Expression of EGFR-mutant proteins and genomic evolution in EGFR-mutant transformed small cell lung cancer

Background

The transformation of epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD) into small cell lung cancer (SCLC) accounts for 3-14% of the resistance mechanism to EGFR tyrosine kinase inhibitors (TKIs). At present, there is no relevant research to explore the dynamic expression of EGFR-mutant proteins and genomic evolution in EGFR-mutant transformed SCLC/neuroendocrine carcinoma (NEC).

Methods

Genetic analysis and protein level analysis by next-generation sequencing (NGS), Whole-exome sequencing (WES) and immunohistochemistry were performed to explore expression of EGFR-mutant proteins and genomic evolution in EGFR-mutant transformed SCLC. The research used three patient-derived organoids (PDOs) to explore the efficacy of combo [chemotherapy (chemo) plus TKI or bevacizumab] treatment. According to the subsequent treatment regimens after SCLC/NEC transformation, 35 patients were divided into chemo (n=21) and combo (n=14) groups.

Results

EGFR L858R and EGFR E746-750 del protein expression by immunohistochemistry was 80.0% (4/5) and 100% (6/6), respectively (P=0.455) in initially-transformed tissues. Meanwhile, EGFR-mutant proteins were expressed in 85.7% (6/7) of dynamic rebiopsy tissues or effusion samples after the first transformation. Then, by the pathway enrichment analysis of tissue and plasma NGS, the EGFR-related pathways were still activated after SCLC/NEC transformation. Moreover, WES analysis revealed that transformed SCLC shared a common clonal origin from the baseline LUAD. The drug sensitivity of three PDOs demonstrated potent anti-cancer activity of EGFR-TKIs plus chemo, compared with chemo or TKI alone. There were significant differences in objective response rate (ORR) between the combo and chemo groups [42.9 % vs. 4.8%, P=0.010, 95% confidence interval (CI): 1.5-145.2]. Furthermore, the median post-transformation progression-free survival (pPFS) was significantly prolonged in the combo group, with 5.4 (95% CI: 3.4-7.4) versus 3.5 (95% CI: 2.7-4.3, P=0.012) months.

Conclusions

EGFR 19del or L858R-mutant proteins could be constantly expressed, and EGFR pathway still existed in EGFR-mutant transformed SCLC/NEC with a common clonal origin from the baseline LUAD. Taking together, these molecular characteristics potentially favored clinical efficacy in transformed SCLC/NEC treated with the combo regimen.

PD-1/PD-L1 combined with LAG3 is associated with clinical activity of immune checkpoint inhibitors in metastatic primary pulmonary lymphoepithelioma-like carcinoma

Primary pulmonary lymphoepithelioma-like carcinoma (PLELC) is an Epstein–Barr virus (EBV)-related, rare subtype of non-small-cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICI) show durable responses in advanced NSCLC. However, their effects and predictive biomarkers in PLELC remain poorly understood. We retrospectively analyzed the data of 48 metastatic PLELC patients treated with ICI. Pretreated paraffin-embedded specimens (n = 19) were stained for PD-1, PD-L1, LAG3, TIM3, CD3, CD4, CD8, CD68, FOXP3, and cytokeratin (CK) by multiple immunohistochemistry (mIHC). Next-generation sequencing was performed for 33 PLELC samples. Among patients treated with ICI monotherapy (n = 30), the objective response rate (ORR), disease control rate (DCR), median progression-free survival (mPFS), and overall survival (mOS) were 13.3%, 80.0%, 7.7 months, and 24.9 months, respectively. Patients with PD-L1 ≥1% showed a longer PFS (8.4 vs. 2.1 months, p = 0.015) relative to those with PD-L1 <1%. Among patients treated with ICI combination therapy (n = 18), ORR, DCR, mPFS, and mOS were 27.8%, 100.0%, 10.1 months, and 19.7 months, respectively. Patients with PD-L1 ≥1% showed a significantly superior OS than those with PD-L1 <1% (NA versus 11.7 months, p = 0.001). Among the 19 mIHC patients, those with high PD-1/PD-L1 and LAG3 expression showed a longer PFS (19.0 vs. 3.9 months, p = 0.003). ICI also showed promising efficacy for treating metastatic PLELC. PD-L1 may be both predictive of ICI treatment efficacy and prognostic for survival in PLELC. PD-1/PD-L1 combined with LAG3 may serve as a predictor of ICI treatment effectiveness in PLELC. Larger and prospective trials are warranted to validate both ICI activity and predictive biomarkers in PLELC.

