Novel Near-Infrared Fluorescent Probe for Hepatocyte Growth Factor in Vivo Imaging in Surgical Navigation of Colorectal Cancer.

Despite recent advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable primarily due to high recurrence and liver metastasis rates. Fluorescence molecular imaging technologies, combined with specific probes, have gained prominence in facilitating real-time tumor resection guided by fluorescence. Hepatocyte growth factor (HGF) is overexpressed in CRC, but the advancement of HGF fluorescent probes has been impeded by the absence of effective HGF-targeting small-molecular ligands. Herein, we present the targeted capabilities of the novel V-1-GGGK-MPA probe labeled with a near-infrared fluorescent dye, which targets HGF in CRC. The V-1-GGGK peptide exhibits high specificity and selectivity for HGF-positive in vitro tumor cells and in vivo tumors. Biodistribution analysis of V-1-GGGK-MPA revealed tumor-specific accumulation with low background uptake, yielding signal-to-noise ratio (SNR) values of tumor-to-colorectal >6 in multiple subcutaneous CRC models 12 h postinjection. Quantitative analysis confirmed the probe's high uptake in SW480 and HT29 orthotopic and liver metastatic models, with SNR values of tumor-to-colorectal and -liver being 5.6 ± 0.4, 4.6 ± 0.5, and 2.1 ± 0.3, 2.0 ± 0.5, respectively, enabling precise tumor visualization for surgical navigation. Pathological analysis demonstrated the excellent tumor boundaries discrimination capacity of the V-1-GGGK-MPA probe at the molecular level. With its rapid tumor targeting, sustained tumor retention, and precise tumor boundary delineation, V-1-GGGK-MPA merges as a promising HGF imaging agent, enriching the toolbox of intraoperative navigational fluorescent probes for CRC.

Design, synthesis, and evaluation of antitumor activity of Mobocertinib derivatives, a third-generation EGFR inhibitor.

Mobocertinib, as a structural analog of the third generation TKI Osimertinib, can selectively act on the EGFRex20 mutation. We have structurally modified Mobocertinib to obtain new EGFR inhibitors. In this paper, we chose Mobocertinib as a lead compound for structural modification to investigate the effect of Mobocertinib derivatives on EGFRT790M mutation. We designed and synthesized 63 Mobocertinib derivatives by structural modification using the structural similarity strategy and the bioelectronic isoarrangement principle. Then, we evaluated the in vitro antitumor activity of the 63 Mobocertinib derivatives and found that the IC50 of compound H-13 against EGFRL858R/T790M mutated H1975 cells was 3.91 µM, and in further kinase activity evaluation, the IC50 of H-13 against EGFRL858R/T790M kinase was 395.2 nM. In addition, the preferred compound H-13 was able to promote apoptosis of H1975 tumor cells and block the proliferation of H1975 cells in the G0/G1 phase; meanwhile, it was able to significantly inhibit the migratory ability of H1975 tumor cells and inhibit the growth of H1975 cells in a time-concentration-dependent manner. In the in vivo anti-tumor activity study, the preferred compound H-13 had no obvious toxicity to normal mice, and the tumor inhibition effect on H1975 cell-loaded nude mice was close to that of Mobocertinib. Finally, molecular dynamics simulations showed that the binding energy between compound H-13 and 3IKA protein was calculated to be -162.417 ± 14.559 kJ/mol. In summary, the preferred compound H-13 can be a potential third-generation EGFR inhibitor.

Preclinical evaluation of AGTR1-Targeting molecular probe for colorectal cancer imaging in orthotopic and liver metastasis mouse models.

Despite advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable for patients with distant liver metastasis. Fluorescence molecular imaging with specific probes is increasingly used to guide CRC surgical resection in real-time and treatment planning. Here, we demonstrate the targeted imaging capacity of an MPA-PEG4-N3-Ang II probe labeled with near-infrared (NIR) fluorescent dye targeting the angiotensin II (Ang II) type 1 receptor (AGTR1) that is significantly upregulated in CRC. MPA-PEG4-N3-Ang II was highly selective and specific to in vitro tumor cells and in vivo tumors in a mouse CRC xenograft model. The favorable ex vivo imaging and in vivo biodistribution of MPA-PEG4-N3-Ang II afforded tumor-specific accumulation with low background and >10 contrast tumor-to-colorectal values in multiple subcutaneous CRC models at 8 h following injection. Biodistribution analysis confirmed the probe's high uptake in HT29 and HCT116 orthotopic and liver metastatic models of CRC with signal-to-noise ratio (SNR) values of tumor-to-colorectal and -liver fluorescence of 5.8 ± 0.6, 5.3 ± 0.7, and 2.7 ± 0.5, 2.6 ± 0.5, respectively, enabling high-contrast intraoperative tumor visualization for surgical navigation. Given its rapid tumor targeting, precise tumor boundary delineation, durable tumor retention and docking study, MPA-PEG4-N3-Ang II is a promising high-contrast imaging agent for the clinical detection of CRC.

