Targeting CXCR4 and FAK reverses doxorubicin resistance and suppresses invasion in non-small cell lung carcinoma

Background

Current high lung cancer mortality rates are mainly due to the occurrence of metastases and therapeutic resistance. Therefore, simultaneous targeting of these processes may be a valid approach for the treatment of this type of cancer. Here, we assessed relationships between CXC chemokine receptor type 4 (CXCR4) and focal adhesion kinase (FAK) gene expression levels and expression levels of the drug resistance-related genes ABCB1 and ABCC1, and tested the potential of CXCR4 and FAK inhibitors to reverse doxorubicin (DOX) resistance and to decrease the invasive capacity of non-small cell lung carcinoma (NSCLC) cells.

Methods

qRT-PCR was used for gene expression analyses in primary lung tissue samples obtained from 30 NSCLC patients and the human NSCLC-derived cell lines NCI-H460, NCI-H460/R and COR-L23. MTT, flow cytometry, cell death and β-galactosidase activity assays were used to assess the in vitro impact of CXCR4 and FAK inhibitors on DOX sensitivity. In addition, invasion and gelatin degradation assays were used to assess the in vitro impact of the respective inhibitors on metastasis-related processes in combination with DOX treatment.

Results

We found that ABCB1 over-expression was significantly associated with CXCR4 and FAK over-expression, whereas ABCC1 over-expression was associated with increased FAK expression. We also found that CXCR4 and FAK inhibitors strongly synergized with DOX in reducing cell viability, arresting the cell cycle in the S or G₂/M phases and inducing senescence. Additionally, we found that DOX enhanced the anti-invasive potential of CXCR4 and FAK inhibitors by reducing gelatin degradation and invasion.

Conclusions

From our data we conclude that targeting of CXCR4 and FAK may overcome ABCB1 and ABCC1-dependent DOX resistance in NSCLC cells and that simultaneous treatment of these cells with DOX may potentiate the anti-invasive effects of CXCR4 and FAK inhibitors.

     

Knockdown of OCT4 may sensitize NSCLC cells to cisplatin

Purpose

Cisplatin is commonly used in non-small-cell lung cancer (NSCLC) chemotherapy; however, chemoresistance to cisplatin remains a great clinical challenge. Octamer-binding protein 4 (OCT4) has been reported to be overexpressed in NSCLC. In this study, we aimed to investigate the potential role of OCT4 in NSCLC with chemoresistance to cisplatin.

Methods

Expressions of OCT4 was detected in NSCLC tissues and cell lines. We utilized siRNA to knock down OCT4 expression in human NSCLC cells and analyzed their phenotypic changes.

Results

We found that the difference of OCT4 expression between NSCLC and the adjacent non-tumourous tissues was statistically significant. Knockdown of OCT4 in NSCLC cells could decrease cell proliferation, and potentiate apoptosis induced by cisplatin, suggesting OCT4 may contribute to cisplatin resistance in NSCLC.

Conclusion

Our findings indicate that targeting OCT4 could improve cisplatin effect in NSCLC, confirming their role in modulating cisplatin sensitivity.

     

Discovery of a Potent and Mutant-Selective EGFR Inhibitor that Overcomes T790M-Mediated Resistance in Lung Cancer

Background

Despite remarkable activity in epidermal growth factor receptor (EGFR)-mutant lung cancer patients, the clinical efficacy of EGFR tyrosine kinase inhibitors (TKIs) is limited by the emergence of acquired resistance, which is mostly caused by a secondary T790M mutation. Fortunately, newly developed, mutant-selective EGFR-TKIs against T790M have been proven as an effective therapeutic approach although only osimertinib has received the FDA approval until now.

Objective

To determine the in vitro and in vivo efficacy of a new EGFR TKI, OBX1-012 in cells with mutant EGFR.

Methods

Effects of OBX1-012 on cellular viability and EGFR-related signaling were determined in EGFR-mutant non-small cell lung cancer (NSCLC) cells, including cells harboring T790M mutations. In addition, in vivo efficacy of OBX1-012 was evaluated in xenograft models.