This study was partly presented as a poster at the IASLC 20th World Conference on Lung Cancer 2019, 7–10 September 2019, Barcelona, Spain.

An integrated biomarker of PD-L1 expression and intraepithelial CD8+ T cell infiltration was associated with the prognosis of lung cancer patients after intracranial resection of brain metastases

Background

Brain metastases (BM) are common in lung cancer. However, data on the status of immune biomarkers in BM lesions remain limited.

Methods

We retrospectively analyzed PD‐L1 expression and infiltration levels of CD3⁺, CD4⁺, CD8⁺ T cells as biomarkers by immunohistochemistry in both BM lesions and primary lung cancer (PL) lesions of 29 lung cancer (LC) patients. In addition, the correlations between these biomarkers and the clinical outcome were analyzed using log‐rank test.

Results

Intratumoral heterogeneous expression of PD‐L1 was observed on tumor cells (TCs) in 11 cases and on immune cells (ICs) in 10 cases with BM samples from multiple regions. There was a disagreement in PD‐L1 expression on TCs between paired BM and PL lesions in 15 cases and on ICs in seven cases. Intraepithelial CD3⁺ and CD8⁺ T cell infiltration levels in BM samples were lower than those in the paired PL samples. PD‐L1 positivity on both TCs and ICs was associated with a better post‐BM‐surgery prognosis (p = 0.010; p = 0.041). Notably, PD‐L1 positivity on TCs and a high level of intraepithelial CD8⁺ T cell infiltration could serve as an integrated biomarker that indicates longer survival time (p = 0.004) in LC patients.

Conclusion

The heterogeneity in PD‐L1 expression was common in both stromal and intraepithelial regions in BM lesions of LC patients, suggesting the need for multiregional PD‐L1 testing in clinical practice. More importantly, a combination of PD‐L1 expression on TCs with intraepithelial CD8⁺ T cell infiltration might predict better post‐BM‐surgery outcomes.

High SHP2 expression determines the efficacy of PD-1/PD-L1 inhibitors in advanced KRAS mutant non-small cell lung cancer

BACKGROUND

Src homology region 2 domain-containing phosphatase 2 (SHP2) is a novel target for Kirsten rat sarcoma oncogene (KRAS) mutant cancer. We retrospectively studied the significance of SHP2 in KRAS mutant non-small cell lung cancer (NSCLC) treated with immunotherapy and its relationship with tumor microenvironment (TME).

METHODS

Sixty-one advanced KRAS mutant NSCLC patients who underwent immunotherapy were enrolled. Next-generation sequencing (NGS) was used to profile mutation status. The expression of SHP2, phospho-SHP2 (pSHP2), and programmed death ligand 1 (PD-L1) were analyzed by immunohistochemistry (IHC). Quantitative multiplexed immunofluorescence cytochemistry (mIFC) analysis was conducted to describe the TME.

RESULTS

SHP2 was heterogeneously expressed in 32 samples in both tumor cells and immune cells and highly expressed (H-score >10) in 25 (78.1%) samples. The expression levels of SHP2 and pSHP2 were positively correlated. Stromal SHP2 (s-SHP2) was higher in tumors with PD-L1 ≥50% versus PD-L1 <50% (p = 0.039). By quantitative mIFC analysis, the expression of s-SHP2 had positive correlation with CD8, CD4, CD68, and PD-L1 levels in stromal area. Patients with high SHP2 expression made up 100.0% of the partial respond (PR) and 80.0% of the stable disease (SD), whereas 50.0% of the progress disease (PD). High SHP2 expression was associated with longer progression-free survival (PFS) and overall survival (OS) (p < 0.001, p = 0.013). Patients with high expression of both SHP2 and PD-L1 had longer PFS (p < 0.001).

CONCLUSION

High SHP2 expression could predict the efficacy of immunotherapy and better survival in advanced KRAS mutant NSCLC. SHP2 may function in both tumor cells and immune cells, warranting further study on the potential diverse effects of SHP2 inhibition in TME.