Rational design and synthesis of 2,4-dichloro-6-methyl pyrimidine derivatives as potential selective EGFRT790M/L858R inhibitors for the treatment of non-small cell lung cancer.

Many patients with non-small cell lung cancer (NSCLC) initially benefit from epidermal growth factor receptor (EGFR) targeted therapy. Unfortunately, varying degrees of resistance or side effects eventually develop. Overcoming and preventing the resistance and side effects of EGFR inhibitors has become a hot topic of research today. Based on the previous studies on AZD-9291, we designed and synthesized two series of 2,4-dichloro-6-methylpyrimidine derivatives, 19 compounds in total, as potential inhibitors of the EGFR kinase. The most promising compound, L-18, showed better inhibitory activity (81.9%) and selectivity against EGFRT790M/L858R kinase. In addition, L-18 showed strong antiproliferative activity against H1975 cells with an IC50 value of 0.65 ± 0.06 µM and no toxicity to normal cells (LO-2). L-18 was able to dose-dependently induce the apoptosis of H1975 cells and produced a cell-cycle-blocking effect, and it can also dose-dependently inhibit the migration and invasion of H1975 cells. L-18 also showed in vivo anticancer efficacy in H1975 cells xenograft mice. We also performed a series of in vivo and in vitro toxicological evaluations of compound L-18, which did not cause obvious injury in mice during administration. These results suggest that L-18 may be a promising drug candidate that warrants further investigation.

T6496 targeting EGFR mediated by T790M or C797S mutant: machine learning, virtual screening and bioactivity evaluation study.

Acquired resistance to EGFR is a major impediment in lung cancer treatment, highlighting the urgent need to discover novel compounds to overcome EGFR drug resistance. In this study, we utilized in silico methods and bioactivity evaluation for drug discovery to identify novel active anticancer agents targeting EGFRT790M/L858R and EGFRT790M/C797S/L858R. Firstly, we employed ROC-guided machine learning to retrieve nearly 7,765 compounds from a collection of three libraries (comprising over 220,000 compounds). Next, virtual screening, cluster analysis, and binding model analysis were employed to identify six potential compounds. Additionally, the kinase assay revealed that these six compounds demonstrated higher sensitivity to EGFR than c-Met. Among these compounds, T6496 inhibited both EGFRT790M/L858R and EGFRT790M/C797S/L858R kinases, with an IC50 of 3.30 and 8.72 µM. Furthermore, we evaluated the antitumor effects of the six selected compounds, and compound T6496 exhibited the strongest anticancer activity against H1975 cell lines, with an IC50 value of 2.7 µM. These results suggest that T6496 may mitigate EGFR resistance caused by T790M or C797S mutations. Moreover, the AO staining assay, JC-1 staining, ROS experiment and hemolytic toxicity evaluation revealed that T6496 could induce apoptosis in H1975 cell lines in a time-dependent and concentration-dependent manner, and is a potential compound for further structural optimization.Communicated by Ramaswamy H. Sarma.

ROC guided machine learning, virtual screening and bioevaluation was applied to discover six hit compounds for overcoming EGFR resistance mediated by T790M or C797S.The promising compound T6496 could both inhibit EGFR^T790M/L858R and EGFR^{T790M/C797S/L858R}, with an IC₅₀ of 3.30 and 8.72 µM.In addition, T6496 and AO-365/43489452 show excellent anticancer activity even better than AZD9291.AO staining assay, JC-1 staining, and ROS experiment revealed that compounds T6496 could induce apoptosis in H1975 cell lines in a time-dependent and concentration-dependent manner.

In silico screening combined with bioactivity evaluation to identify AMI-1 as a novel anticancer compound by targeting AXL.

