Baseline extracellular vesicle TGF-ß is a predictive biomarker for response to immune checkpoint inhibitors and survival in non-small cell lung cancer.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) are an effective therapeutic strategy, improving the survival of patients with lung cancer compared with conventional treatments. However, novel predictive biomarkers are needed to stratify which patients derive clinical benefit because the currently used and highly heterogenic histological PD-L1 has shown low accuracy. Liquid biopsy is the analysis of biomarkers in body fluids and represents a minimally invasive tool that can be used to monitor tumor evolution and treatment effects, potentially reducing biases associated with tumor heterogeneity associated with tissue biopsies. In this context, cytokines, such as transforming growth factor-ß (TGF-ß), can be found free in circulation in the blood and packaged into extracellular vesicles (EVs), which have a specific delivery tropism and can affect in tumor/immune system interaction. TGF-ß is an immunosuppressive cytokine that plays a crucial role in tumor immune escape, treatment resistance, and metastasis. Thus, we aimed to evaluate the predictive value of circulating and EV TGF-ß in patients with non-small-cell lung cancer receiving ICIs. METHODS: Plasma samples were collected in 33 patients with advanced non-small-cell lung cancer before and during treatment with ICIs. EV were isolated from plasma by serial ultracentrifugation methods and circulating and EV TGF-ß expression levels were evaluated by enzyme-linked immunosorbent assay. RESULTS: Baseline high expression of TGF-ß in EVs was associated with nonresponse to ICIs as well as shorter progression-free survival and overall survival, outperforming circulating TGF-ß levels and tissue PD-L1 as a predictive biomarker. CONCLUSION: If validated, EV TGF-ß could be used to improve patient stratification, increasing the effectiveness of treatment with ICIs and potentially informing combinatory treatments with TGF-ß blockade. PLAIN LANGUAGE SUMMARY: Treatment with immune-checkpoint inhibitors (ICIs) has improved the survival of some patients with lung cancer. However, the majority of patients do not benefit from this treatment, making it essential to develop more reliable biomarkers to identify patients most likely to benefit. In this pilot study, the expression of transforming growth factor-ß (TGF-ß) in blood circulation and in extracellular vesicles was analyzed. The levels of extracellular vesicle TGF-ß before treatment were able to determine which patients would benefit from treatment with ICIs and have a longer survival with higher accuracy than circulating TGF-ß and tissue PD-L1, which is the currently used biomarker in clinical practice.

Regulation of cisplatin-resistant head and neck squamous cell carcinoma by the SRC/ETS-1 signaling pathway.

BACKGROUND: We investigated the role of the ETS-1 transcription factor in Head and Neck Squamous Cell Carcinoma (HNSCC) in multiple cisplatin-resistant HNSCC cell lines. METHODS: We examined its molecular link with SRC and MEK/ERK pathways and determined the efficacy of either MEK/ERK inhibitor PD0325901 or SRC inhibitor Dasatinib on cisplatin-resistant HNSCC inhibition. RESULTS: We found that ETS-1 protein expression levels in a majority of cisplatin-resistant HNSCC cell types were higher than those in their parental cisplatin sensitive partners. High ETS-1 expression was also found in patient-derived, cisplatin-resistant HNSCC cells. While ETS-1 knockdown inhibited cell proliferation, migration, and invasion, it could still re-sensitize cells to cisplatin treatment. Interestingly, previous studies have shown that MER/ERK pathways could regulate ETS-1 through its phosphorylation at threonine 38 (T38). Although almost all cisplatin-resistant HNSCC cells we tested showed higher ETS-1 phosphorylation levels at T38, we found that inhibition of MEK/ERK pathways with the MEK inhibitor PD0325901 did not block this phosphorylation. In addition, treatment of cisplatin-resistant HNSCC cells with the MEK inhibitor completely blocked ERK phosphorylation but did not re-sensitize cells to cisplatin treatment. Furthermore, we found that, consistent with ETS-1 increase, SRC phosphorylation dramatically increased in cisplatin-resistant HNSCC, and treatment of cells with the SRC inhibitor, Dasatinib, blocked SRC phosphorylation and decreased ETS-1 expression. Importantly, we showed that Dasatinib, as a single agent, significantly suppressed cell proliferation, migration, and invasion, in addition to survival. CONCLUSIONS: Our results demonstrate that the SRC/ETS-1 pathway plays a crucial role and could be a key therapeutic target in cisplatin-resistant HNSCC treatment.

