The HDAC2-MTA3 interaction induces nonsmall cell lung cancer cell migration and invasion by targeting c-Myc and cyclin D1.

Genome-wide association studies have identified numerous single-nucleotide polymorphisms (SNPs) associated with lung cancer; however, the functions of histone deacetylase 2 (HDAC2) rs13213007 and HDAC2 in nonsmall cell lung cancer (NSCLC) remain unclear. Here we identified HDAC2 rs13213007 as a risk SNP and showed that HDAC2 was upregulated in both peripheral blood mononuclear cells (PBMCs) and NSCLC tissues with the rs13213007 A/A genotype compared with those with the rs13213007 G/G or G/A genotype. Patient clinical data indicated strong associations between rs13213007 genotype and N classification. Immunohistochemical staining confirmed that higher expression of HDAC2 was associated with NSCLC progression. Furthermore, we generated 293T cells with the rs13213007 A/A genotype using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 gene editing. Chromatin immunoprecipitation sequencing followed by motif analysis showed that HDAC2 can bind to c-Myc in rs13213007 A/A 293T cells. Cell Counting Kit-8, colony formation, wound-healing, and Transwell assays revealed that HDAC2 upregulates c-Myc and cyclin D1 expression and promotes NSCLC cell proliferation, migration, and invasion. Co-immunoprecipitation, quantitative reverse transcription-polymerase chain reaction, and western blot analysis assays showed that MTA3 interacts with HDAC2, decreases HDAC2 expression, and rescues the migration and invasion abilities of NSCLC cells. Taken together, these findings identify HDAC2 as a potential therapeutic biomarker in NSCLC.

Impact of Somatic Mutations in Non-Small-Cell Lung Cancer: A Retrospective Study of a Chinese Cohort.

BACKGROUND: Somatic mutations are important biomarkers for selecting an optimal targeted therapy and predicting outcomes for non-small-cell lung cancer (NSCLC) patients that are often detected from tissue samples. However, tissue samples are not always readily available from these patients. The exploration of using circulating tumor DNA (ctDNA) to identify somatic mutations offers an alternative source that should be explored. METHODS: In this retrospective study, we included 280 patients diagnosed with adenocarcinoma between 2017 and 2018 in a hospital in eastern China. Tissue or ctDNA was collected, and a wide spectrum of somatic mutations was analyzed by targeted next-generation sequencing platforms. Associations among the mutation status, biomarkers, screening methods, disease stages, and interaction with treatment with overall survival (OS) were investigated. RESULTS: We found that the EGFR L858R mutation was the most frequently identified mutation in adenocarcinoma in this population by both methods, followed by KRAS (p=3.7e-09), PIK3CA (p=5e-04), and HER2 mutations (p=6.3e-03). We observed that EGFR mutations were significantly mutually exclusive with KRAS, HER2, and MET. FGFR1 mutations were significantly more abundantly detected in the ctDNA group. We found an interaction effect between EGFR mutation and target therapies. The ability of the targeted therapy to improve OS in patients with a single EGFR mutation (HR=0.069, p=0.07) approached significance, but this was not the case for the patients with more than one EGFR mutation or without an EGFR mutation (HR=0.813, p=0.725). Furthermore, the effect of chemotherapy was more predominant in the EGFR group in comparison to the control group. CONCLUSION: These findings provide useful information on the distribution of somatic mutations via different screening methods and how this related to the optimal treatment selection in Chinese patients with NSCLC.

Total synthesis of 7-ethyl-10-hydroxycamptothecin (SN38) and its application to the development of C18-functionalized camptothecin derivatives.

A new chemical synthesis of SN38, the active metabolite of the camptothecin prodrug irinotecan, has been achieved in 12 steps from simple, commercially available starting materials. A mild and efficient FeCl(3)-catalyzed Friedländer condensation was successfully applied to construct the AB ring system. Functionalization of the C ring was accomplished by a vinylogous Mukaiyama reaction of an in situ generated N-acyliminium intermediate with a silyl enol ether. An intramolecular oxa Diels-Alder reaction efficiently constructed the D and E rings in one step. Successive asymmetric dihydroxylation and I(2) -based hemiacetal oxidation furnished the stereochemistry of SN38 with high enantiopurity. Utilizing the ABC-ring intermediate and a functionalized silyl enol ether permitted the synthesis of a number of new C18-functionalized SN38 derivatives. Several of the novel SN38 derivatives that bore a C10 methoxy group were found to exhibit comparable or more potent inhibitory activity against the proliferation of cancer cells relative to SN38.

Efficient total synthesis of (S)-14-azacamptothecin.

An efficient total synthesis of (S)-14-azacamptothecin has been accomplished in 10 steps and 56% overall yield from 5H-pyrano[4,3-d]pyrimidine 8. A mild Hendrickson reagent-triggered intramolecular cascade cyclization, a highly enantioselective dihydroxylation, and an efficient palladium-catalyzed transformation of an O-allyl into N-allyl group are the key steps in the synthesis. This work provides a much higher overall yield than the previous achievement and shows sound flexibility for the further applications that will lead to new bioactive analogues.

Expeditious total syntheses of camptothecin and 10-hydroxycamptothecin.

New expeditious total syntheses of (S)-camptothecin (16% overall yield, 95% ee) and (S)-10-hydroxycamptothecin (14% overall yield, 99% ee) have been accomplished, respectively, starting from readily available and inexpensive materials. Development, optimization, and successful application of the cascade reaction consisting of a pyrrolidine-catalyzed Michael addition, an intramolecular aldol condensation, and an oxidative aromatization, the intramolecular oxa Diels-Alder cycloaddition, and the Sharpless asymmetric dihydroxylation make these two new syntheses more efficient and straightforward.

Biomimetic total syntheses of cassiarins A and B.

Total syntheses of cassiarins A and B have been efficiently accomplished using a common strategy with biomimetic considerations. Key reactions involved in this synthesis include a Negishi-type coupling, a Ag(I)-promoted formation of the tricyclic 8H-pyrano[2,3,4-de]chromen-8-one core, and a sequential amine-condensation and cyclization. Three new analogues of cassiarin A bearing different substituents at the C-11 position were synthesized in parallel from the same intermediate. In addition, two other transformations to the key tricyclic cores and cassiarins A and B were achieved from corresponding chemically equivalent precursors.