{
  "abstract": "Docetaxel (DTX) is a widely used chemotherapeutic agent for breast cancer; however, its clinical application is limited by dose-dependent toxicity and chemoresistance. This study investigated the chemosensitizing potential of a native dairy-derived S. thermophilus strain in combination with DTX against MCF-7 breast cancer cells. Sixty traditional fermented dairy samples collected from Fars Province, Iran, were screened for lactic acid bacteria. The selected isolate was identified by 16 S rRNA gene sequencing as S. thermophilus Ab.341 TH and deposited in GenBank under accession number PX307500. Cytotoxicity was evaluated by MTT assay in MCF-7 breast cancer cells and MCF-10 A non-tumorigenic mammary epithelial cells. Apoptosis-related gene expression was analyzed by quantitative real-time PCR, and apoptotic cell death was evaluated using Annexin V-FITC/PI flow cytometry. S. thermophilus Ab.341 TH reduced MCF-7 cell viability in a concentration-dependent manner while exhibiting limited effects on MCF-10 A cell viability under the tested conditions. DTX alone showed an IC₅₀ of approximately 30 µg/mL, whereas combination treatment with S. thermophilus (OD₆₀₀ = 0.85) reduced the effective DTX concentration to 150 ng/mL, representing an approximately 200-fold reduction in the concentration required to achieve comparable cytotoxic effects in vitro. Combination treatment increased the expression of apoptosis-associated genes, including Caspase-3, Caspase-8, Caspase-9, BAX, Fas, PTEN, P53, and P21, while decreasing the expression of survival-related genes including AKT, mTOR, and BCL-2. Increased IκB expression suggested modulation of NF-κB-associated signaling responses. Flow cytometry confirmed enhanced apoptotic cell death, with 23.52% early and 20.56% late apoptotic populations and minimal necrosis. S. thermophilus Ab.341 TH enhances MCF-7 breast cancer cell sensitivity to docetaxel under in vitro conditions through modulation of apoptosis-associated and survival-related gene expression patterns. These findings support the potential application of this native probiotic strain as a biological chemosensitizer; however, further mechanistic validation, in vivo studies, and pharmacological synergy analyses are required to determine its translational relevance. Illustrating the proposed chemosensitizing anticancer mechanism of the dairy-derived probiotic S. thermophilus Ab.341 TH in combination with docetaxel (DTX) against MCF-7 breast cancer cells. S. thermophilus enhances the antitumor activity of DTX by activating both the intrinsic (mitochondrial) and extrinsic (death receptor) apoptotic pathways through upregulation of Caspase-3, Caspase-8, Caspase-9, BAX, PTEN, P53, P21 , and Fas, while suppressing the PI3K/AKT/mTOR survival signaling axis and reducing BCL-2 expression. The combination treatment markedly decreases the effective in vitro concentration of DTX (approximately 200-fold) while enhancing apoptotic cell death and docetaxel responsiveness in breast cancer cells, suggesting the potential of S. thermophilus Ab.341 TH as a probiotic-assisted chemosensitizing strategy.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "Abbas Asoudeh-Fard"
    },
    {
      "name": "Farnood Afrakhteh"
    },
    {
      "name": "Ali Sarajzadeh Fard"
    },
    {
      "name": "Ahmad Gholami"
    },
    {
      "name": "Maryam Homayoon"
    },
    {
      "name": "Mohammad Bagher Nazari"
    },
    {
      "name": "Mohammad Abbasi"
    },
    {
      "name": "Asghar Parsaei"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3w3c5n0tc338z.bib",
  "cited_by": 0,
  "doi": "10.1186/s12866-026-05666-5",
  "fulltext_url": null,
  "id": "3w3c5n0tc338z",
  "issns": [
    "1471-2180"
  ],
  "landing_url": "https://hal.science/hal-05767923v1",
  "language": "en",
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sde"
    ],
    [
      "openalex",
      "1106|Probiotics and Fermented Foods"
    ]
  ],
  "openalex": "W7213762470",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-21",
  "publisher": "BioMed Central",
  "ris": "https://research.draconitic.com/paper/3w3c5n0tc338z.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:42Z",
      "native_id": "hal-05767923",
      "source": "hal",
      "url": "https://hal.science/hal-05767923v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "hal:0.sde",
      "subfield": "environmental-science"
    }
  ],
  "title": "A native dairy-derived Streptococcus thermophilus potentiates docetaxel efficacy by modulating apoptotic and PI3K/AKT/mTOR signaling pathways in MCF-7 breast cancer cells",
  "title_text": "A native dairy-derived Streptococcus thermophilus potentiates docetaxel efficacy by modulating apoptotic and PI3K/AKT/mTOR signaling pathways in MCF-7 breast cancer cells",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:42Z",
  "url": "https://research.draconitic.com/paper/3w3c5n0tc338z",
  "venue": "BMC Microbiology",
  "versions": []
}