Carboplatin Research Articles

IGF2BP3-dependent N6-methyladenosine modification of USP49 promotes carboplatin resistance in retinoblastoma by enhancing autophagy via regulating the stabilization of SIRT1.

Retinoblastoma (RB) poses significant challenges in clinical management due to the emergence of resistance to conventional chemotherapeutic agents, particularly carboplatin (CBP). In this study, we investigated the molecular mechanisms underlying CBP resistance in RB, with a focus on the role of autophagy and the influence of ubiquitin-specific peptidase 49 (USP49). We observed upregulation of USP49 in RB tissues and cell lines, correlating with disease progression. Functional assays revealed that USP49 promoted aggressive proliferation and conferred CBP resistance in RB cells. Furthermore, USP49 accelerated tumor growth and induced CBP resistance in vivo. Mechanistically, we found that USP49 facilitated CBP resistance by promoting autophagy activation. In addition, we identified insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3)-mediated N6-methyladenosine (m6A) modification of USP49 as a regulatory mechanism, wherein IGF2BP3 upregulated USP49 expression in an m6A-dependent manner. Moreover, USP49 stabilized SIRT1, a protein associated with CBP resistance and autophagy, by inhibiting its ubiquitination and degradation. Rescue experiments confirmed the pivotal role of SIRT1 in USP49-mediated CBP resistance. Our findings delineate a novel molecular network involving USP49-mediated autophagy in promoting CBP resistance in RB, offering potential targets for therapeutic intervention to enhance treatment efficacy and improve outcomes for RB patients.

Carboplatin-loaded zeolitic imidazolate framework-8: Induction of antiproliferative activity and apoptosis in breast cancer cell.

The challenge with breast cancer is its ongoing high prevalence and difficulties in early detection and access to effective care. A solution lies in creating tailored metal-organic frameworks to encapsulate anticancer drugs, enabling precise and targeted treatment with less adverse effects and improved effectiveness. Zeolitic imidazolate framework-8 (ZIF-8) and carboplatin (CP)-loaded ZIF-8 were synthesized and characterized using various analytical techniques. High Resolution-transmission electron microscopy of ZIF-8 and CP@ZIF-8 indicates that the particles had a spherical shape and were nanosized. The drug release rate of CP is 98% under an acidic medium (pH 5.5) because of the dissolution of ZIF-8 into its coordinating ions, whereas 35% in a physiological medium (pH 7.4) with the addition of CP, the high porosity, and pore diameter of ZIF-8 decrease from 1243 to 1041m2/g. Breast cancer MCF-7 cells were shown greater IC50 in CP@ZIF-8 (15.01±3.03µg/mL) than free CP (34.98±4.25µg/mL) in an in vitro cytotoxicity assessment. The cytotoxicity of the CP@ZIF-8 against MCF-7 cells was studied using the methylthiazolyldiphenyl-tetrazolium bromide method. The morphological changes were examined using fluorescent staining (acridine orange-ethidium bromide and Hoechst 33258) methods. The comet assay assessed the DNA fragmentation (single-cell gel electrophoresis). The results from the study revealed that CP@ZIF-8 can be used in the treatment of breast cancer.

Combining Chemotherapy Agents and Autophagy Modulators for Enhanced Breast Cancer Cell Death

Purpose: Autophagy, governed by genes with dual roles in cell death and survival, plays a crucial role in cancer persistence. Arsenic trioxide (ATO), carboplatin (CP), and cyclophosphamide (CY) are used to treat various cancers. ATO impedes cell proliferation and triggers apoptosis in cancer cells. CP, a platinum-based drug, damages cancer cell DNA, while CY acts as an alkylating agent, disrupting cell proliferation. This study investigates the combined effects of ATO, CP, and CY on inducing apoptosis and modulating autophagy in triple-negative breast cancer (TNBC) cell lines, BT-20 and MDA-MB-231. Methods: The cytotoxic effects of ATO, CP, and CY, alone and in combination, were evaluated using the MTT assay on BT-20 and MDA-MB-231 cells. Apoptosis and cell cycle progression were analyzed by annexin-V FITC/PI staining and flow cytometry. Gene expression of autophagy- and apoptosis-related markers, including Beclin 1, LC3, caspase 3, and BCL2, was quantified using RT-PCR. Data were analyzed using GraphPad Prism 4.0 with one-way ANOVA followed by Dunnett's test. Results: The The combination of ATO, CP, and CY significantly reduced cell viability and enhanced apoptosis, evidenced by increased caspase-3 activity and reduced BCL2 expression. Cell cycle arrest in the G1 phase was observed, alongside elevated autophagy markers Beclin 1 and LC3. Conclusion: The combination of ATO, CP, and CY induces synergistic effects in promoting apoptosis and autophagy in TNBC cell lines. These findings suggest that this combination therapy could be a promising approach to enhancing treatment efficacy in aggressive breast cancers, offering new insights into potential therapeutic strategies.