Results

We report the discovery and preclinical assessment of another novel, mutant-selective EGFR-TKI, OBX1-012. Compared with other mutant-selective EGFR-TKIs such as olumitinib and osimertinib, it showed similar potency and selectivity for mutant EGFR. OBX1-012 treatment was highly effective against human EGFR-mutant lung cancer models with or without EGFR T790M, not only in vitro but also in vivo. However, OBX1-012 like other EGFR-TKIs failed to exhibit efficacy for the exon 20 insertion mutation or C797S mutation, which was generated by site-directed mutagenesis and stable transfection of Ba/F3 cells.

Conclusions

These results identify OBX1-012 as a highly effective, mutant-selective EGFR-TKI for the treatment of T790M-mediated resistance in NSCLC.

     

miR-1268a regulates ABCC1 expression to mediate temozolomide resistance in glioblastoma

Introduction

Temozolomide (TMZ) is the preferred chemotherapeutic drug approved for the Glioblastoma multiforme (GBM) treatment. However, resistance to TMZ is the most intractable challenge for treatment of GBM. Screening of miRNAs is becoming a novel strategy to reveal underlying mechanism of drug-resistance of human tumors.

Materials and methods

We conducted RNA sequencing (RNA-seq) for GBM cells treated continuously with TMZ 1 or 2 week or not. Bioinformatic analysis was used to predict targets of these altered miRNAs. Subsequently, we studied the potential role of miR-1268a in TMZ-resistance of GBM cells.

Results

Expression levels of 55 miRNAs were identified altering both after 1 and 2 weeks TMZ treatment. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to illuminate the biological implication and related pathways of predicted target genes. We showed that miR-1268a was downregulated after TMZ treatment and targeted ABCC1/MRP1, a membrane transporter contributing to drug resistance, using dual-luciferase assay. Furthermore, we confirmed overexpression of miR-1268a inhibited protein translation of ABCC1 and restored upregulated expression of ABCC1 due to TMZ. Inversely, knockdown of miR-1268a increased ABCC1 at protein level and enhanced upregulation of ABCC1 with TMZ treatment. In addition, our data indicated that miR-1268a enhanced TMZ sensitivity in GBM cells.

Conclusion

Through RNA-seq analysis, we discovered miR-1268a and elucidated its role in modulating TMZ-resistance of GBM cells by targeting ABCC1.

     

High expression of long non-coding RNA ATB indicates a poor prognosis and regulates cell proliferation and metastasis in non-small cell lung cancer

Background and aim

Long non-coding RNAs (lncRNAs) have been demonstrated to act as a critical regulator in the processes of tumor biology. In this study, whether lncRNA-ATB is a potential indicator for non-small cell lung cancer (NSCLC) was investigated and its biological function in NSCLC was also determined.

Methods

The expression levels of lncRNA-ATB in NSCLC tissues and cell lines were measured. A549 cell line was explored to investigate the functions of lncRNA-ATB in NSCLC.

Results

Real-time PCR results showed that lncRNA-ATB expression was up-regulated in both in NSCLC tissues and cell lines. High lncRNA-ATB expression in tumor tissue was associated with larger tumor size, lymph node metastasis, and distant metastasis in patients with NSCLC, respectively. In addition, the patients with high expression of lncRNA-ATB presented a lower survival probability. In vitro experiments showed that down-regulation of lncRNA-ATB promoted the cell apoptosis, whereas inhibited the cell viability, cell migration, and cell invasion.

Conclusion

High expression of lncRNA-ATB indicated a poor prognosis and led to the cell proliferation and metastasis in NSCLC.

     

MicroRNA-585 acts as a tumor suppressor in non-small-cell lung cancer by targeting <Emphasis Type="Italic">hSMG</Emphasis>-<Emphasis Type="Italic">1</Emphasis>

Purpose

To investigate the role of miR-585 in the development and progression of non-small-cell lung cancer (NSCLC).