Synthesis, characterization and antineoplastic activity of bis-aziridinyl dimeric naphthoquinone - A novel class of compounds with potent activity against acute myeloid leukemia cells.

The synthesis, characterization and antileukemic activity of rationally designed amino dimeric naphthoquinone (BiQ) possessing aziridine as alkylating moiety is described. Bis-aziridinyl BiQ decreased proliferation of acute myeloid leukemia (AML) cell lines and primary cells from patients, and exhibited potent (nanomolar) inhibition of colony formation and overall cell survival in AML cells. Effective production of reactive oxygen species (ROS) and double stranded DNA breaks (DSB) induced by bis-aziridinyl BiQ is reported. Bis-dimethylamine BiQ, as the isostere of bis-aziridinyl BiQ but without the alkylating moiety did not show as potent anti-AML activity. Systemic administration of bis-aziridinyl BiQ was well tolerated in NSG mice.

Structure-based drug design and potent anti-cancer activity of tricyclic 5:7:5-fused diimidazo[4,5-d:4',5'-f][1,3]diazepines.

Judicial structural modifications of 5:7-fused ring-expanded nucleosides (RENs), based on molecular modeling studies with one of its known targets, human RNA helicase (hDDX3), led to the lead, novel, 5:7-5-fused tricyclic heterocycle (1). The latter exhibited promising broad-spectrum in vitro anti-cancer activity against a number of cancer cell lines screened. This paper describes our systematic, albeit limited, structure-activity relationship (SAR) studies on this lead compound, which produced a number of analogs with broad-spectrum in vitro anti-cancer activities against lung, breast, prostate, and ovarian cancer cell lines, in particular compounds 15i, 15j, 15m and 15n which showed IC(50) values in submicromolar to micromolar range, and are worthy of further explorations. The SAR data also enabled us to propose a tentative SAR model for future SAR efforts for ultimate realization of optimally active and minimally toxic anti-cancer compounds based on the diimidazo[4,5-d:4',5'-f][1,3]diazepine structural skeleton of the lead compound 1.

Equipotent doses of daunorubicin and idarubicin for AML: a meta-analysis of clinical trials versus in vitro estimation.

In the treatment of acute myeloid leukemia (AML), the "7 + 3"-based strategy, combining cytarabine 100-200 mg/m2 for 7 days with an anthracycline for 3 days, remains the standard of care for younger and medically fit patients. Daunorubicin (DNR) and idarubicin (IDA) are the two anthracyclines most commonly used. DNR and IDA are used interchangeably with different conversion factors, as there is no high-level evidence on the equipotency of these two agents for AML treatment. To determine the equipotent doses of DNR and IDA, we first systematically reviewed studies directly comparing the clinical outcomes of AML induction therapy utilizing DNR and IDA. We found 15 articles that met our inclusion criteria and compared time-to-event survival end points as well as complete remission rates post-induction. The DNR:IDA equipotency ratio was estimated at 5.90 with 95% confidence interval (CI) 1.7-20.7. To validate the estimate from our meta-analysis biologically, we conducted in vitro tests comparing anti-AML activity of DNR and IDA against six AML cell lines and two primary AML cells from patients with different cytogenetic and molecular characteristics. Based on these in vitro data, the equipotency dose ratio between DNR and IDA was 4.06 with 95% CI 3.64-4.49. Combining the estimates from the meta-analysis and the in vitro data using inverse-variance weighting, the current best estimate of the DNR:IDA equipotent ratio is 4.1 with 95% CI 3.9-4.3. This estimate, however, is largely driven by the in vitro chemo-sensitivity data. Given clinical studies demonstrating the safety of IDA at higher doses, our work implies that dose intensification of IDA could be investigated in future clinical trials in AML.