MCL1 inhibitor S63845 delivered by follicle-stimulating hormone modified liposome potentiates carboplatin efficacy in ovarian cancer

Platinum resistance cause therapeutic failure and poor prognosis in ovarian cancer, and evasion of apoptosis is a critical factor in chemoresistance. A limited number of FDA-approved anticancer drugs directly target apoptotic pathways. Here, we discovered that MCL1, a critical anti-apoptotic protein, is amplified and associated with platinum resistance and survival in ovarian cancer, assisting in personalized treatment. We further identified S63845 through drug-based screening, the most potent MCL1 inhibitor, which efficiently enhanced carboplatin (CBP) sensitivity in various ovarian cancer models, including primary ovarian cancer cells, orthotopic ovarian cancer, peritoneal metastasis, and human patient-derived xenograft (PDX) models. Mechanistically, S63845 competitively binds to MCL1, disrupts the binding of apoptosis effector (BAK and BAX) or pro-apoptotic BH3 protein (BIM) to MCL1 respectively, and eventually enhances CBP-induced apoptosis.To promote the clinical transformation of S63845, we developed follicle-stimulating hormone-modified liposome nanoparticles (S63845@Lipo-FSH) to enhance stability, membrane penetration, and tumor-targeting capabilities. S63845@Lipo-FSH exhibits a superior therapeutic efficacy and tumor targeting compared to free S63845, even when the dose of S63845 is reduced to one-fifth. Overall, targeting MCL1 by S63845@Lipo-FSH enhances CBP efficiency in ovarian cancer, with safety and efficacy, suggesting that this strategy is effective and promising for clinical application.

1813TiP Debio 0123, a highly selective WEE1 inhibitor, combined with carboplatin (CP) and etoposide (ETOP) in patients (pts) with small cell lung cancer (SCLC) that progressed after platinum-based therapy: A phase I dose escalation and expansion study

1813TiP Debio 0123, a highly selective WEE1 inhibitor, combined with carboplatin (CP) and etoposide (ETOP) in patients (pts) with small cell lung cancer (SCLC) that progressed after platinum-based therapy: A phase I dose escalation and expansion study

630P Debio 0123 + carboplatin (CP) for patients (pts) with advanced solid tumors: Safety, preliminary efficacy and determination of recommended phase II dose (RP2D)

630P Debio 0123 + carboplatin (CP) for patients (pts) with advanced solid tumors: Safety, preliminary efficacy and determination of recommended phase II dose (RP2D)

The Synthesis and Pharmacokinetics of a Novel Liver-Targeting Cholic Acid-Conjugated Carboplatin in Rats

A novel cholic acid-conjugated carboplatin (CP-CA) is developed as a liver-targeting prodrug of carboplatin (CP) for liver cancer. Instead of using CP as a raw material, CP-CA was synthesized simultaneously. This paper is focused on the comparison of CP-CA and CP with respect to their pharmacokinetic (PK) and tissue distribution profiles in rats after their intravenous administration. Additionally, their uptake by human liver tumor cell Huh7 and normal human liver cell HL7702 are investigated. The inductively coupled plasma mass spectrometry (ICP-MS) method is applied for the determination of platinum in plasma, tissues, and cells. The PK results show that both the AUC0–t and AUC0–∞ data on Pt for CP-CA are significantly higher than those for CP (p < 0.01), indicating that the plasma exposure of CP-CA is significantly higher than that of CP. The CL1, Vd1, and Vd2 data on Pt for CP-CA are significantly lower than those for CP (p < 0.01), while the MRT0-t is significantly higher (p < 0.01), which is possibly related to a higher PPBR, and can strongly support the higher AUC0–t and AUC0–∞ of Pt for CP-CA compared to for CP. The tissue distribution results show that CP-CA is mainly distributed and accumulated in the liver after its intravenous administration to rats, revealing its liver-targeting profile. Compared to CP, CP-CA is more easily taken up by human liver cancer cells and normal human liver cells. The results suggest that CP-CA has a potential for further development as a new prodrug specific to liver cancer.

