A novel cell-based assay for the high-throughput screening of epithelial-mesenchymal transition inhibitors: Identification of approved and investigational drugs that inhibit epithelial-mesenchymal transition

OBJECTIVES

Lung cancer with distant metastases is associated with a very poor prognosis, and epithelial-mesenchymal transition (EMT) contributes to cancer metastasis. Therefore, elucidation and inhibition of EMT signaling in lung cancer may be a new therapeutic strategy for improving the prognosis of patients. We constructed a high-throughput screening system for EMT inhibitors. Using this system, we aimed to identify compounds that indeed inhibit EMT.

MATERIALS AND METHODS

We generated a luciferase reporter cell line using A549 human lung cancer cells and E-cadherin or vimentin as EMT markers. EMT was induced by transforming growth factor β1 (TGF-β1), and candidate EMT inhibitors were screened from a library of 2,350 compounds. The selected compounds were further tested using secondary assays to verify the inhibition of EMT and invasive capacity of cells.

RESULTS

Values obtained by the assay were adjusted for the number of viable cells and scored by determining the difference between mean values of the positive and negative control groups. Four compounds were identified as novel candidate drugs. Among those, one (avagacestat) and two compounds (GDC-0879 and levothyroxine) improved the expression of E-cadherin and vimentin, respectively, in epithelial cells. GDC-0879 and levothyroxine also significantly inhibited the invasive capacity of cells.

CONCLUSION

We systematically screened approved, investigational, and druggable compounds with inhibitory effects using a reporter assay, and identified candidate drugs for EMT inhibition.

Nrf2/p‑Fyn/ABCB1 axis accompanied by p‑Fyn nuclear accumulation plays pivotal roles in vinorelbine resistance in non‑small cell lung cancer

Adjuvant cisplatin‑vinorelbine is a standard therapy for stage II/III lung cancer. However, a poor survival rate of patients with lung cancer is attributed to vinorelbine resistance arising from ATP‑binding cassette (ABC) sub‑family B member 1 (ABCB1) and phosphorylated Fyn (p‑Fyn) overexpression. However, the underlying mechanisms remain unclear. NF‑E2‑related factor 2 (Nrf2) regulates the ABC family and activates the nuclear transport of Fyn. The present study evaluated the roles of the Nrf2/p‑Fyn/ABCB1 axis in vinorelbine‑resistant (VR) cells and clinical samples. To establish VR cells, H1299 cells were exposed to vinorelbine, and the intracellular reactive oxygen species (ROS) level in the H1299 cells was determined using a DCFH‑DA assay. The total and subcellular expression of Nrf2, ABCB1 and p‑Fyn in VR cells was evaluated. Immunofluorescence was used to detect the subcellular localization of p‑Fyn in VR cells. A cell viability assay was used to examine whether the sensitivity of VR cells to vinorelbine is dependent on Nrf2 activity. Immunohistochemistry was performed on 104 tissue samples from patients with lung cancer who underwent surgery followed by cisplatin‑vinorelbine treatment. The results revealed that persistent exposure to vinorelbine induced intracellular ROS formation in H1299 cells. p‑Fyn was localized in the nucleus, and ABCB1 and Nrf2 were overexpressed in VR cells. ABCB1 expression was dependent on Nrf2 downstream activation. The decreased expression of Nrf2 restored the sensitivity of VR cells to vinorelbine. In the surgical samples, Nrf2 and ABCB1 were associated with disease‑free survival, and p‑Fyn was associated with overall survival (P<0.05). On the whole, the present study demonstrates that Nrf2 upregulates ABCB1 and, accompanied by the nuclear accumulation of p‑Fyn, induces vinorelbine resistance. These findings may facilitate the development of drug resistance prevention strategies or new drug targets against non‑small cell lung cancer.

