothesized that intratumor bacteria might contribute to drug resistance of these tumors. Consistent with this possibility, we found that of the 113 human PDACs that were tested, 86 (76%) were positive for bacteria, mainly Gammaproteobacteria.
Source: ScienceNOW - Category: Science Authors: Tags: Medicine, Diseases reports Source Type: news

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Authors: Buck E, Sprick M, Gaida MM, Grüllich C, Weber TF, Herpel E, Bruckner T, Koschny R Abstract Recently, a tumor-autonomous cytochrome P450 (CYP)-3A5-mediated resistance to cancer therapy has been demonstrated in pancreatic ductal adenocarcinoma. Expression of CYP3A5, which is involved in the degradation of irinotecan, has also been reported in colorectal cancer (CRC). The aim of the present study was to analyze CYP3A5 expression in the normal colon, colon adenoma, CRC and normal tissues, as well as to examine whether CYP3A5 expression in CRC has an impact on tumor response to irinotecan treatment. Immuno...
Source: Oncology Letters - Category: Cancer & Oncology Tags: Oncol Lett Source Type: research
Conditions:   Colon Neoplasm;   Colon Adenocarcinoma;   Colon Cancer;   Colo-rectal Cancer;   Rectal Cancer;   Rectal Neoplasms;   Rectal Adenocarcinoma;   Rectal Tumors;   Pancreatic Cancer;   Pancreas Cancer;   Pancreatic Neoplasms;   Pancreatic Adenocarcinoma Intervention:   Diagnostic Test: Analysis of molecular tumor particularities and neoepitopes Sponsor:   Centogene AG Rostock Not yet recruiting
Source: ClinicalTrials.gov - Category: Research Source Type: clinical trials
CONCLUSION: Pancreas is not a common location for metastases; however, colon, stomach, kidney and lung seem to be the most common primary tumors with metastases to the pancreas. Our report is the first study about pancreatic metastatic tumors from Iran. PMID: 30821161 [PubMed - in process]
Source: Archives of Iranian Medicine - Category: Middle East Health Authors: Tags: Arch Iran Med Source Type: research
Publication date: Available online 9 November 2018Source: Cancer GeneticsAuthor(s): Eveline E. Vietsch, Garrett T. Graham, Justine N. McCutcheon, Aamir Javaid, Giuseppe Giaccone, John L. Marshall, Anton WellsteinCancer is a heterogeneous disease harboring diverse subclonal populations that can be discriminated by their DNA mutations. Environmental pressure selects subclones that ultimately drive disease progression and tumor relapse. Circulating cell-free DNA (ccfDNA) can be used to approximate the mutational makeup of cancer lesions and can serve as a marker for monitoring disease progression at the molecular level withou...
Source: Cancer Genetics - Category: Cancer & Oncology Source Type: research
Publication date: Available online 9 November 2018Source: Cancer GeneticsAuthor(s): Eveline E. Vietsch, Garrett T. Graham, Justine N. McCutcheon, Aamir Javaid, Giuseppe Giaccone, John L. Marshall, Anton WellsteinCancer is a heterogeneous disease harboring diverse subclonal populations that can be discriminated by their DNA mutations. Environmental pressure selects subclones that ultimately drive disease progression and tumor relapse. Circulating cell-free DNA (ccfDNA) can be used to approximate the mutational makeup of cancer lesions and can serve as a marker for monitoring disease progression at the molecular level withou...
Source: Cancer Genetics - Category: Cancer & Oncology Source Type: research
CONCLUSION: In Burkina Faso rural area, primary digestive cancers occur in young patients with no predominance of sex. Colorectal cancer remains the most common. PMID: 30392708 [PubMed - as supplied by publisher]
Source: Bulletin du Cancer - Category: Cancer & Oncology Authors: Tags: Bull Cancer Source Type: research
Oncogenic Kras are genetic dependencies for the majority of pancreatic and colorectal adenocarcinomas; however, much remains to be understood regarding its tropism to these carcinomas. Recently developed organoid technology presents a more representative model culture system for pancreatic and colon epithelial tissues as well as better fostering the culture of nonimmortalized cells than two-dimensional culture. These advantages enable cancer researchers to directly compare tumor and normal tissue models to better study tumor initiation as well as therapeutic efficacy. Although in vivo models better model the complexity of ...
Source: Cold Spring Harbor perspectives in medicine - Category: Research Authors: Tags: Ras and Cancer in the 21st Century TECHNIQUE Source Type: research
Conclusion: Radiolabeled FAPIs allow fast imaging with very high contrast in tumors having a high stromal content and may therefore serve as pantumor agents. Coupling of these molecules to DOTA or other chelators allows labeling not only with 68Ga but also with therapeutic isotopes such as 177Lu or 90Y.
Source: Journal of Nuclear Medicine - Category: Nuclear Medicine Authors: Tags: Translational Source Type: research
ConclusionsThe synchronous sigmoid colon cancer and pancreatic cystic incidentaloma is a rare presentation, which, to the best of our knowledge, has not been reported in the literature. We report the surgical management of this case and present a review of the literature. Genetic studies may be conducted to find out whether there is common genetic mutation resulting in these two malignancies, and may be helpful in screening programs.
Source: Journal of Medical Case Reports - Category: General Medicine Source Type: research
Mutations or other alterations in theRET gene have been implicated in a variety of malignancies – most commonly thyroid, but also chronic myelomonocytic leukemia, acute myeloid leukemia, and lung, breast, pancreatic, and colon cancers. Here we present a case of a gentlemen initially diagnosed with and treated for non-small cell lung adenocarcinoma. Genomic profiling of his tumor specimen rev ealed aRET point mutation with a known association with medullary thyroid cancer (MTC). Further pathological and molecular diagnostic evaluation confirmed a diagnosis of MTC, leading to a change in treatment from standard chemoth...
Source: Case Reports in Oncology - Category: Cancer & Oncology Source Type: research
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