Synergistic Nanomedicine Delivering Topoisomerase I Toxin (SN-38) and Inhibitors of Polynucleotide Kinase 3′-Phosphatase (PNKP) for Enhanced Treatment of Colorectal Cancer

Article

作者: Hall, Dennis G ; Paladino, Marco ; Weinfeld, Michael ; Lavasanifar, Afsaneh ; Abd-El Hafeez, Sara I ; Sadat, Sams M A ; Vakili, Mohammad Reza

Inhibitors of a DNA repair enzyme known as polynucleotide kinase 3'-phosphatase (PNKP) are expected to show synergistic cytotoxicity in combination with topoisomerase I (TOP1) inhibitors in cancer. In this study, the synergistic cytotoxicity of a novel inhibitor of PNKP, i.e., A83B4C63, with a potent TOP1 inhibitor, i.e., SN-38, against colorectal cancer cells was investigated. Polymeric micelles (PMs) for preferred tumor delivery of A83B4C63, developed through physical encapsulation of this compound in methoxy poly(ethylene oxide)-poly(α-benzyl carboxylate-ε-caprolactone) (mPEO-b-PBCL) micelles, were combined with SN-38 in free or PM form. The PM form of SN-38 was prepared through chemical conjugation of SN-38 to the functional end group of mPEO-b-PBCL and further assembly of mPEO-b-PBCL-SN-38 in water. Moreover, mixed micelles composed of mPEO-b-PBCL and mPEO-b-PBCL-SN-38 were used to co-load A83B4C63 and SN-38 in the same nanoformulation. The loading content (% w/w) of the SN-38 and A83B4C63 to mPEO-b-PBCL in the co-loaded formulation was 7.91 ± 0.66 and 16.13 ± 0.11% (w/w), respectively, compared to 15.67 ± 0.34 (% w/w) and 23.06 ± 0.63 (% w/w) for mPEO-b-PBCL micelles loading individual drugs. Notably, the average diameter of PMs co-encapsulating both SN-38 and A83B4C63 was larger than that of PMs encapsulating either of these compounds alone but still lower than 60 nm. The release of A83B4C63 from PMs co-encapsulating both drugs was 76.36 ± 1.41% within 24 h, which was significantly higher than that of A83B4C63-encapsulated micelles (42.70 ± 0.72%). In contrast, the release of SN-38 from PMs co-encapsulating both drugs was 44.15 ± 2.61% at 24 h, which was significantly lower than that of SN-38-conjugated PMs (74.16 ± 3.65%). Cytotoxicity evaluations by the MTS assay as analyzed by the Combenefit software suggested a clear synergy between PM/A83B4C63 (at a concentration range of 10-40 μM) and free SN-38 (at a concentration range of 0.001-1 μM). The synergistic cytotoxic concentration range for SN-38 was narrowed down to 0.1-1 or 0.01-1 μM when combined with PM/A83B4C63 at 10 or 20-40 μM, respectively. In general, PMs co-encapsulating A83B4C63 and SN-38 at drug concentrations within the synergistic range (10 μM for A83B4C63 and 0.05-1 μM for SN-38) showed slightly less enhancement of SN-38 anticancer activity than a combination of individual micelles, i.e., A83B4C63 PMs + SN-38 PMs at the same molar concentrations. This was attributed to the slower release of SN-38 from the SN-38 and A83B4C63 co-encapsulated PMs compared to PMs only encapsulating SN-38. Cotreatment of cells with TOP1 inhibitors and A83B4C63 formulation enhanced the expression level of γ-HA2X, cleaved PARP, caspase-3, and caspase-7 in most cases. This trend was more consistent and notable for PMs co-encapsulating both A83B4C63 and SN-38. The overall result from the study shows a synergy between PMs of SN-38 and A83B4C63 as a mixture of two PMs for individual drugs or PMs co-encapsulating both drugs.

