Cell-cycle regulators and the Ki-67 labeling index can predict the response to chemoradiotherapy and the survival of patients with locally advanced squamous cell carcinoma of the esophagus

Exploiting the Molecular Basis of Oesophageal Cancer for Targeted Therapies and Biomarkers for Drug Response: Guiding Clinical Decision-Making

Worldwide, oesophageal cancer is the sixth leading cause of deaths related to cancer and represents a major health concern. Sub-Saharan Africa is one of the regions of the world with the highest incidence and mortality rates for oesophageal cancer and most of the cases of oesophageal cancer in this region are oesophageal squamous cell carcinoma (OSCC). The development and progression of OSCC is characterized by genomic changes which can be utilized as diagnostic or prognostic markers. These include changes in the expression of various genes involved in signaling pathways that regulate pathways that regulate processes that are related to the hallmarks of cancer, changes in the tumor mutational burden, changes in alternate splicing and changes in the expression of non-coding RNAs such as miRNA. These genomic changes give rise to characteristic profiles of altered proteins, transcriptomes, spliceosomes and genomes which can be used in clinical applications to monitor specific disease related parameters. Some of these profiles are characteristic of more aggressive forms of cancer or are indicative of treatment resistance or tumors that will be difficult to treat or require more specialized specific treatments. In Sub-Saharan region of Africa there is a high incidence of viral infections such as HPV and HIV, which are both risk factors for OSCC. The genomic changes that occur due to these infections can serve as diagnostic markers for OSCC related to viral infection. Clinically this is an important distinction as it influences treatment as well as disease progression and treatment monitoring practices. This underlines the importance of the characterization of the molecular landscape of OSCC in order to provide the best treatment, care, diagnosis and screening options for the management of OSCC.

miR-30a attenuates drug sensitivity to 5-FU by modulating cell proliferation possibly by downregulating cyclin E2 in oral squamous cell carcinoma

We aimed to determine the functional role of the miRNA, which affects drug sensitivity to 5-FU in oral squamous cell carcinoma (OSCC), using two types of 5-FU-resistant and parental OSCC cell lines. MiRNA microarray data showed that miR-30a was significantly upregulated in two resistant cell lines. Therefore, we investigated the effects and molecular mechanism of miR-30a on 5-FU sensitivity. Stable overexpression of miR-30a in parental OSCC cells decreased cell proliferation and attenuated drug sensitivity to 5-FU. Cell cycle analysis indicated that miR-30a overexpression increased the proportion of G1 phase cells and decreased the proportion of S phase cells. MiR-30a knockdown using siRNA reversed the effects of miR-30a overexpression. DNA microarray analysis using miR-30a-overexpressing cell lines and a TargetScan database search showed that cyclin E2 (CCNE2) is a target of miR-30a. A luciferase reporter assay confirmed that a miR-30a mimic interacted with the specific binding site in the 3' UTR of CCNE2. CCNE2 knockdown with siRNA in OSCC cells yielded decreased drug sensitivity to 5-FU, similar to miR-30a overexpressing cells. These findings suggest that miR-30a in OSCC may be a novel biomarker of 5-FU-resistant tumors, as well as a therapeutic target for combating resistance.

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miR-30a overexpression increased the proportion of G1 phase cells.

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miR-30a knockdown using si-RNA reversed the effects of miR-30a overexpression.

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CCNE2 knockdown with si-RNA in OSCC cells decreased drug sensitivity to 5-FU.

Prognostic features of the tumour microenvironment in oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is a disease with an incredibly poor survival rate and a complex makeup. The growth and spread of OAC tumours are profoundly influenced by their surrounding microenvironment and the properties of the tumour itself. Constant crosstalk between the tumour and its microenvironment is key to the survival of the tumour and ultimately the death of the patient. The tumour microenvironment (TME) is composed of a complex milieu of cell types including cancer associated fibroblasts (CAFs) which make up the tumour stroma, endothelial cells which line blood and lymphatic vessels and infiltrating immune cell populations. These various cell types and the tumour constantly communicate through environmental cues including fluctuations in pH, hypoxia and the release of mitogens such as cytokines, chemokines and growth factors, many of which help promote malignant progression. Eventually clusters of tumour cells such as tumour buds break away and spread through the lymphatic system to nearby lymph nodes or enter the circulation forming secondary metastasis. Collectively, these factors need to be considered when assessing and treating patients clinically. This review aims to summarise the ways in which these various factors are currently assessed and how they relate to patient treatment and outcome at an individual level.

Histopathologic findings in malignant peripheral nerve sheath tumor predict response to radiotherapy and overall survival

Background

Malignant peripheral nerve sheath tumor (MPNST) is an aggressive and poorly understood malignant neoplasm. Even in the setting of multimodal therapy, the clinical course of MPNST is frequently marked by metastatic conversion and poor overall prognosis, with optimal treatment paradigms for this rare tumor unknown.

Methods

We reviewed the medical records and histopathology of 54 consecutive patients who were treated at University of California San Francisco between 1990 and 2018.

Results

Our cohort consisted of 24 male and 30 female patients (median age 38 years). Fédération Nationale des Centres de Lutte Contre Le Cancer (FNCLCC) sarcoma grading criteria segregated patients into groups with differences in overall survival (OS) (P = .02). Increasing Ki-67 labeling index was associated with poor OS (hazard ratio [HR] 1.36 per 10%, P = .0002). Unsupervised hierarchical clustering-based immunohistochemical staining patterns identified 2 subgroups of tumors with differences in H3K27me3, Neurofibromin, S100, SOX10, p16, and EGFR immunoreactivity. In our cohort, cluster status was associated with improved locoregional failure-free rate (P = .004) in response to radiation.

Conclusions

Our results lend support to the FNCLCC sarcoma grading criteria as a prognostic scheme for MPNST, although few cases of grade 1 were included. Further, we identify increased Ki-67 labeling as a strong predictor of poor OS from MPNST. Finally, we identify a subset of MPNSTs with a predictive immunohistochemical profile that has improved local control with adjuvant radiotherapy. These data provide insights into the grading and therapy for patients with MPNST, although further studies are needed for independent validation.