Recently, some studies have proven that AXL plays a crucial role in the drug resistance of tumors. At present, no AXL inhibitors on the market and it is essential to discover novel compounds targeting AXL to overcome resistance. In this work, based on the anchor structure, 21,313 compounds were obtained by substructure search from more than 400,000 compounds. Then, the Qvina and Ledock were selected for virtual screening to obtain 17 compounds. Next, four compounds (ARRY614, AMI-1, NG25, and Butein) were selected for bioactivity evaluation after hydrogen bond and cluster analysis. Further activity evaluation suggested that the compound AMI-1 is a novel AXL inhibitor with an IC50 value of 1.13 uM. In addition, molecular dynamics simulation demonstrated that compound AMI-1 contained lower binding energy and more key residues than the other three compounds, showing the best inhibitory activity against AXL. Finally, further MM/PBSA prediction showed that AMI-1 is more sensitive to mutant protein 3IKA than wildtype protein 1M17, which means that the AMI-1 may be helpful to overcome the resistance of EGFRT790M mutations. In conclusion, this work successfully discovered a novel compound with moderate inhibitory activity against AXL by a drug discovery workflow, which also could be applied to discover active compounds for other targets quickly.Communicated by Ramaswamy H. Sarma.

Novel GRPR-Targeting Peptide for Pancreatic Cancer Molecular Imaging in Orthotopic and Liver Metastasis Mouse Models.

Despite advancements in pancreatic cancer treatment, it remains one of the most lethal malignancies with extremely poor diagnosis and prognosis. Herein, we demonstrated the efficiency of a novel peptide GB-6 labeled with a near-infrared (NIR) fluorescent dye 3H-indolium, 2-[2-[2-[(2-carboxyethyl)thio]-3-[2-[1,3-dihydro-3,3-dimethyl-5-sulfo-1-(3-sulfopropyl)-2H-indol-2-ylidene]ethylidene]-1-cyclohexen-1-yl]ethenyl]-3,3-dimethyl-5-sulfo-1-(3-sulfopropyl)-, inner salt (MPA) and radionuclide technetium-99m (99mTc) as targeting probes using the gastrin-releasing peptide receptor (GRPR) that is overexpressed in pancreatic cancer as the target. A short linear peptide with excellent in vivo stability was identified, and its radiotracer [99mTc]Tc-HYNIC-PEG4-GB-6 and the NIR probe MPA-PEG4-GB-6 exhibited selective and specific uptake by tumors in an SW1990 pancreatic cancer xenograft mouse model. The favorable biodistribution of the tracer [99mTc]Tc-HYNIC-PEG4-GB-6 in vivo afforded tumor-specific accumulation with high tumor-to-muscle and -bone contrasts and renal body clearance at 1 h after injection. The biodistribution analysis revealed that the tumor-to-pancreas and -intestine fluorescence signal ratios were 5.2 ± 0.3 and 6.3 ± 1.5, respectively, in the SW1990 subcutaneous xenograft model. Furthermore, the high signal accumulation in the orthotopic pancreatic and liver metastasis tumor models with tumor-to-pancreas and -liver fluorescence signal ratios of 7.66 ± 0.48 and 3.94 ± 0.47, respectively, enabled clear tumor visualization for intraoperative navigation. The rapid tumor targeting, precise tumor boundary delineation, chemical versatility, and high potency of the novel GB-6 peptide established it as a high-contrast imaging probe for the clinical detection of GRPR, with compelling additional potential in molecular-targeted therapy.

Preclinical Evaluation of CD36-Targeting Antiangiogenic Peptide ABT-510 for Near-Infrared Fluorescence Molecular Imaging of Colorectal Cancer.

Surgical resection constitutes the first choice of treatment for colorectal cancer (CRC). Despite advancements in intraoperative navigation, there remains a considerable lack of effective targeting probes for the imaging-guided surgical navigation of CRC owing to their high heterogeneity. Hence, developing a suitable fluorescent probe to detect the specific types of CRC populations is crucial. Herein, we labeled ABT-510, a small, CD36-targeting thrombospondin-1-mimetic peptide overexpressed in various cancer types, with fluorescein isothiocyanate or near-infrared dye MPA. We found that fluorescence-conjugated ABT-510 exhibited excellent selectivity and specificity toward cells or tissues with high CD36 expression. The tumor-to-colorectal signal ratios were 11.28 ± 0.61 (95% confidence interval) and 10.74 ± 0.07 (95% confidence interval) in subcutaneous HCT-116 and HT-29 tumor-bearing nude mice, respectively. Moreover, high signal contrast was observed in the orthotopic and liver metastatic CRC xenograft mouse models. Furthermore, MPA-PEG4-r-ABT-510 exhibited an antiangiogenic effect via tube information assay with human umbilical vein endothelial cells. Overall, MPA-PEG4-r-ABT-510 presents rapid and precise tumor delineation characteristics, thereby making it a desirable tool for CRC imaging and surgical navigation.