2022-01-01·International journal of biological sciences

TOP1 inhibition induces bifurcated JNK/MYC signaling that dictates cancer cell sensitivity

Article

作者: Unternaehrer, Juli ; Liu, Qizhi ; Cui, Yukun ; Zhang, Maoqi ; Cui, Xiaojiang ; Lee, Tian-Yu ; Tanaka, Hisashi ; Han, Bingchen ; Chung, Stacey ; Chirshev, Evgeny ; Gao, Bowen ; Murata, Michael M ; Giuliano, Armando E

Rationale: Triple-negative breast cancer (TNBC) does not respond to anti-estrogen and anti-HER2 therapies and is commonly treated by chemotherapy. TNBC has a high recurrence rate, particularly within the first 3 years. Thus, there is an urgent clinical need to develop more effective therapies for TNBC. Topoisomerase I (TOP1) inhibitors cause DNA damage, making these drugs desirable for TNBC treatment since DNA repair machinery is defective in this subtype of breast cancer. Among the main molecular subtypes of breast cancer, the TNBC cell lines exhibited the highest TOP1 inhibition sensitivity. However, clinically used TOP1 inhibitors, such as topotecan and irinotecan, have shown limited clinical applications and the reasons remain unclear. Understanding the mechanism of differential responses to TOP1 blockade and identifying the predictive markers for cancer cell sensitivity will help further TOP1-targeted therapy for TNBC treatment and improve the clinical use of TOP1 inhibitors. Methods: Viability assays were used to evaluate breast cancer cell sensitivity to topotecan and other TOP1 inhibitors as well as TOP2 inhibitors. An in vitro-derived topotecan-resistant TNBC cell model and TNBC xenograft models were employed to confirm cancer cell response to TOP1 blockade. RNA-seq was used to identify potential predictive markers for TNBC cell response to TOP1 blockade. Western blotting and qRT-PCR were performed to measure the protein levels and RNA expression. ATAC-seq and luciferase reporter assays were used to examine MYC transcriptional regulations. The effects of MYC and JNK in cancer cell response to TOP1 inhibition were validated via loss-of-function and gain-of-function experiments. Results: We observed two distinct and diverging cancer cell responses - sensitive versus resistant to TOP1 inhibition, which was confirmed by TNBC xenograft mouse models treated by topotecan. TNBC cells exhibited bifurcated temporal patterns of ATR pathway activation upon TOP1 inhibitor treatment. The sensitive TNBC cells showed an "up then down" dynamic pattern of ATR/Chk1 signaling, while the resistant TNBC cells exhibited a "persistently up" profile. On the contrary, opposite temporal patterns of induced expression of MYC, a key regulator and effector of DNA damage, were found in TNBC cells treated by TOP1 inhibitors. Mechanistically, we showed that TOP1-induced JNK signaling upregulated MYC expression. Furthermore, pharmacological inhibition of ATR reversed TNBC cell resistance to topotecan, whereas MYC knockdown and JNK inhibition reduced cancer cell sensitivity. Conclusions: Dynamic temporal profiles of induced ATR/Chk1 and JNK activation as well as MYC expression, may predict cancer cell response to TOP1 inhibitors. JNK activation-mediated constitutive elevation of MYC expression may represent a novel mechanism governing cancer cell sensitivity to TOP1-targeting therapy. Our results may provide implications for identifying TNBC patients who might benefit from the treatment with TOP1 inhibitors.

项与 TOP1靶向siRNA(北京键凯) 相关的新闻（医药）

2024-09-26

·EndPoints

Endpoints 11 winner MediLink Therapeutics: China startup helps power the ADC renaissance