Development of receptor-targeted and pH-responsive zeolitic imidazole framework-90 nanoplatform for anti-ovarian cancer

The covalent functionalization of the zeolitic imidazolate framework (ZIF) is rapidly progressing and is being exploited as a nanoplatform for antitumor drug delivery to improve tumor targeting and drug release. Here, a novel nanoplatform strategy was developed by encapsulating Carboplatin (CBP) in ZIF-90 nanospheres (NPs) to obtain CBP@ZIF-90 NPs and then, modifying folate-terminated methoxypoly(ethylene glycol) (FA-PEG-NH2) on the aldehyde group of ZIF-90 to form CBP@ZIF-90-NPF NPs with acid-sensitive Schiff base bond. The research results indicate that the yield of ZIF-90 was 72.77 ± 0.27 %, and the encapsulation efficiency and the loading content of CBP@ZIF-90 were 45.22 ± 0.49 % and 24.65 ± 0.34 %, respectively. The size of CBP@ZIF-90-NPF was 107.7 ± 1.7 nm in monodispersity with a single crystalline dodecahedral structure. Furthermore, the in vitro release behavior study revealed the sustained-release and the pH-responsive dissociation properties of the NPs. Only 6.84 % of CBP was released from the nanocarrier under physiological pH conditions for 48 h, while the release from the tumor microenvironment was 92.89 %. In addition, the cellular uptake result clearly showed that most of the FA-PEG-NH2 modified NPs exhibited specific selectivity in tumor cell nuclei. Finally, the cell counting kit-8 (CCK8) assay based on human ovarian cancer cell line (OVCAR-3) and human normal ovarian epithelial (IOSE-80) cell line obviously indicated that the ZIF-90 NPs had good biocompatibility and minimal cytotoxicity, as well as the high inhibition efficiency of the CBP@ZIF-90-NPF NPs meant that a much higher amount of CBP was transferred into the folate receptor (FR)-overexpressed ovarian cancer cells via FR mediated endocytosis. These results suggest that ZIF-90-NPF NPs could be an ideal targeted drug delivery vehicle for CBP, serving as a promising strategy for ovarian cancer treatment.

First-in-human phase I trial of the oral first-in-class ubiquitin specific peptidase 1 (USP1) inhibitor KSQ-4279 (KSQi), given as single agent (SA) and in combination with olaparib (OLA) or carboplatin (CARBO) in patients (pts) with advanced solid tumors, enriched for deleterious homologous recombination repair (HRR) mutations.

3005 Background: USP1 is a deubiquitinase that regulates DNA damage response pathways, such as Translesion Synthesis and Fanconi Anemia pathways. KSQi is a potent, selective small molecule inhibitor of USP1 with anti-proliferative activity in tumors with HRR mutations. The combination of KSQi and PARP inhibitors (PARPi) showed strong synergy in Ovarian and TNBC PDX models, supporting this clinical trial. Methods: This is a 2-part study: Part 1 dose escalation using a BOIN design explored safety, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary anti-tumor activity of KSQi as SA (Arm 1) and in combination with OLA at 200 mg BID (Arm 2) or CARBO at AUC 4 (Arm 3) to determine the MTD and/or recommended dose for expansion (RDE). Part 2 will assess efficacy and safety of the combinations in expansion cohorts. Results: As of Jan 4, 2024, 64 pts (19m/45f; median age 63 y) received KSQi 100 - 1250 mg; Arm 1: 100 mg (3 pts), 150 (3), 200 (4), 300 (6), 450 (5), 650 (9), 900 (7) and 1250 (5); Arm 2: 200 (5), 450 (5) and 900 (5); Arm 3: 200 (3) and 450 (4). Median number of prior therapies was 5, 4 and 3 for Arm 1, 2 and 3, respectively. 29% had prior PARPi in Arm 1, 53% in Arm 2, and 71% in Arm 3. All pts in Arms 2 and 3 had tumors with deleterious HRR mutations. Most common treatment-emergent adverse events (TEAE) were anemia (36%), increased creatinine (33%) as SA, and anemia in combination with OLA (87%) and CARBO (71%). The most common G3+ TEAEs were hyponatremia (12%) as SA and anemia in combination with OLA (73%) and CARBO (29%). DLTs (n = 3) were G3 maculopapular rash at 1250 mg (Arm 1) and G3 WBC decrease at 200 mg, G3 anemia at 450 mg (Arm 2). 30% (19/64) of pts had an interruption in KSQi dosing and 1 (1.6%) discontinued treatment. PK AUC and Cmax increased almost dose-proportionally up to 650 mg. A preliminary review of OLA concentrations following co-administration with KSQi showed no significant impact of OLA at C2D1. Ubiquitinated PCNA induction was observed in paired tumor biopsies from pts receiving KSQi, supporting intra-tumoral USP1 inhibition. A RECIST PR was observed in a fallopian tube cancer pt lasting 7 weeks and SD in 9 pts treated with SA KSQi; best response in combination with OLA was SD in 6 pts and 2 SD with CARBO. Disease control rate at 16 weeks was 28% (Arm 1), 40% (Arm 2) and 29% (Arm 3). Conclusions: KSQi is a first-in-class USP1 inhibitor with an acceptable safety profile as SA and in combination. An MTD was not reached in any Arms. PD results support the mechanism of action of USP1 inhibition. The RDE will be determined in additional back-fill cohorts. Clinical trial information: NCT05240898 .