Loss of p16 and high Ki67 labeling index is associated with poor outcome in esophageal carcinoma

The p16 tumor suppressor is coded by CDKN2A (9p21) and plays an important role during carcinogenesis and tumor progression in numerous tumor entities. The aim of our study was to evaluate the prognostic role of p16 expression and CDKN2A deletion in esophageal cancer (EC). Therefore, we analyzed p16 and KI67 expression by immunohistochemistry and 9p21 deletion by fluorescence in-situ hybridization on a tissue microarray including 398 adenocarcinomas (AC) and 293 squamous cell carcinomas (SCC) with clinical follow up-data. p16 positivity was found in 30.2% of AC and 13.9% of SCC and CDKN2A deletion in 32.1% of AC and 33.5% of SCC. In SCC p16 immunostaining correlated with low tumor stage (P = 0.014). In AC Ki67 positivity was associated with high tumor stage (P = 0.001), presence of lymph node metastasis (P = 0.009), high UICC stage (P = 0.001) and poor grading (P = 0.005). Overall survival (OS) was shorter for patients with high Ki67 labeling index (Ki67LI; P = 0.009) and negative p16 immunostaining (P = 0.026). In both histological tumor types, CDKN2A deletion showed no association with phenotype or outcome. Proportional cox-regression modeling revealed patients' age, tumor stage, lymph node metastasis and Ki67 labeling index as independent prognostic markers in AC. In SCC, only patients' age and tumor stage proved to be independent prognosticators. In summary, our study shows that loss of p16 expression and high Ki67LI is linked to shortened OS in AC. CDKN2A deletion shows no relevant association with tumor phenotype and patient outcome.

Postoperative Pneumonia is Associated with Long-Term Oncologic Outcomes of Definitive Chemoradiotherapy Followed by Salvage Esophagectomy for Esophageal Cancer

BACKGROUND OR PURPOSE

As we previously indicated, postoperative pneumonia has a negative impact on the overall survival after planned esophagectomy. However, the impact of postoperative pneumonia after salvage esophagectomy on long-term oncologic outcomes still remains unclear. This study aimed to indicate the association between postoperative pneumonia and long-term outcomes of definitive chemoradiotherapy followed by salvage esophagectomy. Furthermore, we determined a prediction model for overall survival (OS) and disease-free survival (DFS) using a survival classification and regression tree (CART).

METHODS

Ninety-three patients who underwent CRT followed by esophagectomy for thoracic esophageal cancer were identified for this study. Forty-nine patients and 44 patients were included in the salvage and neoadjuvant groups, respectively. We investigated the association between postoperative pneumonia and long-term oncologic outcomes following salvage esophagectomy.

RESULTS

Patients from the salvage group tended to have a lower OS compared to neoadjuvant group (median survival: salvage, 24 months vs neoadjuvant, 43 months, p = 0.117). Multivariate analyses revealed that postoperative pneumonia adversely affected both OS (p < 0.001) and DFS (p = 0.044) after salvage esophagectomy. We generated the prediction model for OS and DFS in the salvage group using survival CART. Postoperative pneumonia was the most important parameter for predicting the OS.

DISCUSSION

The present study demonstrates the long-term outcomes and risk factors for mortality of salvage esophagectomy. To improve OS after salvage surgery, the development of a means of decreasing pulmonary complications is needed.

MIB-1 index is unlikely to predict relapse-free survival in patients who underwent R0-esophagectomy for esophageal squamous cell carcinoma

MIB-1 is a cell proliferation marker and has previously been investigated as a diagnostic or prognostic indicator of malignancy. Previous studies have investigated MIB-1 index and clinicopathological factors in relation to prognosis of patients with esophageal cancer, with conflicting results. The aim of this study is to assess the prognostic significance of MIB-1 index in patients with thoracic esophageal squamous cell carcinoma. A total of 78 patients who underwent R0-esophagectomy for thoracic esophageal squamous cell carcinoma were enrolled in this study. Preoperatively, 29 patients underwent chemotherapy, six underwent chemoradiotherapy, and the remaining did not undergo any preoperative therapy. The MIB-1 labeling index was reported by counting 500 tumor cells in the hot spots of nuclear labeling. Correlations between MIB-1 index, clinicopathological factors, and relapse-free survival (RFS) were investigated. The mean MIB-1 index was 39.3 ± 21.0 (range: 0-91.3). There was no significant correlation between clinicopathological factors and MIB-1 index in the study patients, irrespective of whether they underwent preoperative therapy. Univariate analysis revealed no significant association between MIB-1 index and RFS. However, depth of tumor invasion, lymph node metastasis and stage, all showed a significant correlation to RFS. Multivariate analysis of RFS revealed that stage was the only significant factor. Conversely, MIB-1 index was not significantly related to RFS (p = 0.41). In conclusion, MIB-1 index is unlikely to be a significant prognostic indicator for esophageal cancer.

Predictive biomarkers for response of esophageal cancer to chemo(radio)therapy: A systematic review and meta-analysis

BACKGROUND

Esophageal cancer remains a major public health issue worldwide. In clinical practice, chemo(radio)therapy is an important approach to patients with esophageal cancer. Only the part of patients who respond to chemo(radio)therapy achieve better long-term outcome. In this case, predictive biomarkers for response of esophageal cancer patients treated with chemo(radio)therapy are of importance. Meta-analysis of P53 for predicting esophageal cancer response has been reported before and is not included in our study. We performed a systematic review and meta-analysis to summarize and evaluate the biomarkers for predicting response to chemo(radio)therapy.

METHOD

PubMed, Web of Science and the Ovid databases were searched to identify eligible studies published in English before March 2017. The risk ratio (or relative risk, RR) was retrieved in articles regarding biomarkers for predicting response of esophageal cancer patients treated with neoadjuvant therapy or chemo(radio)therapy. Fixed and random effects models were used to undertake the meta-analysis as appropriate.