Methods

The expression levels of miR-585 in NSCLC cell lines and clinical samples were measured by quantitative PCR. NSCLC cells, A549 and H1299, were stably transfected with lentiviral vectors of miR-585 mimics or negative control. The effects of miR-585 on cell proliferation were detected both in vitro and in vivo. Cell migration and invasion were evaluated using wound healing assay and Transwell assay. Furthermore, luciferase reporter assay was used to identify the direct regulation of hSMG-1 by miR-585.

Results

Our results showed that miR-585 was downregulated in NSCLC cell lines and tumor tissues. Ectopic expression of miR-585 inhibited the ability of cell proliferation, migration, and invasion in vitro. In addition, miR-585 also decreased the growth rate of xenografted tumor in nude mice. Mechanically, miR-585 directly targeted the 3′-untranslated region (UTR) of hSMG-1 gene, which likely resulted in a dysfunction of mRNA surveillance and nonsense-mediated mRNA decay.

Conclusion

Taken together, miR-585 probably has an inhibitory effect on tumor growth and is a prognostic biomarker of NSCLC.

     

The functional status of DNA repair pathways determines the sensitization effect to cisplatin in non-small cell lung cancer cells

Purpose

Cisplatin can cause a variety of DNA crosslink lesions including intra-strand and inter-strand crosslinks (ICLs), which are associated with the sensitivity of cancer cells to cisplatin. Here, we aimed to assess the contribution of the Fanconi anemia (FA), homologous recombination (HR) and nucleotide excision repair (NER) pathways to cisplatin resistance in non-small cell lung cancer (NSCLC)-derived cells.

Methods

The expression of FA, HR and NER pathway-associated genes was assessed by RT-qPCR and Western blotting. siRNAs were used to knock down the expression of these genes. CCK-8 and flow cytometry assays were used to assess the viability and apoptotic rate of NSCLC-derived cells, respectively. Immunofluorescence and alkaline comet assays were used to assess the repair of ICLs.

Results

We found that acquired cisplatin-resistant NSCLC-derived A549/DR cells exhibited markedly enhanced FA and HR repair pathway capacities compared to its parental A549 cells and another independent NSCLC-derived cell line, Calu-1, which possesses a moderate innate resistance to cisplatin. siRNA-mediated silencing of the FA-associated genes FANCL and RAD18 and the HR-associated genes BRCA1 and BRCA2 significantly potentiated the sensitivity of A549/DR cells to cisplatin compared to A549 and Calu-1 cells, suggesting that the acquired cisplatin resistance in A549/DR cells may be attributed to enhanced FA and HR pathway capacities responsible for ICL repair. Although we found that expression knockdown of the NER-associated genes XPA and ERCC1 sensitized the three NSCLC-derived cell lines to cisplatin, the sensitization effect was more significant in Calu-1 cells than in A549 and A549/DR cells, implying that the innate cisplatin resistance in Calu-1 cells may result from an increased NER activity.

Conclusions

Our results indicate that the functional status of DNA repair pathways determine the sensitivity of NSCLC cells to cisplatin. Direct targeting of the pathway that is involved in cisplatin resistance may be an effective strategy to surmount cisplatin resistance in NSCLC.

     

SIRT6 drives epithelial-to-mesenchymal transition and metastasis in non-small cell lung cancer via snail-dependent transrepression of KLF4

Background

Epithelial-to-mesenchymal transition (EMT) contributes to the invasion and metastasis of epithelial tumors. Sirtuin 6 (SIRT6), an NAD-dependent deacetylase, is known to promote metastasis of non-small cell lung cancer (NSCLC).

Methods

In this work, we determined the role of SIRT6 in the EMT of NSCLC cells and identified the key EMT-related genes involved in the oncogenic activity of SIRT6.