In vivo near-infrared fluorescence and SPECT-CT imaging of colorectal Cancer using the bradykinin B2R-specific ligand icatibant.

Cancer molecular imaging using specific probes designed to identify target proteins in cancer is a powerful tool to guide therapeutic selection, patient management, and follow-up. We demonstrated that icatibant may be used as a targeting probe for the significantly upregulated bradykinin B2R in colorectal cancer (CRC). Icatibant-based probes with high affinity towards bradykinin B2R were identified. The near-infrared (NIR) fluorescent dye conjugate MPA-PEG3-k-Icatibant and radioconjugate [99mTc]Tc-HYNIC-PEG4-Icatibant exhibited favourable selective and specific uptake in tumours when the subcutaneous and orthotopic colorectal tumour-bearing mouse models were imaged using NIR fluorescence imaging and Single-Photon Emission Computed Tomography-Computed Tomography (SPECT-CT), respectively. The tracer of [99mTc]Tc-HYNIC-PEG4-Icatibant accumulated in tumours according to biodistribution studies and peaked at 4 h with an uptake value of 3.41 ± 0.27%ID/g in HT29 tumour-bearing nude mice following intravenous injection (i.v.). The tumour-to-colorectal signal ratios were 5.03 ± 0.37, 15.45 ± 0.32, 13.58 ± 1.19 and 11.33 ± 1.73 1, 2, 4 and 6 h after tail-veil injection, respectively. Overall, in the wake of rapid and precise tumour delineation and penetration characteristics, icatibant-based probes represent promising high-contrast molecular imaging probes for the detection of bradykinin B2R.

In vivo assessing colitis severity by topical administration of fluorescent probe against neutrophils.

Inflammatory bowel disease has become a global burden given its high incidence and refractory to medical treatment. Improved diagnostic strategies to monitor disease activity more accurately are necessary to conduct and evaluate medical treatment. High level of neutrophil infiltration in colon is associated with poor prognosis and enhanced risk of developing colitis-associated cancer. Herein, to accurately monitor neutrophil levels in colitis condition, we designed and constructed a specific probe (CPM), consisting of a neutrophil formyl peptide receptor targeting group (cFLFLFK), a short PEG linker and a near-infrared fluorescent dye. CPM selectively identified neutrophils in vitro and preferentially recognized neutrophils in vivo with enhanced targeting ability and biodistribution property. After verified the ability to target activated neutrophils, CPM was used to detect neutrophils in experimental colitis by systemic and topical administration. Compared to systemic administration, topical administration of CPM allows lower dosage, higher target-to-background ratio and longer duration of effective monitoring. More importantly, we used CPM to assess neutrophil levels in the course of colitis development. The fluorescence intensity of CPM increased along with colitis progression. Additionally, CPM was used to detected neutrophil levels in colitis-associated cancer and enhanced neutrophil infiltration in the tumor sites was detected. In conclusion, the probe CPM is a promising tool for in vivo improved diagnosis of colitis severity by monitoring the extent of neutrophil infiltration.

Detection of colorectal cancer using a small molecular fluorescent probe targeted against c-Met.