Impact of carboplatin and cisplatin shortages on treatment patterns in patients with metastatic solid tumors.

11149 Background: The United States experienced cisplatin (CP) and carboplatin (CB) shortages in 2023, leading to potential rationing or switching to alternative therapies in multiple cancers. Using a US nationwide, real-world oncology dataset, we assessed changes in the use of CP and CB in 7 cancers during the shortage period. Methods: All patients (pts) from the Flatiron Health electronic health record-derived de-identified database (~280 cancer clinics, ~800 sites of care) with a machine learning-extracted metastatic (met) diagnosis of a cancer of interest between March 2022 and June 2023 and evidence of first-line (1L) therapy, were selected. Pts with multiple primaries were excluded. Platinum of interest was identified based on frequency of pre-period 1L use for a given cancer. The pre-period was June 2022 through first month of reported shortage (February 2023 for CP; April 2023 for CB); data cutoff was June 2023. Clinical characteristics of platinum-treated pts stratified by pre- vs post-period by disease were assessed. 1L platinum utilization rates (UR), calculated as the proportion of 1L-treated pts initiating CB/CP within 30 days of met diagnosis, were plotted by month. Cohort-level impact was evaluated with an interrupted time series analysis—overall and stratified by practice type, practice size, and socioeconomic status (SES). Multiple testing was controlled using the Benjamini-Hochberg procedure. Results: 10,983 pts received 1L therapy in the study period. Monthly platinum UR were stable across diseases in the pre-period. However, there was a significant post-period decrease in CB usage for non-small cell lung (NSCLC) and endometrial cancers (EC), and a decreasing trend in UR for CB in bladder (BC), ovarian (OC), and small cell lung cancers (SCLC). We also observed a decreasing trend in CP usage for cholangiocarcinoma (CC). Post-period monthly UR were stable for CB and CP in head and neck cancer (HNC), and for CP in BC. Odds ratios (OR) representing the month-over-month change in the odds of receiving platinum therapy during both pre- and post-periods are shown (table). OR trends varied by practice type and disease; no notable trends were seen by practice size or SES. UR with additional follow-up times will be presented. Conclusions: We observed decreased platinum use across multiple cancers during the shortage period, most notably for met NSCLC and EC, suggesting shortages led oncologists to seek alternatives to standard 1L platinum-based regimens. Further study of how treatment changes due to platinum shortages impacted pt outcomes is warranted. [Table: see text]

Weekly paclitaxel (P), carboplatin (CP) plus pembrolizumab (PMB) as first-line treatment of recurrent or metastatic (R/M) or locally very advanced (LVA) head and neck squamous cell carcinoma (HNSCC): A retrospective study in 39 patients (pts).