Results

We report that depletion of SIRT6 inhibits transforming growth factor-β1 (TGF-β1)-induced EMT in A549 and H1299 NSCLC cells, which is rescued by ectopic expression of SIRT6. Knockdown of SIRT6 leads to a reduction in Snail protein without affecting the mRNA level. Immunoprecipitation experiments demonstrate a physical association between SIRT6 and Snail. SIRT6 deacetylates Snail and prevents its proteasomal degradation. Silencing of Snail blunts SIRT6-induced NSCLC cell migration and invasion, while overexpression of Snail restores the invasion and EMT in SIRT6-depleted NSCLC cells. SIRT6 depletion leads to an upregulation of kruppel-like factor 4 (KLF4) and reduced Snail binding to the promoter of Klf4 in NSCLC cells. Knockdown of KLF4 rescues the invasive capacity in SIRT6-depleted NSCLC cells. Conversely, co-expression of KLF4 impairs SIRT6-induced aggressive behavior. In vivo data further demonstrate that SIRT6-induced NSCLC metastasis is antagonized by overexpression of KLF4.

Conclusions

These findings provide mechanistic insights into the pro-metastatic activity of SIRT6 and highlight the role of the SIRT6/Snail/KLF4 axis in regulating EMT and invasion of NSCLC cells.

     

Prognostic value of glucosylceramide synthase and P-glycoprotein expression in oral cavity cancer

Background

Glucosylceramide synthase (GCS) and P-glycoprotein (P-gp) overexpression are associated with multidrug resistance in several human cancers. This study investigated the prognostic value of GCS and P-gp in oral cavity squamous cell carcinoma (OSCC).

Methods

The association between GCS and P-gp overexpression and clinical outcomes was assessed in 186 human clinical specimens of primary tumors obtained from curative surgery. Immunohistochemistry staining results were scored as high or low for GCS, and positive or negative for P-gp. Univariate and multivariate analyses using the Cox proportional hazards model were conducted to assess the significance of differences in recurrence or survival outcomes between variables.

Results

GCS overexpression was observed in 128 (68.8 %) patients and P-gp overexpression in 43 (23.1 %) patients. High GCS expression was significantly correlated with P-gp immunopositivity (P = 0.005). GCS and P-gp overexpression was significantly correlated with cervical nodal metastasis (P < 0.05). Univariate analyses showed that tumor lymphovascular invasion, positive neck lymph nodes, advanced overall TNM stage, high GCS expression, and P-gp immunopositivity were associated with poor locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) (P < 0.05). Multivariate analyses showed that lymphovascular invasion, nodal positivity, and P-gp overexpression remained independent prognostic variables for LRC, DFS, and OS, and that GCS expression was an independent predictor of LRC and DFS (P < 0.05).

Conclusion

GCS and P-gp expression is associated with poor prognosis, suggesting suitability as novel biomarkers in OSCC.

     

The role of PRMT1 in EGFR methylation and signaling in MDA-MB-468 triple-negative breast cancer cells

Background

Epidermal growth factor receptor (EGFR) is often overexpressed in triple-negative breast cancer (TNBC). However, clinical studies have shown that therapies against EGFR are not effective in patients with TNBC. Recently, it has been reported that arginine 198/200 in EGFR extracellular domain is methylated by PRMT1 and that the methylation confers resistance to EGFR monoclonal antibody cetuximab in colorectal cancer cells. To explore a potential mechanism underlying intrinsic resistance to anti-EGFR therapy in TNBC, we investigated the role of PRMT1 in EGFR methylation and signaling in MDA-MB-468 (468) TNBC cells.

Methods

We knocked down PRMT1 in 468 cells by shRNA, and subjected the cell lysates to Western blot analysis to examine EGFR activation and its downstream molecules. We also evaluated cell proliferation and sphere formation of PRMT1-knockdown cells. Finally, we examined the effects of pan-PRMT inhibitor, AMI-1, on cetuximab by colony formation and soft agar assays.

Results

EGFR methylation and activity was significantly reduced in PRMT1-knockdown cells compared to the parental cells. Knockdown of PRMT1 also reduced cell proliferation and sphere formation. Moreover, AMI-1 sensitized 468 cells to cetuximab.