Colorectal cancer (CRC), a highly heterogeneous genetic disease, is currently the second leading cause of cancer-related deaths worldwide. This malignant cancer is typically preceded by the development of precancerous lesions, which are challenging to distinguish their subtle morphologic changes. Molecular-based fluorescence imaging can effectively identify lesion targets to enhance image contrast and improve the detection of early neoplasia comparing to conventional wide-light screening endoscopy. C-Met has been identified as overexpressed in CRC advanced stage and has been suggested as a validated potential theranostic target. Herein, we developed a new small molecular fluorescence probe, namely Crizotinib-PEG4-MPA, specifically binds to c-Met in CRC cells and colitis-associated cancer adenoma. In vitro binding studies confirmed the specificity and selectively of Crizotinib-PEG4-MPA against c-Met, the corresponding apparent equilibrium dissociation constants (Kd) was 3.86 µM for Crizotinib-PEG4-MPA. Additionally, the probe was carried out to c-Met positive tumor-bearing mice in vivo to explore the diagnostic potential clinical value, the method used a randomized block design to cluster mice into groups and found the tumor/normal signal ratio value up to 4.23 (95% confidence interval (CI) 4.07-4.39) at 6 h. More importantly, Crizotinib-PEG4-MPA was used to detect the occurrence of the colon adenoma and the in vivo imaging results showed the mean fluorescence intensity of the CAC colon is significantly higher than that in the normal group (P < 0.001). Furthermore, the immunofluorescence signals of biopsies samples demonstrated the probe indeed targets the c-Met and possesses the property to distinguish colon adenoma from normal colon tissue. Altogether, this novel fluorescence probe, with excellent C-met-targeting ability, has a substantial potential to serve as a widely available in vivo tracer for the early diagnosis and monitoring of colorectal cancer.

AT1R-Specific Ligand Angiotensin II as a Novel SPECT Agent for Hepatocellular Carcinoma Diagnosis.

Hepatocellular carcinoma (HCC) is characterized by a high mortality and early diagnosis and treatment are critically needed. Ang II type 1 receptor (AT1R) has recently emerged as a potential molecular target for cancer diagnosis and intervention. Here, we labeled angiotensin II (Ang II), an AT1R ligand that is overexpressed in various solid cancers, with the near-infrared fluorescent dye, MPA, and radionuclide technetium-99m, and evaluated its capacity for HCC detection. These analyses were done in vitro using HepG2 (AT1R-positive) and BxPC3 (AT1R-negative) cell lines, and in vivo using a subcutaneous and orthotopic xenograft mouse model by fluorescence and SPECT imaging. Both Ang II-PEG4-MPA- and [99mTc]Tc-HYNIC-PEG4-Ang II-bound AT1R exhibited a high affinity in vitro and [99mTc]Tc-HYNIC-PEG4-Ang II displayed an acceptable level of in vitro stability in rat plasma and whole blood. In vivo imaging revealed excellent specific tumor-targeting in HepG2 mouse xenografts models. In vitro and in vivo competition experiments revealed specific Ang II-PEG4-MPA and [99mTc]Tc-HYNIC-PEG4-Ang II uptake by HepG2 cells and tumors. Altogether, AT1R-positive tumors were successfully detected via fluorescence and SPECT imaging using Ang II-PEG4-MPA and [99mTc]Tc-HYNIC-PEG4-Ang II, respectively. Given their superior targeting capacity, Ang II-PEG4-MPA and [99mTc]Tc-HYNIC-PEG4-Ang II are promising tools for HCC detection and warrant clinical translation.

GRPR-targeted SPECT imaging using a novel bombesin-based peptide for colorectal cancer detection.

Colorectal cancer (CRC) is the third most common cancer worldwide, and the prognosis of CRC is better with an earlier diagnosis. The presence of the gastrin-releasing peptide receptor (GRPR) has been documented in very high numbers on colorectal cancer cells, which makes it an ideal biomarker for the diagnosis of CRC. Bombesin (BBN) peptide analogs have been extensively investigated for the imaging of human cancers with GRPR overexpression. Recently, we have reported a novel GRPR-targeted peptide named the GB-6 peptide. The GB-6 peptide based on BBN7-14 was designed to improve in vivo metabolic stability and decrease intestinal uptake. Meanwhile, GB-6 greatly retained the original GRPR-binding affinity of BBN7-14. In this study, the GB-6 peptide was labeled with radionuclide 99mTc or fluorescent dye for colorectal cancer imaging. In vitro receptor binding was studied in Caco-2 cells, and the GRPR targeting capacity and kinetics in vivo were evaluated using Caco-2 tumor xenografted mice models. In addition, cells and mice were also subjected to the corresponding BBN7-14 conjugations for comparison. The GB-6 peptide exhibited specific GRPR binding in vitro with a high affinity similar to that of BBN7-14. Furthermore, we observed that GB-6 showed higher tumor uptake and displayed lower intestinal activity than corresponding unmodified probe BBN7-14 in Caco-2 tumor-bearing mice. Overall, our studies demonstrated that GB-6 has the potential for early detection of CRC patients, and it may also serve as a valuable tool for non-invasive monitoring of colorectal tumor growth.