Abstract 6075: ROS-Nrf2-ABCB1 axis accompanied with pFyn nuclear accumulation plays pivotal roles in vinorelbine resistance in non-small cell lung cancer

Introduction: Adjuvant cisplatin-vinorelbine is standard therapy for stage II/III lung cancer. Poor survival in lung cancer can be attributed to vinorelbine resistance arising from ABC sub-family B member 1 (ABCB1) and phosphorylated Fyn (pFyn) overexpression. However, the underlying mechanism remains unclear. Nrf2 regulates the cell-protective ABC family and activates nuclear transport of Fyn. Here, we aimed to evaluate the ROS-Nrf2-ABCB1 axis in both vinorelbine-resistant (VR) cells and clinical samples.

Methods: We established VR cells by exposing H1299 cells to vinorelbine, and determined intracellular reactive oxygen species (ROS) level of H1299 cells induced by vinorelbine using DCFH-DA. We evaluated the total and subcellular expression of Nrf2, ABCB1, and pFyn in VR cells and performed immunofluorescence of VR cells to confirm the precise subcellular localization of pFyn. Cell viability assay was used to examine whether the sensitivity of VR cells to vinorelbine depends on Nrf2 activity. For immunohistochemistry, we used 104 tissue samples from lung cancer patients who underwent surgery followed by cisplatin-vinorelbine treatment between December 2006 and June 2018.

Results: Persistent exposure to vinorelbine induced intracellular ROS formation of H1299 cells. Both ABCB1 and Nrf2 were overexpressed in VR cells, and ABCB1 expression was dependent on Nrf2 downstream activation. Subcellular fractionation and immunofluorescence revealed nuclear accumulation of pFyn in VR cells. Decreased expression of Nrf2 restored the sensitivity of VR cells to vinorelbine. In the 104 surgical samples, Nrf2 and ABCB1 were significantly associated with disease-free survival (p = 0.029 and 0.035, respectively), and pFyn was associated with overall survival (p = 0.040).

Conclusions: ROS-Nrf2 upregulates ABCB1 and accompanied by nuclear accumulation of pFyn, induces vinorelbine resistance. Our findings may facilitate drug resistance prevention strategies or new drug target development against non-small cell lung cancer.

Citation Format: Shigeyuki Tamari, Toshi Menju, Toshiya Toyazaki, Hideaki Miyamoto, Naohisa Chiba, Misa Noguchi, Hiroshi Date. ROS-Nrf2-ABCB1 axis accompanied with pFyn nuclear accumulation plays pivotal roles in vinorelbine resistance in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6075.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors as a first-line treatment for postoperative recurrent and EGFR-mutated non-small-cell lung cancer

 

OBJECTIVES

To clarify survival outcomes and prognostic factors of patients receiving epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitors (TKIs) as first-line treatment for postoperative recurrence.

METHODS

A retrospective chart review was performed to identify consecutive patients who received EGFR-TKIs as first-line treatment for postoperative recurrence of non-small-cell lung cancer (NSCLC) harbouring EGFR gene mutations at our institution between August 2002 and October 2020. Therapeutic response, adverse events, progression-free survival (PFS) and overall survival (OS) were investigated. Survival outcomes were assessed using the Kaplan–Meier analysis. The Cox proportional hazards model was used for univariable and multivariable analyses.

RESULTS

Sixty-four patients were included in the study. The objective response and disease control rates were 53% and 92%, respectively. Grade 3 or greater adverse events were noted in 4 (6.3%) patients, including 1 patient (1.6%) of interstitial pneumonia. The median follow-up period was 28.5 months (range 3–202 months). The total number of events was 43 for PFS and 23 for OS, respectively. The median PFS was 18 months, and the median OS was 61 months after EGFR-TKI treatment. In multivariable analysis, osimertinib showed a tendency to prolong PFS [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.12–1.1; P = 0.071], whereas the micropapillary component was significantly associated with shorter OS (HR 2.1, 95% CI 1.02–6.9; P = 0.045).

CONCLUSIONS

EGFR-TKIs as first-line treatment appeared to be a reasonable treatment option in selected patients with postoperative recurrent EGFR-mutated NSCLC. Osimertinib and the micropapillary component may be prognostic factors.