Potently inhibiting cancer cell migration with novel 3H-pyrazolo[4,3-f]quinoline boronic acid ROCK inhibitors.

Rho-associated protein kinases (ROCKs) are ubiquitously expressed in most adult tissues, and are involved in modulating the cytoskeleton, protein synthesis and degradation pathways, synaptic function, and autophagy to list a few. A few ROCK inhibitors, such as fasudil and netarsudil, are approved for clinical use. Here we present a new ROCK inhibitor, boronic acid containing HSD1590, which is more potent than netarsudil at binding to or inhibiting ROCK enzymatic activities. This compound exhibits single digit nanomolar binding to ROCK (Kds < 2 nM) and subnanomolar enzymatic inhibition profile (ROCK2 IC50 is 0.5 nM for HSD1590. Netarsudil, an FDA-approved drug, inhibited ROCK2 with IC50 = 11 nM under similar conditions). Whereas netarsudil was cytotoxic to breast cancer cell line, MDA-MB-231 (greater than 80% growth inhibition at concentrations greater than 5 µM), HSD1590 displayed low cytotoxicity to MDA-MB-231. Interestingly, at 1 µM HSD1590 inhibited the migration of MDA-MB-231 whereas netarsudil did not.

Amino alkynylisoquinoline and alkynylnaphthyridine compounds potently inhibit acute myeloid leukemia proliferation in mice.

BACKGROUND: Acute myeloid leukemia (AML) remains one of the most lethal, rarely cured cancers, despite decades of active development of AML therapeutics. Currently, the 5-year survival of AML patients is about 30% and for elderly patients, the rate drops to <10%. About 30% of AML patients harbor an activating mutation in the tyrosine kinase domain (TKD) of Fms-Like Tyrosine kinase 3 (FLT3) or a FLT3 internal tandem duplication (FLT3-ITD). Inhibitors of FLT3, such as Rydapt that was recently approved by the FDA, have shown good initial response but patients often relapse due to secondary mutations in the FLT3 TKD, like D835Y and F691 L mutations. METHODS: Alkynyl aminoisoquinoline and naphthyridine compounds were synthesized via Sonogashira coupling. The compounds were evaluated for their in vitro and in vivo effects on leukemia growth. FINDINGS: The compounds inhibited FLT3 kinase activity at low nanomolar concentrations. The lead compound, HSN431, also inhibited Src kinase activity. The compounds potently inhibited the viability of MV4-11 and MOLM-14 AML cells with IC50 values <1 nM. Furthermore, the viability of drug-resistant AML cells harboring the D835Y and F691 L mutations were potently inhibited. In vivo efficacy studies in mice demonstrated that the compounds could drastically reduce AML proliferation in mice. INTERPRETATION: Compounds that inhibit FLT3 and downstream targets like Src (for example HSN431) are good leads for development as anti-AML agents. FUND: Purdue University, Purdue Institute for Drug Discovery (PIDD), Purdue University Center for Cancer Research, Elks Foundation and NIH P30 CA023168.

Dual FLT3/TOPK inhibitor with activity against FLT3-ITD secondary mutations potently inhibits acute myeloid leukemia cell lines.