[Extraction and Separation of Sinapine from Rapeseed Cake and the Mode of Action of Melanin Production Inhibition]

Brassica campestris L. is the important oil-bearing crop in China. Rapeseed cake is the main byproduct of rapeseed oil extraction. As the main active ingredient in rapeseed cake, sinapine has several important biological activities. Therefore, the inhibitory activity of sinapine on tyrosinase in vitro and its free radical-scavenging rate were determined. Tyrosinase activity in A-375 human melanocytes was also investigated and the effects of sinapine on the melanin content and its antioxidant effects on melanin biosynthesis were studied. The results showed that sinapine had significant antioxidant activity. Sinapine significantly inhibited A-375 human melanocytes in a dose-dependent manner. Sinapine inhibited melanin synthesis in A-375 cells by downregulating the mRNA and protein expression of TRP-1, TRP-2, and MITF factors. The results showed that rapeseed cake sinapine inhibited melanin production and could be used as a potential active ingredient in the development of whitening agents.

Establishment and application of a method of next generation sequencing of 285 genes in lung cancer based on Ion-Proton platform

Background

The development of “precision medicine” needs a novel genetic screening and diagnostic technique for clinical detection. This study aims to establish a method for highly parallel multiplexed detection of genetic mutations in Chinese lung cancer samples through testing 285 genes by customized next generation sequencing (NGS) on Ion-Proton platform.

Methods

We reviewed the related literature and collected data of genomic alteration that occurred in lung cancer. We identified 285 target genes closely related to the pathogenesis, drug resistance, and metastasis of lung cancer. Targeted hybridization probes were designed using SureDesign software. The detection method was established by analyzing four cell lines and 13 lung cancer specimens which had been validated through Sanger sequencing. The sensitivity and specificity of the proposed method were preliminarily evaluated by comparisons with the Sanger sequencing and a LungCarta mutation-detection method.

Results

The proposed method was able to detect mutations of 285 genes in lung cancer cell lines and clinical lung cancer specimens. The reads, mapped reads, on target, mean depth and uniformity were 14.90±4.37 (×10⁶), 98.68%±0.61%, 60.49%±10.72%, 714.42±264.13 and 90.51%±6.91%, respectively. The detected mutation result of cell lines was consistent with the observations on previously reported mutations, and the congruence rate was 100%. The proposed method can detect single nucleotide polymorphism (SNP), InDel, Fusion and copy number variation (CNV). The complete congruence rate of detected result of specimens between the proposed method and Sanger sequencing, LungCarta mutation-detection method, immunohistochemistry (IHC), real-time polymerase chain reaction (RT-PCR) method were all 100% regarding mutations in common genes like EGFR, KRAS, or fusions of ALK, RET, etc. In addition, NFE2L3_p.Ser511_Pro513del, ERBB2_E770delinsEAYVM, MET_S701N, PDGFRA_T674I, TP53_G245V, TP53_V274A, TP53_A276F, TP53_G334L, TP53_R337L and TP53_Y220C mutations were detected only through the proposed method. The proposed method can detect mutations from blood, this detection result was consistent with the cancer tissues of the same clinical lung cancer patient.

Conclusions

The proposed Ion-Proton technology-based NGS method can detect genetic mutations in Chinese lung cancer patients. Therefore, the proposed method could be used to detect mutations in other cancer tissues and plasma, which needs further validation.

Low frequency of mutation of epidermal growth factor receptor (EGFR) and arrangement of anaplastic lymphoma kinase (ALK) in primary pulmonary lymphoepithelioma-like carcinoma

Background

Primary pulmonary lymphoepithelioma‐like carcinoma (PLELC) is a rare and unique subtype of lung cancer. However, the prevalence of driver alterations, such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements, and the response of tyrosine kinase inhibitor (TKIs) in PLELC has not been thoroughly investigated.

Method

We retrospectively reviewed the genetic profiles and treatment course of 330 PLELC patients at the Guangdong Lung Cancer Institute (GLCI) from 1st January, 2008 to 30th December, 2018. We searched and analyzed related literature published in PubMed and Web of Science from 1st January, 2000 and 31th August, 2019 based on their mention of “driver mutations” and “the response of TKIs to mutant PLELC”.

Results

Genetic alterations of EGFR/ALK were tested in 203 patients (203/330, 61.5%). Five patients (5/175, 2.9%) had EGFR mutation and three patients (3/140, 2.1%) had ALK alteration. From the total of 15 articles identified from electronic searches, 1071 PLELC cases mentioned the driver mutations. EGFR mutation and ALK rearrangement were detected in 15 patients and one patient, respectively. In total, there were four EGFR/ALK mutant PLELC patients who received targeted therapy as palliative treatment at the GLCI and in the literature. However, there was disease progression in all cases one month after use of TKIs.

