An Asymptomatic Sigmoid Colonic Fistula Arising from a Large Aneurysm of the Internal Iliac Artery Was Discovered during a Medical Examination.

The rupture of an internal iliac artery aneurysm in the colon is a rare but potentially fatal complication. We report a rectal fistula of an asymptomatic internal iliac artery aneurysm that was discovered incidentally during a medical examination. A 77-year-old man presented at a local hospital for a general medical examination. Although the blood reports revealed severe anemia, the patient did not complain of any associated symptoms including dizziness and hematochezia. Moreover, there was no palpable mass in the patient's abdomen, and there was no evidence of hematochezia, as the patient had been using a bidet. Interestingly, computed tomography (CT) revealed a large right internal iliac artery aneurysm. There was a suspicious finding of a fistula within the colon in the CT, but it was undetected in the preoperative sigmoidoscopy. Furthermore, operative findings showed a protruding retroperitoneal mass adhering to the mesentery of the sigmoid colon. During aneurysm resection, the presence of a fistula was unclear. However, a fistula tract, devoid of any infectious bacteria such as tuberculosis, was found in the specimen after colon resection. After a recovery period of approximately one week, the patient was discharged from the hospital without any unusual findings on the post-operative CT. Sigmoid colonic fistulas arising from iliac artery aneurysms are rare. Also, diagnosis may be delayed in special circumstances wherein a patient routinely uses a bidet.

Critical Hemorrhage Caused by a Size-Mismatched Extracorporeal Membrane Oxygenation Cannula in a Patient with Myotonic Dystrophy Type 1: A Case Report and Literature Review.

Background and Objective: Although extracorporeal membrane oxygenation (ECMO) is an essential life-saving technique for patients with refractory cardiopulmonary shock, it can be fatal in certain cases. Case Presentation: A 19-year-old girl treated with ECMO presented with acute limb ischemia 2 days after cannula removal. The decannulation was performed percutaneously by an interventional cardiologist, and the vascular surgery department was consulted after the patient developed symptoms. The first suspected diagnosis was thrombosis due to incorrect use of the closure device. However, the artery had ruptured due to the insertion of a catheter with a cannula that was larger than the patient's artery. Management and Outcome: Fortunately, excessive bleeding due to the size-mismatched cannula was prevented by an unintentional complication of the closing device, which saved the patient's life. She underwent a right common femoral artery thrombectomy and patch angioplasty. Hospital guidelines have changed regarding the surgical removal of ECMO cannulas. Discussion: This report aims to highlight the importance of two aspects that are critical to a successful outcome: individualized cannula selection followed by precise insertion and removal and postoperative evaluation of a patient's final status.

Gastric Metastasis Mimicking Early Gastric Cancer from Invasive Ductal Carcinoma of the Breast: Case Report and Literature Review.

Backgound and Objectives: Gastric metastasis from invasive ductal breast cancer (BC) is rare. It mainly occurs in patients with lobular BC. The occurrence of multiple metastases is typically observed several years after the primary diagnosis. Endoscopic findings of gastric metastasis of the BC were usually the linitis plastic type. Case presentation: A 72-year-old women who underwent right modified radical mastectomy (MRM) 10 month ago was referred after being diagnosed with early gastric cancer (EGC) during systemic chemotherapy. EGC type I was found at gastric fundus, and pathologic finding showed poorly differentiated adenocarcinoma. Metachronous double primary tumor EGC was considered. Management and Outcome: A laparoscopic total gastrectomy was performed, and postoperative pathology revealed submucosa invasion and two lymph node metastases. A pathologic review that focused on immunohistochemical studies of selected antibodies such as GATA binding protein 3 (GATA3), gross cystic disease fluid protein-15 (GCDFP-15), cytokeratin 7 (CK7) was performed again, comparing previous results. As a result, gastric metastasis from BC was diagnosed. After totally laparoscopic total gastrectomy, palliative first-line chemotherapy with paclitaxel/CDDP was performed. Two months after gastrectomy, she was diagnosed with para-aortic lymph node metastasis and multiple bone metastases. She expired six months after gastrectomy. Conclusions: Gastric metastasis from invasive ductal carcinoma of the breast, which is clinically manifested as EGC, is a very rare condition. If there is a history of BC, careful pathological review will be required.

Rupture of Mycotic Abdominal Aortic Aneurysm as a Result of Incompletely Treated Multiple Peripheral Mycotic Aneurysms.