e18018 Background: Since the results of the KN-048 trial, the combination of platinum/5FU plus PMB has become the standard of care (SOC) for R/M HNSCC pts. The KN-B10 study shows that 5FU can be replaced by P with a favorable response rate and toxicity profile. Weekly use of P reduces hematologic toxicity and increases dose-intensity. Methods: We retrospectively reviewed all records of patients with R/M or LVA (T4b and/or N3b) HNSCC, ECOG-PS 0 to 2, PDL1 CPS ≥ 1, treated in first-line with weekly P (80 mg/m2) and CP (AUC 2: maximum total dose of 250 mg and systematic G-CSF at D3 and D4) for up to 12 infusions plus PMB every 3 weeks for up to 35 administrations. Results: From July 2020 to April 2023, 39 pts (median age 63 years, 74% male, 18% PS2) were treated. Primary tumors: oropharynx 44%, larynx 23%, hypopharynx 18% and oral cavity 15%. Disease setting: LVA 20%, local recurrence in irradiated area 54%, local recurrence and distant metastases 10% distant metastases only15%. With a median follow-up of 19 months (m), median Overall Survival (mOS) was 17.2 m (95%CI: 10.8-NR). 31/39 (79%) pts achieved an objective response (OR): 7 CR and 24 PR. For the 8 LVA pts, all achieved an OR, with a median Event Free Survival of 10 m (95%CI: 6.27-NR): the 4 progression-free pts (8.6 m+ to 25 m+) were treated with radiotherapy after neoadjuvant immuno-chemotherapy. For the 31 R/M pts, ECOG-PS was a significant prognostic factor of OS, mOS: 19.3 m (95%CI: 14.4-NR) for ECOG-PS 0-1 pts vs. 10.3 m (95%CI: 5.4-13.9) for ECOG-PS 2 pts (p = 0.02). For R/M pts, median Progression Free survival was 6.9 m (95%CI: 4.4-8.6) and the ORR was 74%, with a median duration of response of 6.5 m (95%CI: 3.13-8.56). Toxicity was manageable, with 20 (51%) pts experiencing at least one grade 3-4 adverse event: hematologic 18% (including one febrile neutropenia), infection 5%, neuropathy 8%, diarrhea 8%, infusion reaction 8%, electrolyte disturbances 8%, renal failure 3% and no toxic deaths. Conclusions: The combination of weekly P and CP plus PMB produces a high ORR and increased OS consistent with the results of the Frail-Immune study (J. Fayette ASCO 2023). This regimen deserves further consideration not only in the R/M setting, but also in the neoadjuvant setting for locally advanced patients.

Nanoscale ZIF-8 as an efficient carboplatin carrier for targeted cancer therapy

Cancer is a leading cause of death worldwide and is becoming more prevalent. Carboplatin (CBP) is an anti-cancer medication from the platinum group of substances that are frequently employed in chemotherapy, and it is an active anti-cancer agent. However, the adverse effects of platinum medications, including its lack of selectivity, significant systemic toxicity, and drug resistance, limit its usage. The zeolitic imidazolate framework-8 (ZIF-8) has gained global biomedical interest for its high drug loading capacity and controlled release into target cells. It is synthesized using a non-solvothermal method and has shown the capacity to regulate and enhance the selectivity of cancer cells. A rapid high-performance liquid chromatography equipped with photodiode array detector (HPLC-PDA) method was used to measure the CBP loading capacity on ZIF-8, and the result was found to be 0.066 mg mg−1. ZIF-8 could effectively protect CBP in the in vitro release test in the physiological environment (pH 7.4). When pH 5.5 was reached, ZIF-8 served as a pH-resposive nanocarrier, leading to gradual CPB release. Studies on the in vitro cytotoxicity of CBP showedthat the IC50 of CBP for the lung cancer cell line was significantly lowered upon encapsulation of CBP in nanoparticles.

Co-delivery of carboplatin and doxorubicin using ZIF-8 coated chitosan-poly(N-isopropyl acrylamide) nanoparticles through a dual pH/thermo responsive strategy to breast cancer cells

A dual pH/temperature sensitive core-shell nanoformulation has been developed based on ZIF-8 coated with chitosan-poly(N-isopropyl acrylamide) (CS-PNIPAAm) for co-delivery of doxorubicin (DOX) and carboplatin (CBP) in breast cancer cells. The resulting nanoparticles (NPs) had particle sizes around 200 nm and a zeta potential of about +30 mV. The CBP and DOX loading contents in the final NPs were 11.6 % and 55.54 %, respectively. NPs showed a pH and thermoresponsive drug release profile with a sustained prolonged release under physiological conditions. The in vitro cytotoxicity experiments showed a significant synergism of CBP and DOX to induce the IC50 of 1.96 μg/mL in MCF-7 cells and 4.54 μg/mL in MDA-MB-231 cells. Also, the final NPs were safer than free DOX and CBP on normal cells. The in vitro study confirmed the higher potency of the designed NPs in combination therapy against breast cancer cells with lower side effects than free drugs.