RESULT

Forty-six articles reporting 56 biomarkers correlated with the response were finally included. Meta-analyses were carried out when there was more than one study related to the reported biomarker. Results indicated that low expression of (or IHC-negative) COX2, miR-200c, ERCC1 and TS was individually associated with prediction of response. The RR was 1.64 (n = 202, 95% CI 1.22-2.19, P < 0.001), 1.96 (n = 162, 95% CI 1.36-2.83, P < 0.001), 2.55 (n = 206, 95% CI 1.80-3.62, P < 0.001) and 1.69 (n = 144, 95% CI 1.10-2.61, P = 0.02), respectively. High expression of (or IHC-positive) CDC25B and p16 was individually related to prediction of response. The RR was 0.62 (n = 159, 95% CI 0.43-0.89, P = 0.01) and 0.62 (n = 142, 95% CI 0.43-0.91, P = 0.01), respectively.

CONCLUSION

Low expression of (or IHC-negative) COX2, miR-200c, ERCC1 and TS, or high expression of (or IHC-positive) CDC25B and p16 are potential biomarkers for predicting the response of esophageal cancer patients treated with chemo(radio)therapy.

Murine double minute 2 predicts response of advanced esophageal squamous cell carcinoma to definitive chemoradiotherapy

Background

Definitive chemoradiotherapy (dCRT) has recently become one of the most effective therapies for the treatment of esophageal squamous cell carcinoma (ESCC). However, it is also true this treatment has not been effective in all patients. Therefore, it is very important to evaluate the surrogate marker of dCRT in order to improve clinical outcomes of patients with ESCC. On the other hand, our previous study had suggested that murine double minute 2 (MDM2) and p16 were associated with chemoradioresistance in ESCC.

Methods

We selected pretreatment biopsy specimens of ESCC patients from our prospective clinical study on dCRT. Seventy-nine cases histologically diagnosed as ESCC were used. We immunohistochemically investigated these specimens using antibodies against MDM2, p53, p16, and Ki-67.

Results

The patients included 68 males and 11 females with a mean age of 63.3 years. The number of patients in each clinical stage was as follows: 22 in c-Stage I; 17 in c-Stage II; and 40 in c-Stage III. cT, cN, and cStage were significantly more advanced in the Failure group (including patients with persistent and recurrent disease after dCRT) than in the complete response (CR) group (patients with persistent CR after dCRT). The clinical stage inversely correlated with the CR rate and the rescue rate after failure. The overall survival rate was significantly worse in the patients with advanced cT, cN, and cStage levels, and in the Failure group. MDM2 positivity was significantly higher in the Failure group than in the CR group in cStageIII (P = 0.014). The number of patients with an absence of p16 immunoreactivity was significantly higher in the Failure group than in the CR group in cStageIII (P = 0.010) but not in cStageI or cStageII. Moreover, the overall survival with a Ki-67 ≥ 33.7% was significantly better than that with <33.7% for patients in cStageIII (P = 0.024).

Conclusions

The results of this study suggested that MDM2 and p16 are predictive markers for chemoradioresistance in cStageIII ESCC and Ki-67 is a prognostic marker following dCRT in cStageIII ESCC. These issues could contribute to the formulation of treatment strategy for patients with advanced ESCC.

CCND1/CyclinD1 status in metastasizing bladder cancer: a prognosticator and predictor of chemotherapeutic response

The CCND1 gene encodes the protein CyclinD1, which is an important promoter of the cell cycle and a prognostic and predictive factor in different cancers. CCND1 is amplified to a substantial proportion in various tumors, and this may contribute to CyclinD1 overexpression. In bladder cancer, information about the clinical relevance of CCND1/CyclinD1 alterations is limited. In the present study, amplification status of CCND1 and expression of CyclinD1 were evaluated by fluorescence in situ hybridization and immunohistochemistry on tissue microarrays from 152 lymph node-positive urothelial bladder cancers (one sample each from the center and invasion front of the primary tumors, two samples per corresponding lymph node metastasis) treated by cystectomy and lymphadenectomy. CCND1 amplification status and the percentage of immunostained cancer cells were correlated with histopathological tumor characteristics, cancer-specific survival and response to adjuvant chemotherapy. CCND1 amplification in primary tumors was homogeneous in 15% and heterogeneous in 6% (metastases: 22 and 2%). Median nuclear CyclinD1 expression in amplified samples was similar in all tumor compartments (60-70% immunostained tumor nuclei) and significantly higher than in non-amplified samples (5-20% immunostained tumor nuclei; P<0.05). CCND1 status and CyclinD1 expression were not associated with primary tumor stage or lymph node tumor burden. CCND1 amplification in primary tumors (P=0.001) and metastases (P=0.02) and high nuclear CyclinD1 in metastases (P=0.01) predicted early cancer-related death independently. Subgroup analyses showed that chemotherapy was particularly beneficial in patients with high nuclear CyclinD1 expression in the metastases, whereas expression in primary tumors and CCND1 status did not predict chemotherapeutic response. In conclusion, CCND1 amplification status and CyclinD1 expression are independent risk factors in metastasizing bladder cancer. High nuclear CyclinD1 expression in lymph node metastases predicts favorable response to chemotherapy. This information may help to personalize prognostication and administration of adjuvant chemotherapy.

Intervention effects of nedaplatin and cisplatin on proliferation and apoptosis of human tumour cells in vitro

OBJECTIVE

To study synergistic effects of nedaplatin and cisplatin on three human carcinoma cell lines (esophageal carcinoma cell line Eca-109, ovarian carcinoma Skov-3 and cervical carcinoma Hela).

METHODS

Inhibition effects were evaluated by MTT assay and cell apoptosis was detected by flow cytometry. In addition, changes of Ki-67, Bax and Bcl-2 at mRNA and protein levels were quantified by RT-PCR and Western blotting.

RESULTS

Growth inhibition in each cell lines was dose-dependent after exposure to nedaplatin or cisplatin alone. The interaction of the two drugs was synergistic at higher concentrations according to the median-effect principle. The inhibition rates with nedaplatin, cisplatin and combined treatment were 41.9±4.1%, 47.4±2.9%, 52.5±0.9%(Eca-109), 39.0±1.26%, 45.0±1.45% , 56.2±1.44% (Skov-3) and 44.8±2.11%, 46.9±0.99%, 56.6±1.83% (Hela) respectively, with increase in apoptosis. Compared with the nedaplatin or cisplatin alone treatment group, the combinative treatment group's Ki-67 and bcl-2 mRNA (protein) expression was decreased while that of Bax mRNA (protein) was increased.

