Biology subjects

Puolakkainen, P.

Publications and source records attributed to Puolakkainen, P..

3 recordsLinked to original sources

bioRxiv2025

Therapeutic Eradication of Cancer-associated Fibroblasts Inhibits in vivo progression of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a lethal disease with an unmet medical need. therapeutic elimination of cancer associated fibroblasts (CAFs), key drivers of tumor aggressiveness, has been the focus of recent studies. However, the inherent heterogeneity and plasticity of CAFs have hampered the development of CAF-targeted therapies. Clemastine, an FDA-approved cationic amphiphilic drug, is known to elicit cytotoxic lysosomal membrane permeabilization in solid tumors. We evaluated its efficacy in patient derived PDAC organoids and patient avatars. In vitro, half of the organoids responded to clemastine, although sensitivity did not predict in vivo outcomes. In vivo, clemastine treatment led to CAF depletion, halted cancer progression and delayed disease progression. To assess potential synergy with standard-of-care therapy, clemastine was combined with gemcitabine. The combination enabled dual targeting--clemastine effectively eliminated all CAF subtypes, while gemcitabine eradicated cancer cells - leading to inhibition of metastatic dissemination. These findings support clemastine as a promising companion therapy in PDAC, targeting the tumor-supportive microenvironment.

cancer biology↗

bioRxiv2025

Sustained epithelial interferon signaling modulates incomplete pathologic response in colorectal cancer

Background & AimsPatients with colorectal cancer have heterogeneous clinical responses to chemotherapy, although clinical guidelines advise little variability in treatment selection based on molecular tumor features. Precision oncology research typically utilizes patient-derived tumor organoids (PDTO) to predict clinical outcomes, but such efforts are often not directed towards identification of molecular factors underlying differential responses to therapy. MethodsBulk RNA-sequencing was performed on treatment-naive PDTOs, and gene expression data was combined to drug sensitivity data to identify transcriptomic features associated with low in vitro sensitivity to chemotherapy. Whole-exome sequencing was performed on primary tumors to infer the somatic mutations of PDTOs and used to identify somatic mutations associated with differential in vitro drug responses. Publicly available gene expression and drug sensitivity data sets were used to validate the results. RNA interference was used for functional validation. ResultsPDTOs with low chemosensitivity had high JAK-STAT pathway activity resulting from high expression of interferon-stimulated genes. Evidence from single-cell RNA-sequencing confirmed chemotherapy-induced expression of interferon-stimulated genes in epithelial cells of cancers with partial response. EPSTI1 knockdown decreased cancer cell viability and sensitized cells to chemotherapy. ConclusionsSustained interferon signaling in epithelial cancer cells contributes to incomplete pathologic response in colorectal cancer. The findings highlight the potential of JAK-STAT inhibition or TRAIL pathway activation to enhance chemotherapy efficacy. Future studies investigating pharmacologic modulation of these pathways in preclinical CRC models are needed to determine their viability as therapeutic targets.

cancer biology↗

bioRxiv2022

Efficacy and safety of glycosphingolipid SSEA-4 targeting CAR-T cells in solid tumors

Chimeric antigen receptor (CAR) T-cell immunotherapies for solid tumors face critical challenges such as heterogeneous antigen expression. We characterized SSEA-4 cell-surface glycolipid as a target for CAR-T cell therapy. SSEA-4 is mainly expressed during embryogenesis but is also found in several cancer types making it an attractive tumor-associated antigen. Anti-SSEA-4 CAR-T cells were generated and assessed pre-clinically in vitro and in vivo for anti-tumor response and safety. SSEA-4 CAR-T cells effectively eliminated SSEA-4 positive cells in all tested cancer cell lines whereas SSEA-4 negative cells lines were not targeted. In vivo efficacy and safety studies using NSG mice and the high-grade serous ovarian cancer cell line OVCAR4 demonstrated a remarkable and specific anti-tumor response at all CAR-T cell doses used. At high T cell doses, CAR-T cell-treated mice showed signs of health deterioration after a follow-up period. However, severity of toxicity was reduced with delayed onset when lower CAR-T cell doses were used. Our data demonstrate the efficacy of anti-SSEA-4 CAR-T therapy; however, safety strategies, such as dose-limiting and/or equipping CAR-T cells with combinatorial antigen recognition should be implemented for its potential clinical translation.

cancer biology↗