AIM: Approximately 30% of acute myeloid leukemia (AML) patients carry FLT3 tyrosine kinase domain (TKD) mutations or internal tandem duplication (FLT3-ITD). Currently there is a paucity of compounds that are active against drug-resistant FLT3-ITD, which contains secondary mutations in the TKD, mainly at residues D835/F691. RESULTS: HSD1169, a novel compound, is active against FLT3-ITD (D835 or F691). HSD1169 is also active against T-LAK cell-originated protein kinase (TOPK), a collaborating kinase that is highly expressed in AML cell lines. HSD1169 was active against MV4-11 and Molm-14 (FLT3-ITD cell lines) but not NOMO-1 or HL60 (FLT3-WT cell lines). HSD1169 was also active against sorafenib-resistant Molm13-res cell line (containing FLT3-ITD/D835Y). CONCLUSION: HSD1169 or an analog could become a therapeutic agent for AML containing drug-resistant FLT3-ITD.

Asparaginase Erwinia chrysanthemi effectively depletes plasma glutamine in adult patients with relapsed/refractory acute myeloid leukemia.

Depletion of glutamine (Gln) has emerged as a potential therapeutic approach in the treatment of acute myeloid leukemia (AML), as neoplastic cells require Gln for synthesis of cellular components essential for survival. Asparaginases deplete Gln, and asparaginase derived from Erwinia chrysanthemi (Erwinaze) appears to have the greatest glutaminase activity of the available asparaginases. In this Phase I study, we sought to determine the dose of Erwinaze that safely and effectively depletes plasma Gln levels to ≤ 120 µmol/L in patients with relapsed or refractory (R/R) AML. Five patients were enrolled before the study was halted due to issues with Erwinaze manufacturing supply. All patients received Erwinaze at a dose of 25,000 IU/m2 intravenously three times weekly for 2 weeks. Median trough plasma Gln level at 48 h after initial Erwinaze administration was 27.6 µmol/L, and 80% (lower limit of 1-sided 95% CI 34%) of patients achieved at least one undetectable plasma Gln value (< 12.5 µmol/L), with the fold reduction (FR) in Gln level at 3 days, relative to baseline, being 0.16 (p < 0.001 for rejecting FR = 1). No dose-limiting toxicities were identified. Two patients responded, one achieved partial remission and one achieved hematologic improvement after six doses of Erwinaze monotherapy. These data suggest asparaginase-induced Gln depletion may have an important role in the management of patients with AML, and support more pharmacologic and clinical studies on the mechanistically designed asparaginase combinations in AML.

Hydroxylated Dimeric Naphthoquinones Increase the Generation of Reactive Oxygen Species, Induce Apoptosis of Acute Myeloid Leukemia Cells and Are Not Substrates of the Multidrug Resistance Proteins ABCB1 and ABCG2.

Selective targeting of the oxidative state, which is a tightly balanced fundamental cellular property, is an attractive strategy for developing novel anti-leukemic chemotherapeutics with potential applications in the treatment of acute myeloid leukemia (AML), a molecularly heterogeneous disease. Dimeric naphthoquinones (BiQs) with the ability to undergo redox cycling and to generate reactive oxygen species (ROS) in cancer cells are a novel class of compounds with unique characteristics that make them excellent candidates to be tested against AML cells. We evaluated the effect of two BiQ analogues and one monomeric naphthoquinone in AML cell lines and primary cells from patients. All compounds possess one halogen and one hydroxyl group on the quinone cores. Dimeric, but not monomeric, naphthoquinones demonstrated significant anti-AML activity in the cell lines and primary cells from patients with favorable therapeutic index compared to normal hematopoietic cells. BiQ-1 effectively inhibited clonogenicity and induced apoptosis as measured by Western blotting and Annexin V staining and mitochondrial membrane depolarization by flow cytometry. BiQ-1 significantly enhances intracellular ROS levels in AML cells and upregulates expression of key anti-oxidant protein, Nrf2. Notably, systemic exposure to BiQ-1 was well tolerated in mice. In conclusion, we propose that BiQ-induced therapeutic augmentation of ROS in AML cells with dysregulation of antioxidants kill leukemic cells while normal cells remain relatively intact. Further studies are warranted to better understand this class of potential chemotherapeutics.