CONCLUSION

Compared to the effects of nedaplatin or cisplatin alone at high concentrations, combination of nedaplatin and cisplatin at low concentrations proved to be much more effective for inhibition of proliferation and the induction of apoptosis in the Eca-109, Skov-3 and Hela cell lines.

Biomarkers for predicting the response of esophageal squamous cell carcinoma to neoadjuvant chemoradiation therapy. Surg Today. 2014;44:421-428. [PMID: 23605218 DOI: 10.1007/s00595-013-0580-y]

This review summarizes and evaluates the literature regarding the biomarkers for predicting the response and/or prognosis of esophageal squamous cell carcinoma (ESCC) patients treated with neoadjuvant chemoradiation therapy (CRT). There are seven categories of molecules known to correlate with the response and/or prognosis: tumor suppressors (p53, p21), cell cycle regulators (Cyclin D1, CDC25B, 14-3-3sigma), DNA repair molecules (p53R2, ERCC1), drug resistance proteins [metallothionein (MT)], angiogenic factors (VEGF), molecules involved in cell proliferation/invasion/metastasis (Ki-67, COX-2) and hedgehog signaling molecules (Gli-1). Of the above molecules, the tumor suppressor p53 is expected to be a representative biomarker for predicting the response and prognosis. The cell cycle markers CDC25B and 14-3-3sigma have potential as response biomarkers independent of the p53 status. The DNA repair markers, p53R2 or ERCC1, angiogenic molecule (VEGF), and hedgehog signaling pathway factor Gli-1 also have potential to predict the response and prognosis of ESCC. However, there are still many unanswered questions with regard to predicting the clinical effects of neoadjuvant CRT.

Correlation of p53 status with the response to chemotherapy-based treatment in esophageal cancer: a meta-analysis

BACKGROUND

The value of p53 status for predicting response to chemotherapy-based treatment in patients with esophageal cancer has been controversial. We conducted a meta-analysis to elucidate the correlation of p53 status with the response to chemotherapy-based treatment.

METHODS

Studies were searched in PubMed, Embase, and Web of Science (up to September 2012). The p53 status and response to therapy were defined and standardized. Subgroup analyses based on the treatment and histopathology were performed to explore the usefulness of p53 status for predicting response to therapy in esophageal cancer. Sensitivity analyses were conducted by removing specific studies to assess the effects of study quality.

RESULTS

We included 28 studies with 1497 cases in our meta-analysis. Wild-type form of p53 status (low expression of p53 protein and/or wild-type p53 gene) was associated with high response to chemotherapy-based treatment in esophageal cancer (total major response [MR]: risk ratio [RR] = 1.09, 95 % CI = 1.03-1.16, P = .003; pathological MR: RR = 1.15, 95 % CI = 1.06-1.25, P = .001; total complete response [CR]: RR = 1.08, 95 % CI = 1.00-1.17, P = .040). The similar correlation between the wild-type form p53 and response to therapy were also detected in subgroup analyses (total MR, pathological MR, and total CR in chemoradiotherapy subgroup; total MR in chemotherapy subgroup; total MR and pathological CR in esophageal squamous cell carcinoma [ESCC]). Additionally, patients with wild-type form p53 status had high pathological complete response rate to neoadjuvant chemoradiotherapy in ESCC.

CONCLUSIONS

The current meta-analysis suggested that p53 status might be a predictive biomarker for response to chemotherapy-based treatment in esophageal cancer.

Correlation among 16 biological factors [p53, p21(waf1), MIB-1 (Ki-67), p16(INK4A), cyclin D1, E-cadherin, Bcl-2, TNF-α, NF-κB, TGF-β, MMP-7, COX-2, EGFR, HER2/neu, ER, and HIF-1α] and clinical outcomes following curative chemoradiation therapy in 10 patients with esophageal squamous cell carcinoma

The expression levels of 16 proteins were analyzed to identify prognostic correlations in esophageal squamous cell carcinoma (ESCC) treated with concurrent chemoradiation therapy (CCRT). The immunohistochemical expression levels of p53, p21^waf1, molecular immunology borstel-1 (MIB-1, Ki-67), p16^INK4A, cyclin D1, E-cadherin, Bcl-2, tumor necrosis factor (TNF)-α, nuclear factor (NF)-κB, transforming growth factor (TGF)-β, matrix metalloproteinase (MMP)-7, cyclooxygenase (COX)-2, epidermal growth factor receptor (EGFR), human EGFR type 2 (HER2/neu), estrogen receptor (ER) and hypoxia-inducible factor (HIF)-1α were studied in 10 cases of ESCC treated with CCRT. The patients underwent CCRT between 2000 and 2010. The mean patient age was 68.1 years (range, 46-80 years). The numbers of patients in stages I, II, III and IV of the disease were 2, 2, 3 and 3, respectively. Of the tumors, 8 were positive for p53, 6 for p21^{waf1, 7} for MIB-1 (Ki-67), 7 for p16^INK4A, 7 for cyclin D1, 8 for E-cadherin, 3 for Bcl-2, 0 for TNF-α, 5 for NF-κB, 7 for TGF-β, 9 for MMP-7, 7 for COX-2, 5 for EGFR, 1 for HER2/neu, 1 for ER and 7 for HIF-1α. The 2-year overall survival rate of patients expressing high levels of MIB-1 was 71% (±17%) compared with 0% (P=0.019) for those expressing low levels. For NF-κB, the rate was 0% for patients with high levels compared with 100% (P<0.018) for those with low levels. The 2-year local control rates of HER2/neu were 0% in patients expressing high levels and 88% (±12%) in patients expressing low levels (P=0.027). The 2-year disease-free survival rates of HER2/neu and ER were 0% for patients expressing high levels compared with 56% (±17%) for those with low levels (P=0.027). There were no significant correlations between the expression levels of the other proteins and clinical outcomes. In the present study, high levels of MIB-1 and low levels of NF-κB, HER2 and ER were shown to be good prognostic factors following definitive CCRT for ESCC.