Electrochemical Sensing Device for Carboplatin Monitoring in Proof-of-Concept Drug Delivery Nanosystems.

(1) Background: Carboplatin (CBP) is a chemotherapeutic drug widely used in the treatment of a variety of cancers. Despite its efficiency, CBP is associated with side effects that greatly limit its clinical use. To mitigate these effects, CBP can be encapsulated in targeted delivery systems, such as liposomes. Ensuring the adequate loading and release of CBP from these carriers requires strict control in pharmaceutical formulation development, demanding modern, rapid, and robust analytical methods. The aim of this study was the development of a sensor for the fast and accurate quantification of CBP and its application on proof-of-concept CBP-loaded nanosomes. (2) Methods: Screen-printed electrodes were obtained in-lab and the electrochemical behavior of CBP was tested on the obtained electrodes. (3) Results: The in-lab screen-printed electrodes demonstrated superior properties compared to commercial ones. The novel sensors demonstrated accurate detection of CBP on a dynamic range from 5 to 500 μg/mL (13.5-1350 μM). The method was successfully applied on CBP loaded and released from nanosomes, with strong correlations with a spectrophotometric method used as control. (4) Conclusions: This study demonstrates the viability of electrochemical techniques as alternative options during the initial phases of pharmaceutical formulation development.

Extracellular vesicles of Bifidobacterium longum reverse the acquired carboplatin resistance in ovarian cancer cells via p53 phosphorylation on Ser15.

We previously found that the relative abundance of Bifidobacterium was increased after chemotherapy; however, the role of Bifidobacterium longum in chemotherapeutic drug resistance in ovarian cancer (OVC) remains unclear. This study aimed to understand the potential effects and mechanism of B. longum extracellular vesicles (B. longum-EVs) on carboplatin (CBP) resistance in OVC. Eight normal and 11 ovarian tissues were collected and the expression of B. longum genomic DNA and its association with acquired CBP resistance in OVC patients was determined. After isolating EVs by ultracentrifugation from B. longum (ATCC 15707), CBP-resistant A2780 cells were treated with PBS, CBP, B. longum-EVs, or CBP + B. longum-EVs, and subsequently analyzed by CCK-8, Edu staining, Annexin V/PI double staining, wound healing, and Transwell assays to detect cell viability, proliferation, apoptosis, migration, and invasion, respectively. MRP1, ATP7A, ATP7B, and p53 expression as well as p53 phosphorylation were measured by western blot analysis. S15A mutation of p53 was assessed to examine the potential role of p53 Ser15 phosphorylation in CBP-resistant OVC. B. longum levels were elevated and positively associated with CBP resistance in OVC patients. Only high concentrations of B. longum-EVs attenuated A2780 cell proliferation, apoptosis, migration, and invasion. B. longum-EVs exposure significantly enhanced the sensitivity of CBP-resistant A2780 cells to CBP and decreased the expression of drug resistance-related proteins. The effect of B. longum-EVs on reversing CBP resistance was completely inhibited by S15A mutation of p53. B. longum-EVs enhanced the sensitivity of OVC cells to CBP through p53 phosphorylation on Ser15.

The Ability of Clinically Relevant Chemotherapeutics to Induce Immunogenic Cell Death in Squamous Cell Carcinoma.

