Abstract: Introduction:
Gene fusion variants in ALK-rearranged NSCLC may predict patient outcomes, but previous results have been inconclusive. Fusion isoforms coexisting in the same tumor may affect the efficacy of targeted therapy, but they have not been investigated.
Methods:
Patients with ALK-rearranged NSCLC who received crizotinib treatments were recruited. Precrizotinib tumor tissues were analyzed by the anchored multiplex polymerase chain reaction for targeted RNA sequencing. Kaplan-Meier and Cox regression were used to compare overall and progression-free survivals.
Results:
Of the 51 studied subjects, EML4-ALK variant types v1, v2, v3, and others were detected in 23 (45.1%), five (9.8%), 19 (37.3%), and four patients (7.8%), respectively. Multiple EML4-ALK RNA isoforms were detected in 24 tumors (47.1%), and single isoform in 27 (52.9%). Most of the v3 tumors (16 of 19) harbored both v3a and v3b RNA isoforms. Multiple isoforms were also detected in eight non-v3 tumors (33.3% of all 24 multiple isoforms; five v1, two v5′, and one v2). Compared with patients with single isoform, those with multiple isoforms had worse progression-free (hazard ratio and 95% confidence interval: 2.45 [1.06–5.69]) and overall (hazard ratio [95% confidence interval]: 3.74 [1.26–11.13]) survivals after adjusting for potential confounders including variant type. Using the patient-derived H2228 cells known to express v3a and v3b, our single-cell polymerase chain reaction detected either v3a or v3b in most single cells. Treatment of H2228 cells by three ALK inhibitors revealed increased ratios of v3a-to-v3b expression over time.
Conclusions:
Intratumoral EML4-ALK isoforms may predict the efficacy of targeted therapy in ALK-rearranged NSCLC. Temporal changes of intratumoral fusion isoforms may result from differential selection pressures that a drug might have on one isoform over another. Larger studies on fusion heterogeneity using RNA sequencing are warranted.
* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With N-ethyl-N,N-diisopropylamine; In acetonitrile; at 90℃;
Compounds 1-1 and 3- (bromomethyl) -3-methyloxetanone were added(2 eq) was dissolved in acetonitrile, DIPEA (3 eq) was added and heated to 90 C overnight. After completion of the reaction, the reaction solution was cooled, slowly poured into ice water, extracted three times with ethyl acetate. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate and mixed with the column. CH2C12: Mu0Eta = 30: 1 S2
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