Evaluation of regenerated tracheal cilia function on a collagen-conjugated scaffold in a canine model

OBJECTIVES

It is unclear whether the movement and function of the regenerated cilia on collagen-conjugated artificial trachea are the same as those of normal cilia. This study assessed the ciliary beat frequency (CBF) and ciliary transport functions (CTFs) of regenerated cilia in a canine model.

METHODS

A tracheal defect introduced into the anterior portion of the cervical trachea of an adult beagle dog was covered with a collagen-conjugated prosthesis. Two months later, the trachea was harvested along the long axis, both from normal and regenerated regions. The cilia were stained with isothiocyanate-conjugated wheat germ agglutinin, and their movement was monitored with a high-speed camera to analyse CBF and CTF. Four samples each were obtained from the regenerated and normal regions for CBF analysis and 7 samples each were obtained for CTF analysis.

RESULTS

The wheat germ agglutinin-stained cells showed well-regulated beats in both the regenerated and normal regions of the trachea. Mean CBF in the regenerated and normal regions did not differ significantly (7.11 ± 0.41 vs 7.14 ± 1.09 Hz; P = 981). By contrast, CTF was significantly lower in the regenerated region than in the normal region (30.0 ± 6.62 vs 7.43 ± 0.58 μm/s; P = 0.005).

CONCLUSIONS

Mean CBF in the regenerated and normal regions did not differ significantly at 2 months. The CTF in the regenerated region recovered partially but remained lower than those in the normal region. Methods are needed to improve the CTF of regenerated cilia.

Bilateral Trans-Septal Approach to Right Lung Cancer Invading the Left Atrium

We describe a 69-year-old woman with primary lung cancer in the right lower lobe invasive to the left atrium (LA) via the pulmonary vein (PV). The tumor in the LA measured 30 × 26 mm, and to avoid critical embolism preoperative induction therapy was not performed. The patient underwent right thoracotomy under cardiopulmonary bypass (CPB), and the atrial septum was incised via the right atrium. The tumor was placed out of the LA, followed by lobectomy. For right lung tumors invading the LA, the bilateral trans-septal approach is useful for confirming the surgical margin.

Skin marking with computed tomography at functional residual capacity to predict lung nodule site

Various marking techniques for lung nodules may be complex and can cause serious complications. In this study, we aimed to describe and evaluate the feasibility of CTFRC marking, a novel preoperative skin marking technique guided by computed tomography (CT) at functional residual capacity (FRC). This simple and non-invasive marking technique only requires a preoperative CT scan without any anaesthesia. We retrospectively reviewed CTFRC markings performed for 109 lung nodules in 108 patients. The mean nodule size was 11.4 ± 5.0 mm. The mean distance from the nodule to the lung marking point was 3.8 ± 7.3 mm. We found no procedure-associated complications. CTFRC marking is a simple, safe and non-invasive method to predict the precise location of lung nodules during thoracoscopic surgery.

Successful treatment of late onset empyema after extrapleural pneumonectomy: A case report

Treatment of post-extrapleural pneumonectomy empyema (PEPPE) is more difficult than that for post-pneumonectomy empyema for two reasons: first, a large infectious dead space remains after extrapleural pneumonectomy (EPP); and second, defects of the pericardium and diaphragm are reconstructed with artificial materials, which ideally should be removed for treatment of infection. Here, we report the case of a 56-year-old male with PEPPE that occurred long after EPP for mesothelioma. The patient was treated successfully by minimally invasive procedures of irrigation, instillation of urokinase and antibiotics, and surgical debridement without peeling off artificial materials.