In the ADC renaissance of the last few years, Japan’s venerable pharma company Daiichi Sankyo has won many of the headlines. But if MediLink Therapeutics has its way, Chinese biotechs will cement the treatments’ dominance in oncology — and prove that China’s new generation of drugmakers can truly compete on the global stage. MediLink has raised $120 million in funding and counts BioNTech and Roche as partners. The Suzhou-based company is at the forefront of a dealmaking wave in which multinational pharma companies have increasingly looked to China as a source of early drug candidates. And MediLink’s licensing deals with multinational pharmas are a bright spot amid growing US-China tensions that have cast a chill over much of the local industry’s work with US companies. The biotech, founded in 2020, came on the scene just as “nearly every pharma was looking for ADCs” again after the drugs had fallen out of favor a decade prior, said Jiaqiang Cai, MediLink’s co-founder and chief scientific officer. That wasn’t always the case. Cai previously worked at Sichuan Kelun-Biotech, which began pursuing ADCs in 2013 after the FDA approval of Roche’s Kadcyla sparked an ADC me-too frenzy in China. While he believed Kelun had a me-better molecule, at 2019’s JP Morgan conference in San Francisco, everyone turned him down for meetings to talk about licensing deals. They saw no future in ADCs, and “nobody believed everything we did in China at that time,” he said. A few months later, Merck came calling after AstraZeneca’s up to $7 billion ADC deal with Daiichi Sankyo stunned the industry. Merck licensed Kelun’s TROP2 ADC and eventually inked two more deals for other programs, each with billions of dollars in potential milestones. By then, Cai had left to work for another domestic pharma company in Shanghai. But Tony Xue, his former ADC partner at Kelun, wondered if they could repeat the success with a new startup and a new platform. “Kelun’s technology is actually very good for TROP2. But for many other targets, [it’s] probably too unstable, and also [the] potency is too high,” Cai said. That fine balance of delivering enough chemotherapy to kill cancer without poisoning the rest of the body has long been the key challenge for ADCs. MediLink works with a version of the standard antibody-linker-payload combo that is stable in healthy tissue and doesn’t require internalization of the antibody — meaning its cancer-killing drugs can be unleashed outside the cell, removing some barriers to efficacy. The concept isn’t new. But the way MediLink turned it into reality is emblematic of the fast, iterative engineering that’s helped many Chinese startups get ahead in the drug discovery race. The tiny team led by Xue, Cai and COO Joey Xiao came up with six different ideas of how to structure the payload-linker complex, then hired a CRO to test them all in parallel. They got to work in December 2020. Three months later, in February 2021, they had a molecule that met their criteria. And in June of that year, optimization was complete. “During six months, they made 200 molecules for us. And only six chemists,” he said. Roche made MediLink the first partner for its Shanghai R&D group, and sees the startup “as a fast-growing China biotech with R&D expertise and proprietary ADC platform technology, including differentiated TOP1 inhibitor payload and linker,” a spokesperson for the Swiss drugmaker said. There can be downsides to speed: MediLink and BioNTech’s HER3 ADC was placed on a clinical hold by regulators earlier this year after patient deaths were deemed related to treatment. The serious toxicity arose as MediLink expanded the patient cohort in a short period of time. “We moved too fast,” Cai told Endpoints. But he said the companies also reacted swiftly to pause enrollment and notify regulators. They ended up adjusting the dose, and the hold was lifted in August . With money from the out-licensing deals, MediLink has been able to grow its team to almost 180 people, even though it hasn’t raised any new venture funding since closing a $70 million Series B in 2022. With many of MediLink’s assets already claimed by a partner (before BioNTech and Roche, it also struck deals with Zai Lab, Harbour BioMed and Henlius) the company’s leaders are hoping to keep some candidates in-house before considering more deals, which Cai said would likely happen at a later phase. “For anything you try to license out, you need to get the idea earlier than others, and then you have something other people don’t have,” he said. When asked about concerns that promising data from Chinese patients wouldn’t translate in trials outside the country, Cai noted that the much higher body weight for US patients could skew the pharmacokinetics, and different dose settings may be required in different countries. “I believe eventually it will work,” he said. Key investors: LYFE Capital, Qiming Venture Partners, Legend Capital, Loyal Valley Capital, Apricot Capital, C&D Emerging Capital, Highlight Capital Find the full list of 2024 Endpoints 11 winners here .