Inhibition of tumor growth in vitro by a combination of extracts from Rosa roxburghii Tratt and Fagopyrum cymosum

OBJECTIVE

Traditional Chinese herbal medicines have a very long history. Rosa roxburghii Tratt and Fagopyrum cymosum are two examples of plants which are reputed to have benefits in improving immune responses, enhancing digestive ability and demonstrating anti-aging effects. Some evidence indicates that herbal medicine soups containing extracts from the two in combination have efficacy in treating malignant tumors. However, the underlying mechanisms are far from well understood. The present study was therefore undertaken to evaluate anticancer effects and explore molecular mechanisms in vitro.

METHODS

Proliferation and apoptosis were assessed with three carcinoma cell lines (human esophageal squamous carcinoma CaEs-17, human gastric carcinoma SGC-7901 and pulmonary carcinoma A549) by MTT assay and flow cytometry, respectively, after exposure to extract from Rosa roxburghii Tratt (CL) and extract from Fagopyrum cymosum (FR). IC30 of CL and FR were obtained by MTT assay. Tumor cells were divided into four groups: control with no exposure to CL or FR; CL with IC30 CL; FR with IC30 FR; CL+FR group with 1/2 (IC30 CL+IC30 FR). RT-PCR and Western blot analysis were used to detect the expression of Ki-67, Bax and Bcl-2 at mRNA and protein levels.

RESULTS

Compared with the CL or FR groups, the combination of CL+FR showed significant inhibition of cell growth and increase in apoptosis; the mRNA and protein expression levels of Ki-67 and Bcl-2 in CL+FR group were all greatly decreased, while the expression of Bax was markedly increased.

CONCLUSIONS

These results indicate that the synergistic antitumor effects of combination of CL and FR are related to inhibition of proliferation and induction of apoptosis.

The relationship between tumour necrosis, tumour proliferation, local and systemic inflammation, microvessel density and survival in patients undergoing potentially curative resection of oesophageal adenocarcinoma

Background:

There is increasing evidence that the local and systemic inflammatory responses are associated with survival in oesophageal cancer. The aim of this study was to examine the relationship between tumour necrosis, tumour proliferation, local and systemic inflammation and microvessel density and survival in patients undergoing potentially curative resection of oesophageal adenocarcinoma.

Methods:

The interrelationship between tumour necrosis, tumour proliferation, local inflammatory response (Klintrup–Makinen criteria, intra-tumoural CD8+ lymphocyte and macrophage infiltration), systemic inflammatory response (modified Glasgow Prognostic score (mGPS)), and microvessel density was examined in 121 patients undergoing potentially curative resection for oesophageal adenocarcinoma (including type I and II tumours of the gastro-oesophageal junction).

Results:

Tumour necrosis was not significantly associated with any tumour measure other than the degree of differentiation. On multivariate analysis, only age (HR 1.93, 95% CI 1.23–3.04, P=0.004), mGPS (HR 2.91, 95% CI 1.51–5.62, P=0.001), positive to total lymph node ratio (HR 2.38, 95% CI 1.60–3.52, P<0.001) and macrophage infiltration (HR 1.49, 95% CI 1.02–2.18, P=0.041) were independently associated with cancer-specific survival in oesophageal adenocarcinoma. Intra-tumoural macrophages were associated with tumour proliferation (P<0.001) and CD8+ lymphocytes infiltration (P<0.01).

Conclusion:

The results of this study suggest that tumour necrosis does not link local and systemic inflammatory responses and is not significantly associated with survival. In contrast, tumour macrophage infiltration appears to have a central role in the proliferative activity and the coordination of the inflammatory cell infiltrate and is independently associated with poorer survival in patients with oesophageal adenocarcinoma.

F-18 FDG PET/CT contributes to more accurate detection of lymph nodal metastasis from actively proliferating esophageal squamous cell carcinoma

PURPOSE

Evaluating the status of disease progression is critical for planning a therapeutic strategy for esophageal cancer. In this regard, F-18 fluorodeoxyglucose-labeled positron emission tomography (PET) is one of the most useful diagnostic modalities. However, there is room to improve its diagnostic performance, such as distinguishing lymph nodal metastases from false positives. In this study, we examined the diagnostic accuracy of fluorodeoxyglucose PET accompanied by computed tomography imaging (PET/CT) to detect regional lymph nodal metastasis from esophageal squamous cell carcinoma (ESCC).

METHODS

A total of 102 patients diagnosed as ESCC were subjected to this study. These patients had a preoperative PET/CT examination to evaluate the existence of metastasis. The values of maximum standardized uptake value (SUVmax) in primary tumors and in metastasized lymph nodes were measured to analyze their relationship with various clinicopathologic characteristics including the status of tumor cell proliferation, which was assessed by immunohistochemistry for Ki-67.

RESULTS

The SUVmax of the primary tumor was positively correlated with tumor size and vessel invasion, and was positively related with the SUVmax of lymph nodal metastasis, especially in cases of poorly differentiated ESCC. The SUVmax of metastasized lymph nodes was higher in larger-sized metastasized lymph nodes, whereas the Ki-labeling index of lymph nodal metastasis was positively related with the SUVmax per unit area (SUVmax/mm). The diagnostic accuracy of PET/CT (87.3%) was higher than that of conventional CT scans (78.4%).

CONCLUSIONS

The improved diagnostic accuracy of PET/CT can be explained by its ability to detect actively progressive metastasis at an early phase regardless of size.

Prognosis of esophageal squamous cell carcinoma in patients positive for human epidermal growth factor receptor family can be improved by initial chemotherapy with docetaxel, fluorouracil, and cisplatin

BACKGROUND

The human epidermal growth factor receptor (HER) family, Ki-67 and p53 are important biomarkers for several malignancies. However, few studies have examined the role of these in prognosis and therapeutic sensitivity of esophageal squamous cell carcinoma (ESCC). The efficacy of triple-drug combination therapy with docetaxel, fluorouracil and cisplatin has recently been expected for ESCC.