A frog-derived bionic peptide with discriminative inhibition of tumors based on integrin αvß3 identification.

Aureins, natural active peptides extracted from skin secretions of Australian bell frogs, have become a research focus due to the antitumor effects caused by lysing cell membranes. However, clinical translation of Aureins is still limited by non-selective toxicity between normal and cancer cells. Herein, by structure-activity relationship analysis and rational linker design, a dual-function fusion peptide RA3 is designed by tactically fusing Aurein peptide A1 with strong anticancer activity, with a tri-peptide with integrin αvß3-binding ability which was screened in our previous work. Rational design and selection of fusion linkers ensures α-helical conformation and active functions of this novel fusion peptide, inducing effective membrane rupture and selective apoptosis of cancer cells. The integrin binding and tumor recognition ability of the fusion peptide is further validated by fluorescence imaging in cell and mouse models, in comparison with the non-selective A1 peptide. Meanwhile, increased stability and superior therapeutic efficacy are achieved in vivo for the RA3 fusion peptide. Our study highlights that aided by computational simulation technologies, the biomimetic fusion RA3 peptide has been successfully designed, surmounting the poor tumor-selectivity of the natural defensive peptide, serving as a promising therapeutic agent for cancer treatment.

A novel peptide targeting gastrin releasing peptide receptor for pancreatic neoplasm detection.

Pancreatic cancer has a high mortality rate and efforts towards diagnosis and therapy at an early stage are particularly appealing. Recently, a small peptide, BBN7-14, has attracted much attention for its specific binding ability to gastrin releasing peptide receptor (GRPR), which is highly overexpressed in various types of cancer, including pancreatic cancer. However, its poor stability in vivo restricts its direct clinical application. Herein, by rational design and transformation of BBN7-14, a novel six-amino acid peptide, GB-6, which maintains a specific GRPR-binding feature and exhibits enhanced stability in vitro and in vivo, was designed. Competitive binding with BBN7-14 and cellular uptake related to GRPR expression levels verified the specific affinity of GB-6 to GRPR. Additionally, this novel peptide was conjugated with near-infrared dye and the radionuclide 99mTc for pancreatic cancer diagnosis in cells and in vivo. Surprisingly, despite having the same cellular affinity as BBN7-14, GB-6 showed much higher pancreatic cancer-targeting ability than BBN7-14 by both fluorescence imaging and radionuclide imaging. It was proven that this strange phenomenon was attributed to the distinct in vivo stability of GB-6 and its more favorable pharmacokinetic properties and metabolic stability relative to BBN7-14. Altogether, this novel peptide GB-6, with GRPR-targeting ability and enhanced stability, is a more promising candidate for the clinical diagnosis of pancreatic cancer.

Homotypic targeting upconversion nano-reactor for cascade cancer starvation and deep-tissue phototherapy.

Cancer starvation therapy based on catalytic chemistry of glucose oxidase (GOx) offers great potential for multimodal treatment, benefiting from both nutrition shutting-off and the oxidization product hydrogen peroxide (H2O2). Herein, further optimization of such combined therapy was achieved by a cascade Nano-reactor, which was constructed by incorporating GOx into a bio-mimic upconversion nanosystem. The cascade began when GOx was delivered into tumor sites through homotypic targeting, facilitating selective starving of cancer cells and H2O2 generation. Then, upon 980 nm laser excitation, the 470 nm light emitted by upconversion nanoparticles (NaYF4: Yb, Tm) photolyzed H2O2 into hydroxyl radical for phototherapy, superior to direct photolysis by blue light with limited tissue penetration depth. Meanwhile, the 800 nm emission of UCNPs was used to track the in vivo fate and tumor targeting ability of the Nano-reactor. Radionuclide imaging further confirmed the targeting of the Nano-reactor to subcutaneous 4T1 tumor and lung metastasis. Significantly enhanced therapeutic efficacy of this cascade starvation-phototherapy was validated in vitro and in vivo, suggesting the Nano-reactor as a smart, simple and strong system for cancer multimodal therapy.

Discovery of novel quinazoline derivatives bearing semicarbazone moiety as potent EGFR kinase inhibitors.