Background: A mycotic aortic aneurysm is a rare type of aortic aneurysm that can have disastrous outcomes. Most mycotic aneurysms originate from infectious sources, such as trauma, vegetation in the heart, and adjacent infectious sources. If a mycotic aneurysm is diagnosed, it should be treated simultaneously with the primary source of the infection. Case Summary: Treatment was performed for a mycotic aneurysm of the brachial artery that occurred suddenly during treatment for a fever for which the primary source of infection had not been confirmed. The workup revealed that a mycotic aneurysm of the brachial artery was the cause of the fever, followed by aneurysms in the abdomen and lower extremities and even vegetation in the heart that was not initially present. The patient declined to undergo treatment for personal reasons. After 5 months, it was revealed that the abdominal aortic aneurysm, which was initially considered normal aorta, was ruptured; however, the aneurysm was successfully treated. Conclusions: A peripheral mycotic aneurysm may be associated with multiple aneurysms. Appropriate diagnosis and complete treatments are necessary to prevent fatal consequences.

ASOptimizer: Optimizing antisense oligonucleotides through deep learning for IDO1 gene regulation.

Recent studies have highlighted the effectiveness of using antisense oligonucleotides (ASOs) for cellular RNA regulation, including targets that are considered undruggable; however, manually designing optimal ASO sequences can be labor intensive and time consuming, which potentially limits their broader application. To address this challenge, we introduce a platform, the ASOptimizer, a deep-learning-based framework that efficiently designs ASOs at a low cost. This platform not only selects the most efficient mRNA target sites but also optimizes the chemical modifications for enhanced performance. Indoleamine 2,3-dioxygenase 1 (IDO1) promotes cancer survival by depleting tryptophan and producing kynurenine, leading to immunosuppression through the aryl-hydrocarbon receptor (Ahr) pathway within the tumor microenvironment. We used ASOptimizer to identify ASOs that target IDO1 mRNA as potential cancer therapeutics. Our methodology consists of two stages: sequence engineering and chemical engineering. During the sequence-engineering stage, we optimized and predicted ASO sequences that could target IDO1 mRNA efficiently. In the chemical-engineering stage, we further refined these ASOs to enhance their inhibitory activity while reducing their potential cytotoxicity. In conclusion, our research demonstrates the potential of ASOptimizer for identifying ASOs with improved efficacy and safety.

Invasive FoxM1 phosphorylated by PLK1 induces the polarization of tumor-associated macrophages to promote immune escape and metastasis, amplified by IFITM1.

BACKGROUND: Understanding the mechanism behind immune cell plasticity in cancer metastasis is crucial for identifying key regulators. Previously we found that mitotic factors regulate epithelial-mesenchymal transition, but how these factors convert to metastatic players in the tumor microenvironment (TME) is not fully understood. METHODS: The clinical importance of mitotic factors was analyzed by heatmap analysis, a KM plot, and immunohistochemistry in lung adenocarcinoma (LUAD) patients. Immunoprecipitation, LC-MS/MS, kinase assay, and site-directed mutagenesis were performed for the interaction and phosphorylation. A tail-vein injection mouse model, Transwell-based 3D culture, microarray analysis, coculture with monocytes, and chromatin immunoprecipitation assays were used to elucidate the function of phosphorylated FoxM1 in metastasis of TME. RESULTS: The phosphorylated FoxM1 at Ser25 by PLK1 acquires the reprogramming ability to stimulate the invasive traits in cancer and influence immune cell plasticity. This invasive form of p-FoxM1 upregulates the expression of IL1A/1B, VEGFA, and IL6 by direct activation, recruiting monocytes and promoting the polarization of M2d-like tumor-associated macrophages (TAMs). Upregulation of PD-L1 in LUAD having phosphomimetic FoxM1 facilitates immune evasion. In invasive LUAD with phosphomimetic FoxM1, IFITM1 is the most highly expressed through the activation of the STING-TBK1-IRF3 signaling, which enhances FoxM1-mediated signaling. Clinically, higher expression of FOXM1, PLK1, and IFITM1 is inversely correlated with the survival rate of advanced LUAD patients, providing a promising therapeutic strategy for the treatment of LUAD. CONCLUSION: FoxM1-based therapy would be a potential therapeutic strategy for LUAD to reduce TAM polarization, immune escape, and metastasis, since FoxM1 functions as a genetic reprogramming factor reinforcing LUAD malignancy in the TME.

Vasomotion in human arteries and their regulations based on ion channel regulations: 10 years study.