Conclusion

The results indicate that PRMT1 is critical for EGFR activity in 468 cells. Our data also suggest that inhibition of PRMT1 sensitizes TNBC cells to cetuximab. Thus, inhibition of PRMT1 may be an effective therapeutic strategy to overcome intrinsic resistance to cetuximab in TNBC.

     

MDMX is a prognostic factor for non-small cell lung cancer and regulates its sensitivity to cisplatin

Purpose

Chemoradiotherapy is the standard treatment modality for advanced non-small cell lung cancer (NSCLC). However, drug and radiation resistance remain major factors influencing its clinical outcome. The purpose of this study was to evaluate whether MDMX can affect the chemosensitivity and clinical outcome of NSCLC.

Methods

Quantitative real-time PCR (qRT-PCR) was performed to assess MDMX mRNA expression levels in 105 primary NSCLC tissues, its corresponding non-cancerous tissues and two NSCLC-derived cell lines (A549 and SK-MES-1). In addition, immunohistochemistry was carried out to detect MDMX protein expression in the primary NSCLC tissues. The MDMX expression levels were correlated with clinicopathological and survival features. The effects of MDMX expression knockdown on NSCLC cell proliferation and chemosensitivity were evaluated using MTT, flow cytometry and soft agar colony assays.

Results

We found that the mRNA expression level of MDMX in NSCLC tissues was significantly higher than that in its corresponding non-tumorous tissues. High MDMX expression was found to be related to poor tumor cell differentiation, advanced TNM stages and the occurrence of lymph node metastases. Patients with a high MDMX expression level exhibited a lower overall survival rate than those with a low expression level. Multivariate analysis showed that a high MDMX protein expression level may serve as an independent prognostic factor for NSCLC patients. In addition, we found that MDMX expression knockdown combined with cisplatin treatment in vitro significantly increased apoptosis and decreased soft agar colony formation in NSCLC-derived cells.

Conclusions

Our data indicate that MDMX expression may serve as an independent unfavorable prognostic factor for NSCLC patient outcome, which in turn may at least partly be due to the ability of the MDMX protein to regulate the proliferative capacity and chemosensitivity of NSCLC cells.

     

Nichtkleinzelliges Lungenkarzinom – Pathologie und Biologie

Background

Non-small cell lung cancer (NSCLC) accounts for ca. 75% of malignant epithelial neoplasms of the lungs. In recent years profound insight has been gained regarding the molecular mechanisms of lung carcinogenesis and subsequently new targeted therapies as well as immunotherapies have been developed. These advances have had a significant impact on routine diagnostics in pathology.

Objective

The article aims to give an overview of the most common histological subtypes of NSCLC as well as the morphological, immunohistochemical and molecular characteristics.

Material and methods

Selective search of the PubMed database.

Results and discussion

Adenocarcinomas, squamous cell carcinomas and large cell carcinomas are the most common histological subtypes. With the ancillary methods available in routine pathology even poorly differentiated tumors can be assigned to these entities. The NSCLC show numerous genetic changes of which alterations of EGFR, MET, ALK1 and ROS1 are target structures for personalized therapy.

     

Efficacy of doxorubicin-transferrin conjugate in apoptosis induction in human leukemia cells through reactive oxygen species generation

Background

Doxorubicin (DOX) is a small molecular cytotoxic agent that can be transferred efficiently to cancer cells by nanocarriers. This anthracycline antibiotic serves as an effective anti-neoplastic drug against both hematological and solid malignancies. Here, we set out to assess the capacity of a novel doxorubicin - transferrin conjugate (DOX-TRF) to provoke apoptosis in human normal and leukemia cells through free radicals produced via a redox cycle of doxorubicin (DOX) when released from its conjugate.

Methods

After DOX-TRF exposure, we determined the time-course of apoptotic and necrotic events, the generation of reactive oxygen species (ROS), changes in mitochondrial membrane potential, as well as alterations in cytochrome c levels and intracellular calcium concentrations in human leukemia-derived cell lines (CCRF-CEM, K562 and its doxorubicin-resistant derivative K562/DOX) and normal peripheral blood-derived mononuclear cells (PBMC).

