Improvements in the Synthesis of the Third-Generation EGFR Inhibitor Osimertinib

Osimertinib, a third generation potent and specific EGFR inhibitor is an important drug against many forms of cancer. It was synthesized by an improved and highly efficient protocol, revisiting the classical synthetic process and modifying parameters, such as solvents, temperature, reagents, and reaction time. A cost-effective, environmentally friendly methodology for the synthesis of osimertinib was established, which gave shorter reaction times, saved labor by eliminating purification steps through column chromatography, and enhanced yields. Four of the seven steps in total, were proceeded quantitatively or almost quantitatively (ca. 98 %). This synthetic protocol provides a very high overall yield, up to 68 %. In addition, the entire approach enables the preparation of osimertinib analogues and could be extended in the synthesis of other structurally similar bioactive compounds.     

Application of FTIR Spectroscopy for Identification of Blood and Leukemia Biomarkers: A Review over the Past 15 Years

Abstract

Fourier transform infrared (FTIR) spectroscopy is an effective and nondestructive method for monitoring cellular alterations. Combining the advantages of FTIR spectroscopy with the challenge of cellular characterization, the main objective of this review is to collect information related to the spectroscopic identification of blood cells, focusing on specific biochemical features of leukemia cells detected through FTIR spectral analysis. Some interesting results obtained by different authors regarding human promyelocytic leukemia, white blood cells, chronic lymphocytic leukemia, and human peripheral blood mononuclear cells are presented. In addition, the characterization of two types of cells, namely, leukemia T and a healthy human blood cells, is reported and the identification of biochemical markers provides important information that, associated with clinical examination, can assist in the diagnosis of diseases.     

Chemotherapy control by breath profile with application of SPME‐GC/MS method

Chemotherapy used as a treatment against lung cancer has influence on metabolic processes occurring in healthy cells. The changes of biochemical pathways proceeded inside cells might be observed in expired air. In the experiment, breath analysis was carried out before and after anticancer therapy. Expired air samples were collected from 22 patients with a biopsy confirmed lung cancer. Volatile organic compounds present in breath were analyzed by gas chromatography/mass spectrometry. For enrichment of analytes solid‐phase microextraction technique was applied. Eight fibers covered by different sorbents were tested. Carboxen‐polydimethylsiloxane fiber revealed the highest extraction efficiency in relation to analytes in breath. The data showed that cytostatic drugs increase the concentration of acetone and isoprene in the breath collected after chemotherapy. Volatile metabolites of administrated drugs were not identified in expired air.     

Camptothecin@HMSNs/thermosensitive hydrogel composite for applications in preventing local breast cancer recurrence

The CPT was loaded into the HMSNs with the high loading capacity. Then the CPT@HMSNs were loaded into the PLEL thermosensitive hydrogels for local therapy to prevent the recurrence of breast cancer after the tumor was resected.     

大黄素联合5AzA-cdR对胰腺癌抑癌基因p16、RASSF1A去甲基化作用研究

目的研究大黄素是否可增强5AzA-cdR对胰腺癌Panc1细胞抑癌基因p16、RASSF1A的去甲基化作用。方法采用细胞增殖实验检测不同浓度大黄素对Panc1细胞的生长抑制情况，焦磷酸盐测序PCR（BSP）分别检测大黄素、5AzA-cdR及大黄素联合5AzA-cdR对Panc1细胞抑癌基因p16、RASSF1A甲基化状态的影响，并用荧光定量PCR（FQ-PCR）和Westernblot分别检测p16、RASSF1A及甲基转移酶DNMT1、DNMT3a在mRNA和蛋白水平的表达情况。结果大黄素以时间和浓度梯度依赖性抑制Panc1细胞生长。BSP结果显示大黄素具有微弱的去甲基化作用，5AzA-cdR具有一定程度的去甲基化作用，当两者联用时，去甲基化作用更加显著；FQ-PCR和Westernblot结果显示大黄素与5AzA-cdR联用时，p16、RASSF1A的表达水平均较空白对照明显增高（均P＜0.05），DNMT1、DNMT3a的表达水平均较空白对照明显降低（均P＜0.05）。结论大黄素与5AzA-cdR联用可通过降低DNMT1和DNMT3a的表达水平来增强5AzA-cdR对胰腺癌抑癌基因p16、RASSF1A的去甲基化作用。     