Conclusion

The mutation rates of EGFR and ALK were low in PLELC. EGFR and ALK TKIs showed limited response in EGFR/ALK mutant PLELC. Further studies are needed to explore other molecular targets to optimize the therapeutic strategy for PLELC.

The role of central arginine vasopressin in corticotropin releasing hormone-induced fever in rats

The purpose of the present study was to investigate the role of central arginine vasopressin (AVP) in corticotropin releasing hormone (CRH) induced fever in the rat. Guide cannulae were inserted into the third ventricle and placed over the ventral septal area (VSA). The content of arginine vasopressin in the VSA of the brain was determined by radioimmunoassay. Colon temperature was monitored in lightly restrained rats by insertion of a catheter mounted thermistor probe 5 cm in the rectum. The results demonstrated that intracerebroventricular (icv) injection of CRH increased AVP level in the VSA and the colonic temperature of the rats. Microinjection of AVP V(1) antagonist into the VSA 10 min before CRH administration significantly enhanced CRH-induced febrile response, while AVP V(1) antagonist itself did not have a significant effect on the colonic temperature. Furthermore, injection of AVP into the VSA 5 min before CRH administration (icv) suppressed the fever evoked by CRH. These findings suggest that CRH is an important factor that stimulates the release of AVP in the VSA during fever, and endogenous AVP in the VSA has an antipyretic action on the CRH-induced fever.

Experimental changes to limb muscles elicit contralateral reactions: the problem of controls

The extensor digitorum longus muscle (EDL) or soleus muscle (SOL) in rats was mechanically overloaded on one side. The muscles were (i) untreated (normal) or (ii) self- or foreign-reinnervated (leading to persisting muscle fibres) or transplanted (leading to regenerating muscle fibres). The effects of the different procedures were studied in the treated and untreated muscles on the operated side and in the untreated muscles on the contralateral side. Overloading led to an absolute increase in mass (versus control values) in the normal muscles and to a relative increase in mass (versus the lower mass after reinnervation) in the treated muscles. The mechanism underlying this gain in mass was usually a compensatory hypertrophy. Overloading was followed by transformation of fibres from fast to slow in normal muscles. In the reinnervated muscles, the fibre distribution changed in response to the new nervous input and then remained constant. The majority of the experimental procedures elicited significant muscular changes in the contralateral muscles, including hyperplasia, fibre transformation and fibre hypertrophy or atrophy. The changes are interpreted as the consequence of a general compensatory neuromuscular activity designed to maintain a symmetrical posture during walking and running. These frequent and substantial muscular changes in the unoperated muscles clearly show that the muscles of the contralateral side cannot be used as normal controls.

Antipyretic action of dexamethasone on egtazic acid-induced fever in rabbits

The purpose of the present study was to investigate whether the antipyretic effect of dexamethasone (DEX) delivered by intravenous injection (i.v.) on intracerebroventricularly (icv) administered egtazic acid-induced febrile response is relevant to the changes in cytosolic free calcium concentration of the hypothalamus. The colon temperatures were measured by a thermistor and the cytosolic free calcium concentration ([Ca2+]i) in dissociated brain cells was measured by Fura 2-AM. The results demonstrated that the pyretic action of egtazic acid (0.6 mumol, icv) was markedly inhibited by DEX (5 mg/kg, i.v.), but DEX (60-120 mumol/L) did't affect [Ca2+]i in dissociated hypothalamus cells. Actinomycin D, which interferes with gene transcription (3 nmol, icv), completely abolished the antipyretic action of DEX on egtazic acid-induced fever. These findings suggest that the antipyretic action of DEX on egtazic acid-induced fever is related to the activation of certain gene expression in the brain, but not to the changes of transmembrane calcium ion current in hypothalamus neurons.

Electron microscopic study of long-term denervated rat skeletal muscle

BACKGROUND

This study describes the ultrastructure of long-term denervated rat extensor digitorum longus and tibialis anterior muscles, with particular emphasis on understanding the cellular basis for the reduced restorative capacity of long-term denervated muscle.