Vasomotion is the oscillation of vascular tone which gives rise to flow motion of blood into an organ. As is well known, spontaneous contractile organs such as heart, GI, and genitourinary tract produce rhythmic contraction. It imposes or removes pressure on their vessels alternatively for exchange of many substances. It was first described over 150 years ago, however the physiological mechanism and pathophysiological implications are not well understood. This study aimed to elucidate underlying mechanisms and physiological function of vasomotion in human arteries. Conventional contractile force measurement, immunohistochemistry, and Western blot analysis were employed to study human left gastric artery (HLGA) and uterine arteries (HUA). RESULTS: Circular muscle of HLGA and/or HUA produced sustained tonic contraction by high K+ (50 mM) which was blocked by 2 µM nifedipine. Stepwise stretch and high K+ produced nerve-independent spontaneous contraction (vasomotion) (around 45% of tested tissues). Vasomotion was also produced by application of BayK 8644, 5-HT, prostagrandins, oxytocin. It was blocked by nifedipine (2 µM) and blockers of intracellular Ca2+ stores. Inhibitors of Ca2+ -activated Cl- channels (DIDS and/or niflumic acid) and ATP-sensitive K+ (KATP ) channels inhibited vasomotion reversibly. Metabolic inhibition by sodium cyanide (NaCN) and several neuropeptides also regulated vasomotion in KATP channel-sensitive and -insensitive manner. Finally, we identified TMEM16A Ca2+ -activated Cl- channels and subunits of KATP channels (Kir 6.1/6.2 and sulfonylurea receptor 2B [SUR2B]), and c-Kit positivity by Western blot analysis. We conclude that vasomotion is sensitive to TMEM16A Ca2+ -activated Cl- channels and metabolic changes in human gastric and uterine arteries. Vasomotion might play an important role in the regulation of microcirculation dynamics even in pacemaker-related autonomic contractile organs in humans.

The microRNA-485-3p concentration in salivary exosome-enriched extracellular vesicles is related to amyloid ß deposition in the brain of patients with Alzheimer's disease.

OBJECTIVES: Alzheimer's disease (AD) is an irreversible neurodegenerative disease characterized by progressive long-term memory loss and cognitive dysfunction. Neuroimaging tests for abnormal amyloid-ß (Aß) deposition are considered the most reliable methods for the diagnosis of AD; however, the cost for such testing is very high and generally not covered by national insurance systems. Accordingly, it is only recommended for individuals exhibiting clinical symptoms of AD supported by clinical cognitive assessments. Recently, it was suggested that dysregulated microRNA-485-3p (miRNA-485-3p) in the brain and cerebrospinal fluid is closely related to pathogenesis of AD. However, a relationship between circulating miRNA-485-3p in salivary exosome-enriched extracellular vesicles (EE-EV) and Aß deposition in the brain has not been observed. DESIGN & METHODS: Using quantitative real-time polymerase chain reaction, we analyzed miRNA-485-3p concentration in salivary EE-EV. We used receiver operating characteristic (ROC) curve analysis to evaluate its predictive value for Aß positron emission tomography (Aß-PET) positivity in patients with AD. RESULTS: Our results showed that the miRNA-485-3p concentration in salivary EE-EV isolated from patients with AD was significantly increased compared with that in the healthy controls (p < 0.0001). In the analysis of all participants, the miRNA-485-3p concentration was significantly increased in Aß-PET-positive participants compared to Aß-PET-negative participants (p < 0.0001). Further analysis using only AD patients also showed that the miRNA-485-3p concentration was significantly increased in Aß-PET-positive AD patients vs. Aß-PET-negative AD patients (p = 0.0063). The ROC curve analysis for differentiating Aß-PET-positive and negative participants showed that the area under the curve for miRNA-485-3p was 0.9217. CONCLUSION: These findings suggested that the miRNA-485-3p concentration in salivary EE-EV was closely related to Aß deposition in the brain and had high diagnostic accuracy for predicting Aß-PET positivity.

A splinkerette PCR-based genome walking technique for the identification of transgene integration sites in CHO cells.