METHODS

Subjects comprised 142 patients with ESCC who underwent operation (OP group, n = 54), neoadjuvant chemotherapy with docetaxel, fluorouracil, and cisplatin (DFP therapy) followed by operation (NAC group, n = 37) or initial systemic DFP therapy (CT group, n = 51) between January 2004 and December 2010. Immunohistochemical expressions of epidermal growth factor receptor (EGFR), HER2, HER3, Ki-67, and p53 were evaluated and compared with prognosis and sensitivity to DFP therapy.

RESULTS

Positive correlations existed between EGFR, HER2, and HER3 expressions. In the OP group, EGFR was independently associated with postoperative recurrence in multivariate analysis (P = .036). In the NAC group, EGFR correlated with pathological response to DFP therapy (P = .004). In the CT group, EGFR, HER2, and HER3 correlated with clinical response to DFP therapy and EGFR was independently associated with favorable prognosis in multivariate analysis (P = .022).

CONCLUSION

EGFR represents a predictor of postoperative recurrence and sensitivity to triple-drug combination therapy including a taxane. EGFR-positive patients may show improved prognosis with taxane combination chemotherapy and molecular targeted therapy for HER family members.

High expression of EZH2 is associated with tumor aggressiveness and poor prognosis in patients with esophageal squamous cell carcinoma treated with definitive chemoradiotherapy

The enhancer of zeste homolog 2 (EZH2), a known repressor of gene transcription, has been reported to be associated with biological malignancy in several cancers. The potential oncogenic role of EZH2 and its clinical/prognostic significance, however, in esophageal squamous cell carcinoma (ESCC) are unclear. In this study, the methods of immunohistochemistry and fluorescence in-situ hybridization were used to examine protein expression and amplification of EZH2 in 98 pretreatment biopsy specimens of ESCC who received definitive chemoradiotherapy (CRT). High expression of EZH2 and amplification of EZH2 was found in 54.1% and 12.0% of ESCCs, respectively. High EZH2 expression was significantly correlated with increased cell proliferation (p = 0.009), high histopathological grade (p = 0.002), regional (p = 0.025) and distant lymph node metastasis (p < 0.001) and lack of clinical complete response to CRT (p = 0.028). Univariate analysis revealed that high expression of EZH2 was associated with poor metastasis-free survival (MFS) (p = 0.003), poor progression-free survival (PFS) (p = 0.001) and poor disease-specific survival (DSS) (p < 0.001). In multivariate analysis, high expression of EZH2, together with lack of clinical complete response, were evaluated as significant independent prognostic factors of MFS, PFS and DSS for patients with ESCC. These findings suggest that high expression of EZH2 correlates with tumor aggressiveness and adverse patient outcome in ESCC treated with definitive CRT. Evaluation of EZH2 expressions might be useful for predicting tumor response to CRT and prognosis for patients with ESCC.

Factors influencing the long-term survival in patients with esophageal cancer who underwent esophagectomy after chemoradiotherapy

BACKGROUND

Salvage esophagectomy is potentially the only treatment available that can offer a chance of long-term survival when definitive chemoradiotherapy (CRT) fails to achieve local control for patients with esophageal squamous cell carcinoma (ESCC). However, salvage esophagectomy is a highly invasive procedure with various postoperative complications compared to planned esophagectomy after neoadjuvant chemoradiotherapy (CRT). We hypothesize that severe postoperative complications may affect not only surgical mortality but also tumor recurrence and long-term survival for patients with salvage esophagectomy after definitive CRT.

METHODS

For the present study we reviewed the surgical procedures, postoperative complications, and the prognosis of 65 consecutive patients with thoracic ESCC who underwent the esophagectomy after neoadjuvant (neoadjuvant group: n = 40) or definitive (salvage group: n = 25) CRT.

RESULTS

Most patients underwent right-transthoracic extended esophagectomy and reconstruction using gastric conduit by way of subcutaneous route with left cervical anastomosis. The incidence of postoperative pneumonia was found to be higher in the salvage group than in the neoadjuvant group. In both groups, the survival of patients with R0 resection was significantly better than those with R1/R2 resection. Moreover, in the salvage group, the postoperative survival rate of patients with pneumonia or bacteremia/sepsis was significantly lower than that for patients who did not suffer the same complications. In the neoadjuvant group, R0 resection was selected to be the only independent prognostic factor in univariate and multivariate analysis. In contrast, in the salvage group, R0 resection and bacteremia/sepsis remained significant and were independent of the other factors in multivariate analysis.

CONCLUSIONS

This study reveals that postoperative morbidity affects not only the perioperative mortality but also the long-term survival of patients with ESCC who undergo salvage esophagectomy after definitive CRT.

Expression and clinical significance of EGFL7 in malignant glioma

PURPOSE

Tumor angiogenesis is an important factor for the continuous growth of human malignancies and can be used to predict the prognosis for patients. In the current study, we examined the expression of EGF-like domain 7 (EGFL7), an endothelial cell-derived secreted factor, in malignant gliomas and explored its clinical significance.

METHODS

We determined the steady-state mRNA levels of EGFL7 from 36 fresh glioma samples by semi-quantitative RT-PCR and the protein levels from 45 paraffin-embedded glioma samples by immunohistochemistry, respectively. Normal brain tissues from 10 patients with brain trauma were used as control. We also analyzed the correlations between the expression levels of EGFL7 and various clinical parameters, including patient gender, age, tumor grade, tumor proliferation marker Ki-67, and microvessel density (MVD).

RESULTS

We found that EGFL7 was not detectable in normal brain tissues, but was up-regulated in both tumor cells and vascular endothelial cells within malignant glioma. The expression level of EGFL7 in malignant glioma significantly correlated with the tumor grade, Ki-67 expression and MVD (P < 0.01).

CONCLUSIONS

Our data suggest that EGFL7 expression is a novel predictive factor for the clinical progression of malignant glioma, and may constitute a therapeutic target for anti-angiogenesis therapy in patients with the disease.

