Trp53R172H and kmsg12d cooperate to promote chromosomal instability and widely metastatic pancreatic ductal adenocarcinoma in mice

Tumor-associated macrophages (TAM) are prominent components of tumor microenvironment (TME) and capable of promoting cancer progression. However, the mechanisms for the formation of M2-like TAMs remain enigmatic. Here, we show that lactate is a pivotal oncometabolite in the TME that drives macrophage M2-polarization to promote breast cancer proliferation, migration, and angiogenesis. In addition, we identified that the activation of ERK/STAT3, major signaling molecules in the lactate signaling pathway, deepens our molecular understanding of how lactate educates TAMs. Moreover, suppression of ERK/STAT3 signaling diminished tumor growth and angiogenesis by abolishing lactate-induced M2 macrophage polarization. Finally, research data of the natural compound withanolide D provide evidence for ERK/STAT3 signaling as a potential therapeutic strategy for the prevention and treatment of breast cancer. These findings suggest that the lactate-ERK/STAT3 signaling pathway is a driver of breast cancer progression by stimulating macrophage M2-like polarization and reveal potential new therapeutic targets for breast cancer treatment.

https://www.tandfonline.com/doi/pdf/10.1080/15384101.2018.1444305

Tumor-derived lactate induces M2 macrophage polarization via the activation of the ERK/STAT3 signaling pathway in breast cancer

Therapeutic resistance of pancreatic cancer: Roadmap to its reversal

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal solid malignancies with very few therapeutic options to treat advanced or metastatic disease. The utilization of genomic sequencing has identified therapeutically relevant alterations in approximately 25% of PDAC patients, most notably in the DNA damage response and repair (DDR) genes, rendering cancer cells more sensitive to DNA-damaging agents and to DNA damage response inhibitors, such as PARP inhibitors. ATM is one of the most commonly mutated DDR genes, with somatic mutations identified in 2% to 18% of PDACs and germline mutations identified in 1% to 34% of PDACs. ATM plays a complex role as a cell-cycle checkpoint kinase, regulator of a wide array of downstream proteins, and responder to DNA damage for genome stability. The disruption of ATM signaling leads to downstream reliance on ATR and CHK1, among other DNA-repair mechanisms, which may enable exploiting the inhibition of downstream proteins as therapeutic targets in ATM-mutated PDACs. In this review, we detail the function of ATM, review the current data on ATM deficiency in PDAC, examine the therapeutic implications of ATM alterations, and explore the current clinical trials surrounding the ATM pathway.

/pdf/atm-dysfunction-in-pancreatic-adenocarcinoma-and-associated-16pdjojn6t.pdf

ATM Dysfunction in Pancreatic Adenocarcinoma and Associated Therapeutic Implications.

Inhibiting RRM2 to enhance the anticancer activity of chemotherapy.

// Jingkai Zhou 1 , Tiangang Zhao 2 , Linfeng Ma 2 , Min Liang 2 , Ying-Jie Guo 2 and Li-Mei Zhao 1 1 Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, China 2 School of Life Sciences, Jilin University, Changchun, China Correspondence to: Ying-Jie Guo, email: guoyingjie@jlu.edu.cn Li-Mei Zhao, email: zhaolm@sj-hospital.org Keywords: cucurbitacin B, SCH772984, pancreatic cancer, EGFR, ERK Received: June 29, 2017      Accepted: September 21, 2017      Published: October 09, 2017 ABSTRACT Cucurbitacin B (CuB) is a natural tetracyclic triterpene product and displays antitumor activity across a wide array of cancers. In this study, we explored the anti-pancreatic cancer activity of CuB alone and in combination with SCH772984, an ERK inhibitor, in vitro and in vivo . CuB inhibited proliferation of pancreatic cancer cells by arresting them in the G2/M cell cycle phase. This was associated with inhibition of EGFR expression and activity and downstream signaling, including PI3K/Akt/mTOR and STAT3. Interestingly, ERK activity was markedly enhanced by activating AMPK signaling after 12 h of CuB treatment. SCH772984 potentiates the cytotoxic effect of CuB on pancreatic cancer cells through complementary inhibition of EGFR, PI3K/Akt/mTOR, STAT3 and ERK signaling, followed by an increase in the pro-apoptotic protein Bim and a decrease in the anti-apoptotic proteins Mcl-1, Bcl-2, Bcl-xl and survivin. Furthermore, combined therapy with CuB and SCH772984 resulted in highly significant growth inhibition of pancreatic cancer xenografts. These results may provide a basis for further development of combining CuB and ERK inhibitors to treat pancreatic cancer.

/pdf/cucurbitacin-b-and-sch772984-exhibit-synergistic-anti-1dgs6s9wu4.pdf

Cucurbitacin B and SCH772984 exhibit synergistic anti-pancreatic cancer activities by suppressing EGFR, PI3K/Akt/mTOR, STAT3 and ERK signaling

Inhibition of checkpoint kinase 1 (CHK1) is a promising therapeutic strategy to increase the effectiveness of DNA-damaging drugs in pancreatic cancer. However, owing to the multiple roles of CHK1 in the DNA damage response (DDR) pathway, the molecular mechanism of chemosensitization by CHK1 inhibitors is not definitive. In the present study, we explored the antitumor mechanism of LY2603618, a specific CHK1 inhibitor, alone or in combination with gemcitabine in 5 pancreatic cancer cell lines. LY2603618 treatment of the pancreatic cancer cell lines resulted in growth inhibition, with IC50 values ranging from 0.89 to 2.75 µM, but limited cell death. Importantly, treatment of pancreatic cancer cell lines with LY2603618 reduced the levels of pCDC25C, pCDK1, and pCDK2, accompanied by DNA damage and RRM1/2 downregulation. Furthermore, LY2603618 synergized with gemcitabine treatment to induce growth inhibition and apoptosis in pancreatic cancer cells. Mechanistic investigations showed that gemcitabine sensitization by CHK1 inhibition was associated with CDK‑dependent RRM1/2 downregulation and DNA damage enhancement. These findings provide a basis for further development of combining CHK1 inhibitors and gemcitabine to treat pancreatic cancer.

/pdf/chk1-inhibition-sensitizes-pancreatic-cancer-cells-to-409ehs0ih7.pdf

Tiangang Zhao

Papers

Cucurbitacin B and SCH772984 exhibit synergistic anti-pancreatic cancer activities by suppressing EGFR, PI3K/Akt/mTOR, STAT3 and ERK signaling

CHK1 inhibition sensitizes pancreatic cancer cells to gemcitabine via promoting CDK-dependent DNA damage and ribonucleotide reductase downregulation