Identification of recombinant gene integrations sites in the Chinese hamster ovary (CHO) cell genome is increasingly important to assure monoclonality. While next-generation sequencing (NGS) is commonly used for the gene integration site analysis, it is a time-consuming and costly technique as it analyzes the entire genome. Hence, simple, easy, and inexpensive methods to analyze transgene insertion sites are necessary. To selectively capture the integration site of transgene in the CHO genome, we applied splinkerette-PCR (spPCR). SpPCR is an adaptor ligation-based method using splinkerette adaptors that have a stable hairpin loop. Restriction enzymes with high frequencies in the CHO genome were chosen using a Python script and used for the in vitro spPCR assay development. After testing on two CHO housekeeping genes with known loci, the spPCR-based genome walking technique was successfully applied to recombinant CHO cells to identify the transgene integration site. Finally, the comparison with NGS methods exhibited that the time and cost required for the analysis can be substantially reduced. Taken together, the established technique would aid the stable cell line development process by providing a rapid and cost-effective method for transgene integration site analysis.

The Integration of Reference Electrode for ISFET Ion Sensors Using Fluorothiophenol-Treated rGO.

Ion-sensitive field-effect transistors (ISFETs) detect specific ions in solutions that enable straightforward, fast, and inexpensive sensors compared to other benchtop equipment. However, a conventional reference electrode (RE) such as Ag/AgCl is limited on the miniaturization of the sensor. We introduce reduced graphene oxide (rGO), which serves as a new RE, when fluorinated (F-rGO) using fluorothiophenol through the π-π interaction. The circular RE is integrated between a fabricated microscale two-channel ISFET, which is capable of detecting two kinds of ions on an indium tin oxide (ITO) thin-film substrate, using the photolithography process. F-rGO bound to this circular region to function as an RE in the ISFETs sensor, which operated stably in solution and showed a relatively high transconductance (gm) value (1.27 mS), low drift characteristic (3.2 mV), and low hysteresis voltage (±0.05 mV). It detected proton (H+) ions in a buffer solution with high sensitivity (67.1 mV/pH). We successfully detected Na+ (62.1 mV/dec) and K+ (57.6 mV/dec) ions in human patient urine using a two-channel ISFET with the F-rGO RE. The F-rGO RE will be a suitable component in the fabrication of low-cost, mass-produced, and disposable ISFETs sensors.

The role of microRNA-485 in neurodegenerative diseases.

Neurodegenerative diseases (NDDs) are age-related disorders characterized by progressive neurodegeneration and neuronal cell loss in the central nervous system. Neuropathological conditions such as the accumulation of misfolded proteins can cause neuroinflammation, apoptosis, and synaptic dysfunction in the brain, leading to the development of NDDs including Alzheimer's disease (AD) and Parkinson's disease (PD). MicroRNAs (miRNAs) are small noncoding RNA molecules that regulate gene expression post-transcriptionally via RNA interference. Recently, some studies have reported that some miRNAs play an important role in the development of NDDs by regulating target gene expression. MiRNA-485 (miR-485) is a highly conserved brain-enriched miRNA. Accumulating clinical reports suggest that dysregulated miR-485 may be involved in the pathogenesis of AD and PD. Emerging studies have also shown that miR-485 plays a novel role in the regulation of neuroinflammation, apoptosis, and synaptic function in the pathogenesis of NDDs. In this review, we introduce the biological characteristics of miR-485, provide clinical evidence of the dysregulated miR-485 in NDDs, novel roles of miR-485 in neuropathological events, and discuss the potential of targeting miR-485 as a diagnostic and therapeutic marker for NDDs.

Plk2-mediated phosphorylation and translocalization of Nrf2 activates anti-inflammation through p53/Plk2/p21cip1 signaling in acute kidney injury.

The Plk2 is a cellular stress-responsive factor that is induced in response to oxidative stress. However, the roles of Plk2 in acute kidney injury (AKI) have not been clarified. We previously found that Plk2 is an interacting factor of Nrf2 in response to cellular stress, since Plk2 is upregulated in the Nrf2-dependent network. Here, we show that the levels of p53, Plk2, p21cip1, and chromatin-bound Nrf2 were all upregulated in kidney tissues of mice or NRK52E cells treated with either cisplatin or methotrexate. Upregulation of Plk2 by p53 led to an increase of Nrf2 in both soluble and chromatin fractions in cisplatin-treated NRK52E cells. Consistently, depletion of Plk2 suppressed the levels of Nrf2. Of note, Plk2 directly phosphorylated Nrf2 at Ser40, which facilitated its interaction with p21cip1 and translocation into the nuclei for the activation of anti-oxidative and anti-inflammatory factors in response to AKI. Together, these findings suggest that Plk2 may serve as an anti-oxidative and anti-inflammatory regulator through the phosphorylation and activation of Nrf2 to protect kidney cells from kidney toxicants and that Plk2 and Nrf2 therefore work cooperatively for the protection and survival of kidney cells from harmful stresses.