Collagenous myofibroblastic tumor of the mandible: case report of a unique locally aggressive neoplasm

We report a locally aggressive collagenous myofibroblastic neoplasm of the mandible in an 18-year-old male. Clinically, the lesion presented with rapid growth and irregular mandibular bone destruction. Grossly, the tumor was 10 cm in greatest dimension, light-tan, firm, and involving the posterior one-thirds of the body and inferior half of the left mandibular ramus. Histologically, the lesion was composed of a loose spindle cell proliferation interspersed with periodic dense bands of collagen. The spindle cells reacted positively to smooth muscle actin, calponin, and focally to desmin and were negative for S-100, pan-cytokeratin, CD99, CD34 and caldesmon, supporting myofibroblastic derivation. At our 4 year follow-up, the patient remained free of local recurrence and surgery related complications. The clinicopathologic findings and the differential diagnosis of this lesion is presented and discussed.

Overexpression of AIB1 predicts resistance to chemoradiotherapy and poor prognosis in patients with primary esophageal squamous cell carcinoma

AIB1 (amplified in breast cancer 1) is frequently overexpressed in esophageal squamous cell carcinoma (ESCC), but the significance of AIB1 expression in chemoradiotherapy (CRT) sensitivity and its effect on prognosis are still unclear. In this study, the expression of AIB1 was examined by immunohistochemistry in 98 biopsy specimens of primary ESCC patients treated with definitive CRT. AIB1 overexpression was found in 63/98 (64.3%) of the ESCCs. There was a significant association between AIB1 overexpression and distant lymph node metastases (P = 0.011), but not regional lymph node metastases. In the M0 subgroup, overexpression of AIB1 was observed more frequently in stage T4 than in stage T2-3 (66.7%vs 38.5%, P = 0.031). In addition, AIB1 expression was the only factor that showed a significant correlation with CRT response, in which overexpression of AIB1 was observed more frequently in the CRT resistant group than in the CRT effective group (86.5%vs 50.8%, P < 0.001). Univariate analysis revealed that AIB1 overexpression was associated with poor progression-free survival (PFS) (P < 0.001) and poor disease-specific survival (DSS) (P <0.001). Furthermore, AIB1 expression could stratify patient survival in stages T2-3, T4, N1, and M0 (P < 0.05), as well as in the CRT effective group (P < 0.05), and AIB1 overexpression and CRT resistance were evaluated as significant independent prognostic factors for both PFS and DSS in multivariate analysis. These findings suggest that overexpression of AIB1 is a useful predictor of CRT resistance and an independent molecular marker of poor prognosis for ESCC patients.

REG I enhances chemo- and radiosensitivity in squamous cell esophageal cancer cells

Identification of reliable markers of chemo- and radiosensitivity and the key molecules that enhance the susceptibility of squamous esophageal cancer cells to anticancer treatments would be highly desirable. To test whether regenerating gene (REG) I expression enhances chemo- and radiosensitivity in esophageal squamous cell carcinoma cells, we used MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assays to compare the chemo- and radiosensitivities of untransfected TE-5 and TE-9 cells with those of cells stably transfected with REG Ialpha and Ibeta. We then used flow cytometry to determine whether REG I expression alters cell cycle progression. No REG I mRNA or protein were detected in untransfected TE-5 and TE-9 cells. Transfection with REG Ialpha and Ibeta led to strong expression of both REG I mRNA and protein in TE-5 and TE-9 cells, which in turn led to significant increases in both chemo- and radiosensitivity. Cell cycle progression was unaffected by REG I expression. REG I thus appears to enhance the chemo- and radiosensitivity of squamous esophageal cancer cells, which suggests that it may be a useful target for improved and more individualized treatments for patients with esophageal squamous cell carcinoma.

REG Ialpha is a reliable marker of chemoradiosensitivity in squamous cell esophageal cancer patients

BACKGROUND

A reliable marker of chemoradiosensitivity that would enable appropriate and individualized treatment of thoracic squamous cell esophageal cancer has long been sought. We investigated whether regenerating gene (REG) Ialpha is such a marker.

METHODS

We assessed expression of REG Ialpha in untreated endoscopic biopsy specimens and examined the correlation between REG Ialpha expression and the clinical responses to definitive chemoradiotherapy and prognosis. We also examined the relationship between REG Ialpha expression in the resected tumor and the prognosis of patients who received esophagectomy for thoracic squamous cell esophageal cancer.

RESULTS

Among the 42 patients treated with definitive chemoradiotherapy, 8 of the 23 REG I-positive patients (35%) showed complete responses to chemoradiotherapy, while only one of the 19 REG I-negative patients did so. The survival rate among the REG I-positive patients was significantly better than among the REG I-negative patients. For the 76 patients treated surgically, there was no significant difference in the survival rates among the REG I-positive and REG I-negative patients.

CONCLUSIONS

REG Ialpha expression in squamous cell esophageal carcinoma may be a reliable marker of chemoradiosensitivity. We anticipate that it will enable us to provide more appropriate and individualized treatment to patients of advanced esophageal squamous cell carcinoma.

Pretreatment plasma fibrinogen level correlates with tumor progression and metastasis in patients with squamous cell carcinoma of the esophagus

BACKGROUND

Hypercoagulation has been reported to be associated with tumor progression and a poor prognosis in various carcinomas. In this study, we examined fibrinogen levels in pretreated patients with esophageal squamous cell carcinoma (ESCC) and assessed its correlation with clinicopathological factors and prognosis in patients with ESCC.

METHODS

Pretreatment fibrinogen levels were examined prior to surgery or other treatments (e.g. endoscopic mucosal resection and chemoradiotherapy [CRT]) in 105 patients with primary ESCC. We investigated the association of fibrinogen levels with clinicopathological background factors and the survival of ESCC patients.

RESULTS

The plasma fibrinogen concentration (PFC) ranged from 209.4 to 781.6 mg/dL. Pretreatment PFC correlated significantly with the depth of invasion (T factor). There also existed a significant correlation between higher fibrinogen levels and lymph node metastasis (N factor) and distant organ metastasis. Patients with a higher fibrinogen level experienced a significantly worse overall survival (P = 0.006). Fibrinogen levels strongly correlated with platelet counts, white blood cell counts and tumor length. Pretreatment PFC were observed to have a significant correlation with CRT responsiveness in ESCC patients in stages II and III (P = 0.005).