Pulmonary vein thrombosis after lobectomy with vein stump closure by ligation

Objectives Thrombosis in the pulmonary vein stump after a left upper lobectomy is a rare but potentially life-threatening complication, and the pulmonary vein stump length plays an important role here. We assessed the frequency and risk factors for thrombosis in patients undergoing lobectomy with division of the superior pulmonary vein using ligation. Methods We retrospectively reviewed 425 patients with primary lung cancer who underwent lobectomy or bilobectomy in our institution from 2008 to 2016, with contrast-enhanced chest computed tomography within a year after lobectomy. The superior pulmonary vein was divided by thread ligation, while the inferior pulmonary vein was divided using a linear stapler. The pulmonary vein stump length was measured using contrast-enhanced chest computed tomography. Results Four (0.9%) of the 425 patients experienced thrombosis in the pulmonary vein stump within 6 months after lobectomy. All 4 patients had undergone a left upper lobectomy, and 4.1% of this subset developed thrombus. One patient with a thrombus in the pulmonary vein stump experienced renal and cerebral infarction after a left upper lobectomy. The left superior pulmonary vein stump was significantly longer than the other pulmonary vein stumps. Conclusions Thrombosis in the pulmonary vein stump occurred in 4.1% of patients undergoing a left upper lobectomy with pulmonary vein stump closure by thread ligation, which is a relatively low frequency. Superior pulmonary vein stump closure using thread ligation might help prevent pulmonary vein stump thrombus after a left upper lobectomy.

[Clinical characteristics after surgery of non-small cell lung cancer which measures 20 mm or less in diameter]

Today's advances in diagnostic image-technologies often enable us to find small lung cancers. However, we have few definite strategies including how to diagnosis and treat them. In this study, we performed a retrospective analysis of 122 consecutive patients who underwent surgery for non-small cell lung cancer 20 mm or less in diameter to clarify the clinical features of small lung cancer. Of 122 patients, there were 114 patients of pN0, and 8 patients with lymph node metastasis. Seventy three patients underwent lobectomy, 45 underwent segmentectomy, and 4 underwent wedge resection based on the findings of preoperative CT and anatomical and oncological view during operation. Overall survival rate( OS) and progression free survival( PFS) at 3-year was, 94% and 84%, respectively. There were no differences in OS or PFS between lobectomy group and limited resection group, which might suggest that we adapted appropriate surgical procedures. Multivariate analysis revealed that pathological pleural invasion, lymphatic vessel invasion, and vascular vessel invasion were likely to be unfavorable prognostic-factors. We believe that further investigations should be required to clarify the characteristics of small lung cancer.

[Surgery for emphysematous giant bullae]

We address 3 important keys to obtain successful outcomes in surgery for emphysematous giant bullae. It is the 1st step to select patients who might benefit from bullectomy based on functional imaging. The chest computed tomography (CT) and pulmonary perfusion scintigram provide information regarding with pulmonary vascular beds which could be recruited by bullectomy. In addition, dynamic-magnetic resonance imaging (MRI) during breathing can show a patient with paradoxical inflation of giant bulla during expiration, which means impairment of ventilation of the adjacent normal parenchyma, and is a promising sign for successful outcome of bullectomy. Second, it should be emphasized to perform a proper procedure in bullectomy. If a giant bulla has a wide bottom, it should be recommended to open the bulla and to plicate it by sutures without injury of vessels on the bottom of the bulla rather than simple bullectomy with staples. Finally, it is important to keep inflated lung avoiding atelectasis following operation by minimum pressure of suction. We show here sequential bullectomies on a 41-year-old male with chronic obstructive pulmonary disease (COPD) GOLD IV due to bilateral giant bullae and poor vascular reserve, and address our strategy described above.

Fertility of Palestinian women between national perspective and social reality

"This paper investigates the social content of fertility patterns in four Palestinian conglomerations, viz., the West Bank, Gaza Strip, Galilee and Jerusalem, on the basis of an analysis of fertility data derived from official sources and field work conducted by Palestinian demographers. It seeks to identify meaningful relationships between these data and variables related to the household's place of residence, social class, and vocational and educational background. The paper also reviews the demographic history of Arab citizens in the occupied territories since 1948 to determine the effect on fertility trends.... The paper finally touches on the impact of the Palestinian intifada...."