Clinical significance of the number of retrieved lymph nodes in early gastric cancer with submucosal invasion.

The prognosis of early gastric cancer (EGC) with submucosal invasion is favorable; however, several cases of recurrence have been reported even after curative gastrectomy. This study aimed to investigate risk factors and evaluate the clinical significance of the number of retrieved lymph nodes (LNs) in EGC with submucosal invasion. We retrospectively analyzed the data of 443 patients with gastric cancer with submucosal invasion after curative gastrectomy for recurrent risk factors. Recurrence was observed in 22 of the 443 gastric cancer patients with submucosal invasion. In the univariate analysis, the risk factors for recurrence were the number of retrieved LNs ≤ 25 and node metastasis. In the multivariate analysis, retrieved LNs ≤ 25 (hazard ratio [HR] = 5.754, P-value = .001) and node metastasis (HR = 3.031, P-value = .029) were independent risk factors for recurrence after curative gastrectomy. Body mass index was related to retrieved LNs ≤ 25 in univariate and multivariate analyses (HR = .510, P = .002). The number of retrieved LNs and node metastases were independent risk factors for EGC with submucosal invasion. For EGC with submucosal invasion, retrieved LNs > 25 are necessary for appropriate diagnosis and treatment.

Clinical impact of surgical treatment for the spontaneously ruptured resectable hepatocellular carcinoma: A single institution experience.

Spontaneously ruptured hepatocellular carcinoma (srHCC) is a fatal complication of hepatocellular carcinoma (HCC). In addition, emergency treatment is frequently fraught with difficulties. This study aimed to investigate the prognosis and recurrence pattern in patients undergoing hepatectomy for the srHCC. This retrospective study included 11 patients with srHCC treated using either emergency hepatectomy or emergency transarterial embolization (TAE) followed by staged hepatectomy between January 2015 and December 2019. The patients visited the emergency room because of a sudden rupture of HCC without being diagnosed with HCC. We analyzed the prognosis, recurrence rate, and survival in these patients after hepatectomy. Four of the 11 patients in this study were classified as Child-Pugh class A and 7 as Child-Pugh class B. Nine patients visited for sudden onset of abdominal pain, and 2 for sudden onset of shock. The median hemoglobin level at the time of the visit was 11.5 g/dL (interquartile range: 9.8-12.7). Five patients underwent one-stage hepatectomy and 6 underwent emergency TAE hemostasis followed by staged hepatectomy. Median overall survival and recurrence-free survivals were 23 and 15 months, respectively. Recurrence occurred in 7 patients (4 in the one-stage group and 3 in the staged group). Among patients with recurrence, 6 had intrahepatic recurrence and 3 peritoneal metastases. Patients with srHCC who undergo staged hepatectomy can achieve a relatively good prognosis. The most common sites of recurrence after hepatectomy are intrahepatic and peritoneal. Peritoneal metastases are more likely to occur after one-stage hepatectomy.

Delayed duodenal stump fistula after laparoscopic distal gastrectomy with Billroth-II reconstruction for early gastric cancer: A case report.

Duodenal stump fistula (DSF) is one of the most serious complications of gastrectomy. The mean time to diagnosis of DSF is approximately 9 days after operation. Our report describes an extremely rare case of delayed DSF 144 days after a laparoscopic distal gastrectomy. A 58-year-old man with drug-induced liver cirrhosis (Child-Pugh class A) underwent laparoscopic distal gastrectomy with Billroth-II reconstruction for early gastric cancer. On postoperative day 1, he underwent reoperation because of intra-abdominal bleeding. Ongoing bleeding was observed in the stapler line of the duodenal stump and was controlled using metallic surgical clips. The patient was discharged on postoperative day 14, without complications. After 144 days following the first operation, he visited the emergency room with right flank pain and high fever. Computed tomography revealed free air and abscess near the duodenal stump site. Emergency laparotomy, abscess unlooping, and drain insertion were performed. After surgery, bile was drained by intra-abdominal drainage, and fistulography showed a duodenal fistula. The patient was discharged 55 days after his third surgery. This is an extremely rare case of DSF, which may be caused by the metallic surgical clips used for hemostasis of the duodenal stump stapler line. We believe that the use of metallic surgical clips for hemostasis of the duodenal stump after Billroth-II reconstruction should be avoided.