Aimed at discovering effective EGFR inhibitors, six series of quinazoline derivatives bearing a semicarbazone moiety were designed, synthesized and evaluated in different cancer cell lines (A549, HepG2, MCF-7 and PC-3). Most of the selected compounds showed remarkable cytotoxicity with IC50 values reaching the nanomole range. Further, the inhibition efficacy of 11 compounds against EGFR kinases was tested, which demonstrated excellent IC50 values in nanomolar level. Importantly, 2 compounds exhibited IC50 values of 0.05 nM and 0.1 nM against wild type EGFR respectively, suggesting more potent activities than that of the positive control, Afatinib (4.0 nM). Excitingly, 2 compounds showed excellent enzyme inhibitory activity with 8.6 nM and 5.6 nM for double T790 M/L858R mutant EGFRs, which is almost the same as Afatinib (3.8 nM). Structure-activity relationships (SARs) analysis indicated that the type of small molecule amine in pyrrole moiety or the chain length of pyrrolamine moiety had no obvious impact on the inhibition efficacy of our synthesized compounds against cancer cells. In addition, results of cell cycle analysis indicated that the G2/M phase of A549 cells was efficiently arrested by the selected compounds. These preliminary results demonstrate that 2 compounds may be promising lead compound-targeting EGFR.

Design, synthesis, and docking studies of quinazoline analogues bearing aryl semicarbazone scaffolds as potent EGFR inhibitors.

Two series of quinazoline derivatives bearing aryl semicarbazone scaffolds (9a-o and 10a-o) were designed, synthesized and evaluated for the IC50 values against four cancer cell lines (A549, HepG2, MCF-7 and PC-3). The selected compound 9o was further evaluated for the inhibitory activity against EGFR kinases. Four of the compounds showed excellent cytotoxicity activity and selectivity with the IC50 values in single-digit µM to nanomole range. Two of them are equal to more active than positive control afatinib against one or more cell lines. The most promising compound 9o showed the best activity against A549, HepG2, MCF-7 and PC-3 cancer cell lines and EGFR kinase, with the IC50 values of 1.32±0.38µM, 0.07±0.01µM, 0.91±0.29µM and 4.89±0.69µM, which were equal to more active than afatinib (1.40±0.83µM, 1.33±1.28µM, 2.63±1.06µM and 3.96±0.59µM), respectively. Activity of the most promising compound 9o (IC50 56nM) against EGFR kinase was slightly lower to the positive compound afatinib (IC50 1.6nM) but more active than reference staurosporine (IC50 238nM). The result of flow cytometry, with the dose of compound 9o increasing, which indicated the compound 9o could induce remarkable apoptosis of A549 and cells in a dose dependent manner. Structure-activity relationships (SARs) and docking studies indicated that replacement of the cinnamamide group by aryl semicarbazone scaffolds slightly decreased the anti-tumor activity. The results suggested that hydroxy substitution at C-4 had a significant impact on the activity and replacement of the tetrahydrofuran group by methyl moiety was not beneficial for the activity.

Design, synthesis, and docking studies of afatinib analogs bearing cinnamamide moiety as potent EGFR inhibitors.

Two series of afatinib derivatives bearing cinnamamide moiety (10a-n and 11a-h) were designed, synthesized and evaluated for the IC50 values against four cancer cell lines (A549, PC-3, MCF-7 and Hela). Two selected compounds (10e, 10k) were further evaluated for the inhibitory activity against EGFR and VEGFR2/KDR kinases. Seven of the compounds showed excellent cytotoxicity activity and selectivity with the IC50 values in single-digit µM to nanomole range. Three of them are equal to more active than positive control afatinib against one or more cell lines. The most promising compound 10k showed the best activity against A549, PC-3, MCF-7 and Hela cancer cell lines and EGFR kinase, with the IC50 values of 0.07 ± 0.02 µM, 7.67 ± 0.97 µM, 4.65 ± 0.90 µM and 4.83 ± 1.28 µM, which were equal to more active than afatinib (0.05 ± 0.01 µM, 4.1 ± 2.47 µM, 5.83 ± 1.89 µM and 6.81 ± 1.77 µM), respectively. Activity of compounds 10e (IC50 9.1 nM) and 10k (IC50 3.6 nM) against EGFR kinase were equal to the reference compound afatinib (IC50 1.6 nM). Structure-activity relationships (SARs) and docking studies indicated that replacement of the aqueous solubility 4-(dimethylamino)but-2-enamide group by cinnamamide moiety didn't decrease the antitumor activity. The results suggested that methoxy substitution had a significant impact on the activity and methoxy substituted on C-4 or C-2,3,4 position was benefit for the activity.