Results

We found that DOX-TRF can induce apoptosis in all leukemia-derived cell lines tested, which was associated with morphological changes and decreases in mitochondrial membrane potential. In comparison to free DOX treated cells, we observed a time-dependency between a higher level of ROS generation and a higher drop in mitochondrial membrane potential, particularly in the doxorubicin-resistant cell line. In addition, we found that the apoptotic cell death induced by DOX-TRF was directly associated with a release of cytochrome c from the mitochondria and an increase in intracellular calcium level in all human leukemia-derived cell lines tested.

Conclusions

Our data indicate that DOX-TRF is considerably more cytotoxic to human leukemia cells than free DOX. In addition, we show that DOX-TRF can effectively produce free radicals, which are directly involved in apoptosis induction.

     

Prognostic value of <Emphasis Type="Italic">ERCC1, RRM1, BRCA1</Emphasis> and <Emphasis Type="Italic">SETDB1</Emphasis> in early stage of non-small cell lung cancer

Introduction

Nowadays, 40 % of early-stage NSCLC patients relapse in the 2 years following resection, suggesting a mis-staging in this group of patients who are not receiving adjuvant chemotherapy. Although different biomarkers, such as ERCC1, RRM1 and BRCA1 have been found to present prognostic value in advanced NSCLC patients, in early-stage NSCLC patients its relevance remains unclear. Moreover, SETDB1 has been recently proposed as a bona fide oncogene in lung tumourigenesis and related with metastasis. The aim of the present study was to analyze the prognostic value of ERCC1, RRM1, BRCA1 and SETDB1 expression levels in NSCLC patients at stage I.

Patients and methods

ERCC1, RRM1, BRCA1 and SETDB1 expression at mRNA level was analyzed by real-time quantitative RT-PCR in fresh-frozen tumor and normal adjacent lung tissue samples from 64 stage I NSCLC patients. Later, significant association between gene expression levels, clinicopathological characteristics and patient’s disease-free survival was assessed.

Results

We did not find any statistically significant correlation between gene expression and gender, age, histological type or smoking status. Univariate followed by multivariate Cox analysis showed that higher levels of BRCA1 and SETDB1 expression were significantly associated with shorter disease-free survival in stage I NSCLC patients.

Conclusion

Our study finds that ERCC1 and RRM1 are not independent prognostic factors of recurrence in stage I NSCLC patients. By contrast, BRCA1 and SETDB1 stand out as the most significant prognostic markers in this group of patients, appearing as promising tools to predict tumor recurrence in early-stage NSCLC patients.

     

Palliative Care in Lung Cancer: When to Start

Purpose of Review

Despite recent advances in the care of patients with advanced non-small cell lung cancer (NSCLC), significant morbidity and mortality remains. Symptoms caused by the cancer and its treatments can be profoundly debilitating. Palliative care aims to reduce this burden. In this review, we discuss the definition, purpose, benefits, and optimal timing of palliative care in advanced NSCLC.

Recent Findings

Several studies evaluating the value of early palliative care for patients with advanced NSCLC and other advanced malignancies have identified benefits for patients, caregivers, and health systems.

Summary

For patients with advanced NSCLC, introduction of palliative care early in the disease course improves quality of life and even overall survival. Early institution of palliative care should become standard of care for patients with advanced NSCLC.

     

Changes in programmed death ligand 1 expression in non-small cell lung cancer patients who received anticancer treatments

Background

The expression of programmed death ligand 1 (PD-L1) is considered a predictive biomarker of anti-programmed death 1 (PD-1)/PD-L1 cancer therapies. However, changes in PD-L1 expression of tumor cells during clinical courses have not been fully evaluated. We evaluated changes in PD-L1 expression for non-small cell lung cancer (NSCLC) patients who received anticancer treatments during clinical courses.