METHODS

In 30 male WI/HicksCar rats, the right hindleg was denervated for periods of 1, 2, 4, 5.5, 6, 7, 12, 14, and 18 months before tissues were prepared for electron microscopy.

RESULTS

Atrophy of muscle fibers was prominent by the second month post-denervation. At this time, type II fibers showed greater atrophy than type I fibers. At further periods of denervation, atrophy of all fibers was seen; and with increasing times of denervation the muscle fibers became surrounded by dense mats of collagen fibers. Muscle spindles persisted for the duration of this study. At two and four months, satellite cells showed signs of activation, such as elongated cytoplasmic processes and an increased concentration of cytoplasmic organelles. As denervation progressed, activated satellite cells became more widely separated from their associated muscle fibers, and basal lamina material was deposited between the satellite cells and muscle fibers. Some satellite cells broke free from their muscle fibers, and others acted as bridges between two muscle fibers. Evidence was seen of both muscle fiber degeneration and the regeneration of new muscle fibers, often more than one regenerating fiber beneath a single basal lamina. Loose folds of basal lamina were often present around atrophic muscle fibers. As denervation progressed, the morphology of individual muscle fibers varied. Some contained well-ordered lattice arrays of myofilaments, whereas in others considerable sarcomeric disorganization was evident. Mitochondria became smaller and rounded; elements of the sarcoplasmic reticulum proliferated and became more disorganized; lipid droplets, glycogen deposits, and autophagic vesicles were all present in the cytoplasm of atrophic muscle fibers.

CONCLUSIONS

In addition to muscle fiber atrophy, long-term denervated muscles show evidence of myofiber and capillary death, as well as the deposition of massive amounts of interstitial collagen. These changes, all of which would appear to reduce the restorative capacity of the denervated muscle, take place concurrently with the morphological activation of satellite cells. The latter indicates that even in the denervated condition, restorative processes occur concurrently with regressive processes.

Quantitative study of the effects of long-term denervation on the extensor digitorum longus muscle of the rat

BACKGROUND

In order to understand the cellular basis underlying the progressively poorer restorative capacity of long-term denervated muscle, we determined the effects of long-term denervation on the muscle fibers and satellite cell population of the rat extensor digitorum longus (EDL) muscle.

METHODS

In 36 male rats, the right hind legs were denervated, and EDL muscles were removed 2, 4, 7, 12, and 18 months later. Muscles were either fixed for electron microscopic analysis or were dissociated into individual muscle fibers for direct fiber counting or for confocal microscopic analysis.

RESULTS

The percentage of satellite cells rose from the 2.8% control value to 9.1% at 2 months of denervation; thereafter the percentage decreased to 1.1% at 18 months of denervation. The number of myonuclei per muscle fiber steadily declined from 410 in 4 month control muscle to 158 in 7 month denervated muscle. Up to 7 months of denervation, the total number of muscle fibers per muscle remained relatively constant at somewhat over 5,000. The calculated total satellite cell population in 4 month denervated EDL muscle was the same as that of controls at 65,000, but by 7 months of denervation it had declined to 21,000. With increasing time of denervation, the number of cross-sectional profiles of muscle fibers not containing nuclei rose from 14% in control muscle to 49% in 12 month denervated muscle. This was correlated with a pronounced regular clumping of the nuclei, with pronounced nonnucleated segments between nuclear clumps.

CONCLUSIONS

Increasing times of denervation are accompanied by a pronounced decline in the number of myonuclei per muscle fiber and an initial rise and subsequent fall in satellite cell number. These changes are correlated with a decreasing restorative ability of these muscles over the same periods of denervation. Further work on the proliferative capacity of the remaining satellite cells is necessary before firm quantitative conclusions can be made.

The occurrence of post-denervation hypertrophy in chick slow muscle fibres after complete elimination of stretch and tension

With the slow muscle fibres in the pure slow muscle ALD as well as in two mixed muscles, flexor metacarpi ulnaris and sartorius, it is demonstrated that the phenomenon of postdenervation hypertrophy still occurs under conditions preventing stretch of muscle after denervation or even in tenotomized muscles in shortened state relieved of tension. Striking differences between the slow fibres of the ALD and those of the mixed muscles are seen, both with respect to their histochemical property and to the degree of development of post-denervation hypertrophy. The slow fibres in the mixed muscles show the phenomenon of post-denervation hypertrophy in a much more striking form than the ALD fibres and should be made more use of in further studies on the phenomenon.