Immunogenic cell death (ICD) is a crucial mechanism for triggering the adaptive immune response in cancer patients. Damage-associated molecular patterns (DAMPs) are critical factors in the detection of ICD. Chemotherapeutic drugs can cause ICD and the release of DAMPs. The aim of this study was to assess the potential for paclitaxel and platinum-based chemotherapy regimens to induce ICD in squamous cell carcinoma (SCC) cell lines. In addition, we examined the immunostimulatory effects of clinically relevant chemotherapeutic regimens utilized in the treatment of SCC. We screened for differentially expressed ICD markers in the supernatants of three SCC cell lines following treatment with various chemotherapeutic agents. The ICD markers included Adenosine Triphosphate (ATP), Calreticulin (CRT), Annexin A1 (ANXA 1), High Mobility Group Protein B1 (HMGB1), and Heat Shock Protein 70 (HSP70). A vaccination assay was also employed in C57BL/6J mice to validate our in vitro findings. Lastly, the levels of CRT and HMGB1 were evaluated in Serum samples from SCC patients. Addition of the chemotherapy drugs cisplatin (DDP), carboplatin (CBP), nedaplatin (NDP), oxaliplatin (OXA) and docetaxel (DOC) increased the release of ICD markers in two of the SCC cell lines. Furthermore, mice that received vaccinations with cervical cancer cells treated with DDP, CBP, NDP, OXA, or DOC remained tumor-free. Although CBP induced the release of ICD-associated molecules in vitro, it did not prevent tumor growth at the vaccination site in 40% of mice. In addition, both in vitro and in vivo results showed that paclitaxel (TAX) and LBP did not induce ICD in SCC cells. The present findings suggest that chemotherapeutic agents can induce an adjuvant effect leading to the extracellular release of DAMPs. Of the agents tested here, DDP, CBP, NDP, OXA and DOC had the ability to act as inducers of ICD.

Abstract 945: In vivo anti-tumor activity of onvansertib, a PLK1 inhibitor, combined with gemcitabine or carboplatin in platinum- resistant ovarian carcinoma patient-derived xenograft models

Abstract Background: The standard treatment for high grade ovarian carcinoma (HGOC) is cytoreductive surgery followed by a platinum based therapy. Despite an initial high rate of complete remission, most of the patients relapse with a platinum resistant disease. Patients with resistant tumors have few options, including monotherapy with gemcitabine, and new effective therapeutic alternatives are needed. The Polo-like kinase 1 (PLK1) is a master regulator of mitosis and recent evidences suggest its role in interfering with several DNA repair mechanisms. We investigated the effect of onvansertib (ONVA), a highly selective ATP-competitor PLK1 inhibitor, in combination with carboplatin (CARBO) and gemcitabine (GEM) in platinum-resistant HGOC patient-derived xenografts (PDXs). Methods: The combination of ONVA with either CARBO or GEM was investigated in two platinum-resistant HGOC PDXs, one intrinsically resistant to platinum (MNHOC#315), the other made resistant after repeated in vivo treatments with cisplatin (MNHOC#266R). Tumors were subcutaneously (s.c.; MNHOC#315) or orthotopically (i.p.; MNHOC#266R) transplanted in nude mice, mice were treated for 4 weeks with vehicle, single agents or drug combinations and followed for tumor growth (s.c. model) and survival. Results: CARBO- and GEM-ONVA combinations were well tolerated, with a maximum body weight loss of 6.6%. Both combinations showed strong anti-tumor activities in the two tested models. In MNHOC#315 PDX, CARBO- and GEM-ONVA combinations caused a tumor stabilization that extended beyond the dosing period and resulted in a higher tumor growth inhibition as compared to vehicle and single agents treated mice. In i.p. MNHOC#266R PDX, single agents were inactive, while a statistically significant increase in survival was observed in CARBO/ONVA and in GEM/ONVA treated mice as compared to vehicle treated mice, with a 6.6- and 7-fold increase in mean survival time, respectively. Pharmacodynamic studies are ongoing to decipher the mechanisms underlying the synergic effects of both combinations. Conclusions: The combinations of ONVA with either CARBO or GEM showed potent anti-tumor activities in two platinum-resistant HGOC PDXs. Additional studies in other HGOC platinum-resistant models, both in vivo and in vitro, as well pharmacodynamic studies are ongoing to validate these results and to get insights in the mechanisms underlying their efficacy. Citation Format: Michela Chiappa, Federica Guffanti, Ilaria Mengoli, Maya Ridinger, Giovanna Damia. In vivo anti-tumor activity of onvansertib, a PLK1 inhibitor, combined with gemcitabine or carboplatin in platinum- resistant ovarian carcinoma patient-derived xenograft models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 945.