抗体药物偶联物引进/卖出

2024-09-09

·GlobeNewswire-Health Care

Zentalis Pharmaceuticals to Present Preclinical Azenosertib Data at ESMO 2024

Azenosertib shows synergistic anti-tumor effects in combination with topoisomerase I (TOP1) inhibitor-based antibody drug conjugatesSAN DIEGO, Sept. 09, 2024 (GLOBE NEWSWIRE) -- Zentalis® Pharmaceuticals, Inc. (Nasdaq: ZNTL), a clinical-stage biopharmaceutical company discovering and developing clinically differentiated small molecule therapeutics targeting fundamental biological pathways of cancers, today announced that the company will present preclinical data from its selective WEE1 inhibitor azenosertib at the European Society of Medical Oncology (ESMO) 2024 Congress, occurring September 13-17 in Barcelona, Spain. “The confluence of DNA damage induced by TOP1 inhibitors and cell cycle deregulation and genomic instability induced by azenosertib provides a mechanistic rationale for this combination, as well as more broadly with antibody drug conjugates (ADCs) utilizing these inhibitors as payloads,” said Mark Lackner, PhD, Chief Scientific Officer. “The preclinical data demonstrated this synergistic effect and suggest that azenosertib in combination with ADCs could be an important therapeutic approach in treating patients with advanced solid tumors.” Presentation Details:Poster #35P: The Selective WEE1 Inhibitor Azenosertib Shows Synergistic Antitumor Effects in Combination with Topoisomerase I Inhibitor-Based Antibody-Drug ConjugatesPresenter: Jianhui Ma, Zentalis Pharmaceuticals Poster Display Date: Sunday, September 15, 2024 Data in the abstract showed that the combination of azenosertib with TOP1 inhibitors demonstrated significant synergistic effects in all cell lines tested. In HER2+ breast cancer animal models, those treated with the combination of azenosertib plus trastuzumab deruxtecan (T-Dxd) resulted in 50% of animals showing complete tumor regression (CR), compared with no CRs in monotherapy arms. Significant combination effects were also observed in a HER2+ ovarian model and a HER2-low breast cancer model. These data suggest that azenosertib significantly improves the anti-tumor effect of TOP1 inhibitors as well as ADCs with TOP1 inhibitor payload and that the combination could be a generalizable therapeutic approach for improving responses to ADCs in patients with advanced solid tumors. About AzenosertibAzenosertib is a novel, selective, and orally bioavailable inhibitor of WEE1 currently being evaluated as a monotherapy and combination clinical studies in ovarian cancer and additional tumor types. WEE1 acts as a master regulator of the G1-S and G2-M cell cycle checkpoints, through negative regulation of both CDK1 and CDK2, to prevent replication of cells with damaged DNA. By inhibiting WEE1, azenosertib enables cell cycle progression, despite high levels of DNA damage, thereby resulting in the accumulation of DNA damage and leading to mitotic catastrophe and cancer cell death. About Zentalis Pharmaceuticals Zentalis® Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company discovering and developing clinically differentiated small molecule therapeutics targeting fundamental biological pathways of cancers. The Company’s lead product candidate, azenosertib (ZN-c3), is a potentially first-in-class and best-in-class WEE1 inhibitor for advanced solid tumors and hematologic malignancies. Azenosertib is being evaluated as a monotherapy and in combination across multiple clinical trials and has broad franchise potential. In clinical trials, azenosertib has been well tolerated and has demonstrated anti-tumor activity as a single agent across multiple tumor types and in combination with several chemotherapy backbones. As part of its azenosertib clinical development program, the Company is exploring enrichment strategies targeting tumors of high genomic instability, such as Cyclin E1 positive tumors, homologous recombination deficient tumors and tumors with oncogenic driver mutations. The Company is also leveraging its extensive experience and capabilities across cancer biology and medicinal chemistry to advance its research on protein degraders. Zentalis has operations in San Diego. For more information, please visit www.zentalis.com. Follow Zentalis on X/Twitter at @ZentalisP and on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals. Forward-Looking StatementsThis press release contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including statements regarding the potential benefits of azenosertib in combination with ADCs as a therapeutic approach. The terms “could” and similar references are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our ability to resolve the ongoing partial clinical hold on azenosertib; our limited operating history, which may make it difficult to evaluate our current business and predict our future success and viability; we have and expect to continue to incur significant losses; our need for additional funding, which may not be available; our plans, including the costs thereof, of development of any diagnostic tools; our substantial dependence on the success of our lead product candidate, azenosertib; the outcome of preclinical testing and early trials may not be predictive of the success of later clinical trials; failure to identify additional product candidates and develop or commercialize marketable products; potential unforeseen events during clinical trials could cause delays or other adverse consequences; risks relating to the regulatory approval process or ongoing regulatory obligations; failure to obtain U.S. or international marketing approval; our product candidates may cause serious adverse side effects; inability to maintain our collaborations, or the failure of these collaborations; our reliance on third parties; effects of significant competition; the possibility of system failures or security breaches; risks relating to intellectual property; our ability to attract, retain and motivate qualified personnel, and risks relating to management transitions; significant costs as a result of operating as a public company; and the other important factors discussed under the caption “Risk Factors” in our most recently filed periodic report on Form 10-K or 10-Q and subsequent filings with the U.S. Securities and Exchange Commission (SEC) and our other filings with the SEC. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release. Contact:Elizabeth Pingpank Hickinehickin@zentalis.com860-463-0469

抗体药物偶联物

100 项与 TOP1靶向siRNA(北京键凯) 相关的药物交易

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