The effect of long working hours on developing type 2 diabetes in adults with prediabetes: The Kangbuk Samsung Cohort Study.

Background: Long working hours are known to account for approximately one-third of the total expected work-related diseases, and much interest and research on long working hours have recently been conducted. Additionally, as the prevalence of prediabetes and the high-risk group for diabetes are increasing worldwide, interest in prediabetes is also rising. However, few studies have addressed the development of type 2 diabetes and long working hours in prediabetes. Therefore, the aim of this longitudinal study was to evaluate the relationship between long working hours and the development of diabetes in prediabetes. Methods: We included 14,258 prediabetes participants with hemoglobinA1c (HbA1c) level of 5.7 to 6.4 in the Kangbuk Samsung Cohort Study. According to a self-reported questionnaire, we evaluated weekly working hours, which were categorized into 35-40, 41-52, and > 52 hours. Development of diabetes was defined as an HbA1c level ≥ 6.5%. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the development of diabetes were estimated using Cox proportional hazards analyses with weekly working 35-40 hours as the reference. Results: During a median follow-up of 3.0 years, 776 participants developed diabetes (incidence density, 1.66 per 100 person-years). Multivariable-adjusted HRs of development of diabetes for weekly working > 52 hours compared with working 35-40 hours were 2.00 (95% CI: 1.50-2.67). In subgroup analyses by age (< 40 years old, ≥ 40 years old), sex (men, women), and household income (< 6 million KRW, ≥ 6 million KRW), consistent and significant positive associations were observed in all groups. Conclusions: In our large-scale longitudinal study, long working hours increases the risk of developing diabetes in prediabetes patients.

Mitotic protein kinase-driven crosstalk of machineries for mitosis and metastasis.

Accumulating evidence indicates that mitotic protein kinases are involved in metastatic migration as well as tumorigenesis. Protein kinases and cytoskeletal proteins play a role in the efficient release of metastatic cells from a tumor mass in the tumor microenvironment, in addition to playing roles in mitosis. Mitotic protein kinases, including Polo-like kinase 1 (PLK1) and Aurora kinases, have been shown to be involved in metastasis in addition to cell proliferation and tumorigenesis, depending on the phosphorylation status and cellular context. Although the genetic programs underlying mitosis and metastasis are different, the same protein kinases and cytoskeletal proteins can participate in both mitosis and cell migration/invasion, resulting in migratory tumors. Cytoskeletal remodeling supports several cellular events, including cell division, movement, and migration. Thus, understanding the contributions of cytoskeletal proteins to the processes of cell division and metastatic motility is crucial for developing efficient therapeutic tools to treat cancer metastases. Here, we identify mitotic kinases that function in cancer metastasis as well as tumorigenesis. Several mitotic kinases, namely, PLK1, Aurora kinases, Rho-associated protein kinase 1, and integrin-linked kinase, are considered in this review, as an understanding of the shared machineries between mitosis and metastasis could be helpful for developing new strategies to treat cancer.

Dual Targeting of EGFR with PLK1 Exerts Therapeutic Synergism in Taxane-Resistant Lung Adenocarcinoma by Suppressing ABC Transporters.

To overcome the limitations of chemoresistance, combination therapies using druggable targets have been investigated. Our previous studies led us to hypothesize that the downregulation of PLK1 expression or activity can be one strategy to overcome the hurdles of taxane resistance by the downregulation of ABC transporters. To explore this, various versions of PLK1 including a constitutively active version, kinase-dead form, and polo-box domain mutant were expressed in paclitaxel-resistant lung adenocarcinoma (LUADTXR). Targeting PLK1 using shRNA or non-functional mutants downregulated ABCB1, ABCC9, and ABCG2 in LUADTXR cells, which was similar to the downregulation effects from treatment with PLK1 inhibitors. The high expression of EGFR in LUAD led us to administer gefitinib, showing a markedly reduced EGFR level in LUADTXR cells. When gefitinib and PLK1 inhibitors were combined, LUADTXR cells tended to undergo apoptosis more effectively than parental cells, showing a synergistic effect on the downregulation of ABC transporters through c-Myc and AP-1. Clinical data provide evidence for the relevance between survival rates and expressions of PLK1 and EGFR in LUAD patients. Based on these results, we suggest that a combination of gefitinib and PLK1 inhibitors exerts strong synergism in LUADTXR, which helps to overcome the limitations associated with taxanes.