In Situ Proteome Profiling and Bioimaging Applications of Small‐Molecule Affinity‐Based Probes Derived From DOT1L Inhibitors

DOT1L is the sole protein methyltransferase that methylates histone H3 on lysine 79 (H3K79), and is a promising drug target against cancers. Small‐molecule inhibitors of DOT1L such as FED1 are potential anti‐cancer agents and useful tools to investigate the biological roles of DOT1L in human diseases. FED1 showed excellent in vitro inhibitory activity against DOT1L, but its cellular effect was relatively poor. In this study, we designed and synthesized photo‐reactive and “clickable” affinity‐based probes (AfBPs), P1 and P2 , which were cell‐permeable and structural mimics of FED1 . The binding and inhibitory effects of these two probes against DOT1L protein were extensively investigated in vitro and in live mammalian cells (in situ). The cellular uptake and sub‐cellular localization properties of the probes were subsequently studied in live‐cell imaging experiments, and our results revealed that, whereas both P1 and P2 readily entered mammalian cells, most of them were not able to reach the cell nucleus where functional DOT1L resides. This offers a plausible explanation for the poor cellular activity of FED1 . Finally with P1 / P2 , large‐scale cell‐based proteome profiling, followed by quantitative LC‐MS/MS, was carried out to identify potential cellular off‐targets of FED1 . Amongst the more than 100 candidate off‐targets identified, NOP2 (a putative ribosomal RNA methyltransferase) was further confirmed to be likely a genuine off‐target of FED1 by preliminary validation experiments including pull‐down/Western blotting (PD/WB) and cellular thermal shift assay (CETSA).     

Structure‐cytotoxicity relationship for apoptotic inducers organotin(IV) derivatives of mandelic acid and L‐proline and their mixed ligand complexes having enhanced cytotoxicity

Structure‐cytotoxicity relationship of di?/tri‐organotin(IV) derivatives of mandelic acid ( 1 – 4 ), L‐proline ( 5 – 7, 15, 16 ), and mixed ligand complexes of latter with 1,10‐phenanthroline ( 8 – 14 ) investigated on the basis of MTT assay against human cancer cell lines, viz. MCF‐7 (mammary cancer), HepG2 (liver cancer) and PC‐3 (prostate cancer) in vitro indicated that all complexes except methyl‐ and octyl‐ analogues displayed potential cytotoxicity. The most active one is dibutyltin(IV) mandelate ( 2 ) exhibiting IC₅₀ 2.03 ± 0.40, 0.98 ± 0.23 and 3.86 ± 1.68 μM against MCF‐7, HepG2 and PC‐3, respectively, which is ≈ 15 and 2.5 times against MCF‐7, 20 and 5 times against HepG2 and 5 and ≈ 3 times against PC‐3 more cytotoxic than cis‐platin and 5‐fluorouracil, respectively. Diorganotin(IV) derivatives of mandelic acid are more cytotoxic than triorganotin analogues. Organotin(IV) derivatives of L‐proline (except Bu₃Sn(Pro) 16 ) are less cytotoxic than those of mandelic acid but their cytotoxicity is enhanced by complexion with 1,10‐phenanthroline. This may be due to the structural planarity and extended π system of 1,10‐phenanthroline which facilitates their transportation across the cell membrane and enhances the possibility of DNA intercalation over the planar L‐proline ring, and eventually, their DNA binding affinity so as to interfere with the cellular functions of DNA leading to apoptosis. Various biophysical experiments such as DNA fragmentation, acridine orange and comet assays, and flow cytometry assay using annexin V–fluorescein isothiocyanate (FITC) and propidium iodide (PI) have been carried out in order to ascertain their mode of action. The observed results indicated that the major cause of cancer cell death is apoptosis, but a minor role played by necrosis cannot be excluded. It is concluded on the basis of the observed results that the nature and number of organic groups bonded to tin as well as the nature of counter anions play an important role in determining the cytotoxicity of organotin(IV) compounds.