Small extracellular vesicles loaded with carboplatin effectively enhance the cytotoxicity of drug-resistant cells from Y79 cells-in vitro

Drug resistance (DR) is one of the challenges in treating retinoblastoma (Rb) that warrants novel approaches. With the emerging evidence on the role of small extracellular vesicles (sEVs) as a drug-delivery carrier system, in this study, we derived the drug-resistant (DR) clones of Y79 cells and evaluated the efficacy of sEVs-loaded with carboplatin (sEVs-CPT) to reverse the chemoresistance. Drug-resistant clones of Y79 cells (DR-Y79) were systematically developed through sequential exposure to carboplatin (CPT), showcasing a sixfold increase in inhibitory concentration when compared to parental Y79 cells (IC50: 41.4 µg/mL and 6.2 µg/mL) (P<0.0001). These DR-Y79 cells show higher expression of ABCG2 and higher expression of DR genes than parental Y79 cells (P<0.0001). The sEVs were isolated from the conditioned media of Y79 cells using ultracentrifugation (UC) and characterized. Further, the sEVs were loaded with CPT and achieved higher encapsulation efficiency at one hour, and drug release of sEVs-CPT was highest at ∼80% at pH 5.0. The cytotoxicity of sEVs-CPT on Y79 cells and DR-Y79 was higher when compared to the CPT (IC50: 3.5 µg/mL vs 6.2 µg/mL; 23.1 µg/mL vs 41.2 µg/mL) (p<0.0001). This study demonstrates that sequential exposure to CPT generates DR clones of Y79 cells, which could serve as an appropriate model to evaluate the efficacy of drugs. The sEVs-CPT were highly effective in enhancing cytotoxicity in DR-Y79 cells, and appear to hold promise as a novel complimentary drug delivery system.

Abstract A066: The cytotoxic effects of oxaliplatin and 5-fluorouracil against low-grade serous ovarian cancer cells

Abstract A066: The cytotoxic effects of oxaliplatin and 5-fluorouracil against low-grade serous ovarian cancer cells

Expression of molecular markers and synergistic anticancer effects of chemotherapy with antimicrobial peptides on glioblastoma cells.

Glioblastoma multiforme (GBM) is the most aggressive and fatal malignant primary brain tumor. The enhancement of the survival rate for glioma patients remains limited, even with the utilization of a combined treatment approach involving surgery, radiotherapy, and chemotherapy. This study was designed to assess the expression of IDH1, TP53, EGFR, Ki-67, GFAP, H3K27M, MGMT, VEGF, NOS, CD99, and ATRX in glioblastoma tissue from 11 patients. We investigated the anticancer impact and combined effects of cathelicidin (LL-37), protegrin-1 (PG-1), with chemotherapy-temozolomide (TMZ), doxorubicin (DOX), carboplatin (CB), cisplatin (CPL), and etoposide (ETO) in primary GBM cells. In addition, we examined the effect of LL-37, PG-1 on normal human fibroblasts and in the C6/Wistar rat intracerebral glioma model. For this study, 11 cases of glioblastoma were evaluated immunohistochemically for IDH1, TP53, EGFR, Ki-67, GFAP, H3K27M, MGMT, VEGF, NOS, CD99, and ATRX. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to study cells viability and to determine cytotoxic effects of LL-37, PG-1 and their combination with chemotherapy in primary GBM cells. Synergism or antagonism was determined using combination index (CI) method. Finally, we established C6 glioblastoma model in Wistar rats to investigate the antitumor activity. Peptides showed a strong cytotoxic effect on primary GBM cells in the MTT test (IC50 2-16 and 1-32μM) compared to chemotherapy. The dual-drug combinations of LL-37 + DOX, LL-37 + CB (CI 0.46-0.75) and PG-1 + DOX, PG-1 + CB, PG-1 + TMZ (CI 0.11-0.77), demonstrated a synergism in primary GBM cells. In rat C6 intracerebral GBM model, survival of rats in experimental group (66.75 ± 12.6days) was prolonged compared with that in control cohort (26.2 ± 2.66days, p = 0.0008). After LL-37 treatment, experimental group rats showed significantly lower tumor volumes (31.00 ± 8.8 mm3) and weight (49.4 ± 13.3mg) compared with control group rats (153.8 ± 43.53mg, p = 0.038; 82.50 ± 7.60 mm3, respectively). The combination of antimicrobial peptides and chemical drugs enhances the cytotoxicity of chemotherapy and exerts synergistic antitumor effects in primary GBM cells. Moreover, in vivo study provided the first evidence that LL-37 could effectively inhibit brain tumor growth in rat C6 intracerebral GBM model. These results suggested a significant strategy for proposing a promising therapy for the treatment of GBM.