Methods

In 76 NSCLC patients, PD-L1 expression was evaluated before and after anticancer treatment by immunohistochemical (IHC) analysis using an anti-PD-L1 antibody. We defined two cut-off points of PD-L1 expression (1 and 50%) and three corresponding IHC groups (A: 0%, B: 1–49%, and C: ≥50%). IHC group B and C were considered to be positive expression, and we defined the difference of IHC group between pre- and post-treatment as ‘major change’ in PD-L1 expression.

Results

Before anticancer treatment, PD-L1 expression was observed in 38/76 (50%) patients, and was significantly less common in patients harboring mutations in the epidermal growth factor receptor gene (EGFR) than in those without (P?=?0.039). After anticancer treatment, PD-L1 expression was observed in 36/76 (47%) patients. Major increases in PD-L1 expression were seen in 11 (14%), and major decreases in 18 (24%) patients. Among 13 patients harboring EGFR mutations treated with EGFR tyrosine-kinase inhibitor (EGFR-TKI), five (38%) showed major increases.

Conclusion

Major changes of PD-L1 expression in tumor cells were observed in 38% of NSCLC patients who received anticancer treatments. And, treatments with EGFR-TKI may increase PD-L1 expression in NSCLC patients harboring EGFR mutations.

     

Stromal markers AKR1C1 and AKR1C2 are prognostic factors in primary human breast cancer

Background

Stromal fibroblasts influence tumor growth and progression. We evaluated two aldo–keto reductases, AKR1C1 and AKR1C2, in stromal fibroblasts and carcinoma cells as prognostic factors in primary human breast cancer. They are involved in intratumoral progesterone metabolism.

Methods

Immunohistochemistry was performed on tissue microarrays from 504 core biopsies from breast cancer patients. Primary endpoints were disease-free (DFS) and overall (OS) survival.

Results

AKR1C1 and AKR1C2 expression in fibroblasts and tumor cells correlated with favorable tumor characteristics, such as small tumor size and negative nodal status. In univariate analysis, AKR1C1 expression in carcinoma cells correlated positively with DFS und OS; AKR1C2 expression in both fibroblasts and tumor cells also showed a positive correlation with DFS and OS. In multivariate analysis, AKR1C1 expression in carcinoma cells was an independent prognostic marker.

Conclusion

It can be assumed that our observations are due to the independent regulatory function of AKR1C1/2 in progesterone metabolism and therefore provide a basis for new hormone-based therapy options for breast cancer patients, independent of classic hormone receptor status.

     

CEACAM1 and hollow spheroid formation modulate the chemosensitivity of colorectal cancer to 5-fluorouracil

Purpose

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) re-expressed and promoted hollow spheroid (HS) formation beyond the invasion front of colorectal cancer. The aim of the present study was to clarify whether CEACAM1 cytoplasmic domain isoform balance and HS are associated with resistance to 5-fluorouracil (5FU).

Methods

Two-dimensional (D) or 3D culture systems were employed to evaluate the effects of CEACAM1 cytoplasmic isoform balance and HS formation on the chemosensitivity of colorectal cancer cells to 5FU. The risk factors for postoperative recurrence were calculated based on the presence of HS and various clinicopathological characteristics in 82 patients with Stage III colorectal cancer who had undergone curative surgery followed by 5FU-based chemotherapy.

Results

CEACAM1-4L-transfected HT29 and CEACAM1-4L and 4S expressing parental LS174T cells had significantly higher resistance to 5FU in comparison with CEACAM1-4S- or vector control-transfected cells. In 3D culture, HS formation induced by CEACAM1-4L induced chemoresistance to 5FU, whereas the solid spheres formed in response to CEACAM1-4S were destroyed by 5FU treatment. HS was identified as an independent factor for recurrence of Stage III colorectal cancer after curative resection followed by 5FU-based chemotherapy. Kaplan–Meier survival curves demonstrated that patients with HS had lower recurrence-free survival rate.

Conclusions

CEACAM1 long cytoplasmic domain isoform dominance and HS formation are phenotypes associated with chemoresistance to 5FU.