CONCLUSION

This study revealed that higher levels of fibrinogen correlated with tumor progression, metastasis and poor responsiveness to CRT in ESCC patients.

Correlation between tumor blood flow assessed by perfusion CT and effect of neoadjuvant therapy in advanced esophageal cancers

BACKGROUND

Redundant blood supply by angiogenesis is a great advantage for the continuous growth of solid tumors. However, with chemotherapy (ChT), it can be disadvantageous due to increased drug delivery. An objective, reproducible, and non-invasive method for evaluating tumor blood supply is offered by perfusion CT.

METHODS

Fifty-five advanced esophageal cancers (95% squamous cell carcinomas) were evaluated for hemodynamic parameters, including blood flow (BF), blood volume (BV), and mean transit time (MTT) of primary tumor by perfusion CT scan. Forty-six underwent neoadjuvant therapy (36 ChT and 10 chemoradiotherapy (CRT)) as primary treatment of the cancer and 36 underwent esophagectomy.

RESULTS

Clinicopathological parameters were not significantly associated with hemodynamic parameters, except for hematogenic metastasis, which was not frequent (seven patients), but significantly associated with high BF (P = 0.0165). High BF and low MTT correlated significantly with a good response by neoadjuvant therapies (P = 0.0004 and P = 0.0124), while BV did not. The patients with high BF more frequently underwent esophagectomy and displayed better prognosis than those with lower values, while neither BV nor MTT was associated with patient survival.

CONCLUSIONS

Tumor BF by perfusion CT can partly predict the effect of ChT and CRT and survival. Further large cohort studies in homogeneous patient groups will reveal its clinical usefulness.

REG I expression predicts long-term survival among locally advanced thoracic squamous cell esophageal cancer patients treated with neoadjuvant chemoradiotherapy followed by esophagectomy

BACKGROUND

The prognosis for patients with locally advanced thoracic esophageal cancer is extremely unfavorable. We have been administering neoadjuvant chemoradiotherapy (CRT) followed by esophagectomy to these patients and studying whether REG I expression in untreated endoscopic biopsy specimens is predictive of patient responsiveness to CRT and/or survival after treatment.

METHODS

Between 1992 and 2003, 47 patients with T4 (direct invasion of adjacent organs) thoracic esophageal cancers were administered neoadjuvant CRT followed by esophagectomy. REG I expression was assessed in untreated endoscopic biopsy specimens and correlated with clinical and histological responses and survival in 37 patients who had also undergone curative surgery.

RESULTS

Among the 37 cases that received CRT followed by surgery, the therapeutic response rate for neoadjuvant CRT was 68%, and a complete histological response in resected specimens from the primary lesion was achieved in 8 (22%) patients. These clinical and histological responses to neoadjuvant CRT did not significantly correlate with survival, however. By contrast, 9 patients were judged REG-positive based on analysis of their untreated endoscopic biopsy specimens, and their cumulative survival rate was significantly higher than that of the 28 REG-negative patients (P = 0.0073). Univariate analysis showed REG I expression to be a prognostic factor (P = 0.0386) that increased the risk of death 8.4-fold.

CONCLUSIONS

Evaluation of REG I expression in untreated endoscopic biopsy specimens may provide a basis for new treatments of locally advanced thoracic squamous cell esophageal cancers.

Cyclin D1 overexpression in esophageal cancer from southern China and its clinical significance

Little reports showed cyclin D1 changes in esophageal cancer from southern China. In this study, we detected cyclin D1 expression in esophageal carcinomas from southern China 61% and 35% cases showed increased expression of cyclin D1 in esophageal carcinomas and the adjacent epithelia, respectively. Significant difference for cyclin D1 expression was found between esophageal carcinomas and the adjacent epithelia. Comparing cyclin D1 expression in the carcinomas at different stages, we found significant alterations. The results suggested that cyclin D1 was involved in the earlier event and accumulated as the cancer evolved to a later stage in some esophageal carcinomas.

Relationship between proliferative activity of cancer cells and clinicopathological factors in patients with esophageal squamous cell carcinoma

AIM: To assess whether the molecular markers of malignant tumors could improve the understanding of tumor charact-eristics, and to observe the characteristics of expression of cell cycle markers Ki-67 and cyclin A in esophageal carcinoma and to analyze the relationship between proliferative activity of cancer cells and clinicopathological factors.

METHODS: Seventy of surgically resected esophageal squamous cell carcinoma (SCC) were examined by immun-ohistochemistry utilizing commercially available antibodies. Nuclear staining was regarded as a positive result. At least 50 fields in each tumor and non-tumor section were evaluated at a medium power (×200) to determine the proportion of tumor cells and the staining intensity of nuclei in the entire sections.

RESULTS: Ki-67 and cyclin A were only expressed in base cells of normal esophageal mucosa. The positive immuno-staining of nuclei of SCC was significantly higher than that in normal esophageal mucosa (t = 13.32 and t = 7.52, respectively, P<0.01). The distribution of positively stained was more diffuse and stronger in poorly differentiated SCC. Both Ki-67 and cyclin A expressions were related to histological grades of tumors (t = 3.5675 and t = 3.916; t = 2.13, respectively, P<0.05) but not to the sex and age of the patients, tumor size, lymphatic invasion, location, or stage grouping.

CONCLUSION: The proliferative activity of cancer cells may be understood by immunohistochemistry of Ki-67 and cyclin A in Chinese patients with esophageal SCC. These cell cycle markers may serve as an indicator of cancer cell proliferation rate. The overexpression of cell cycle markers Ki-67 and cyclin A suggests the poor SCC differentiation in patients with esophageal carcinoma.

Reduced tumor vessel density and high expression of glucose transporter 1 suggest tumor hypoxia of squamous cell carcinoma of the esophagus surviving after radiotherapy

BACKGROUND

Squamous cell carcinoma of the esophagus (ESCC) is radiosensitive; however, surgeons frequently encounter ESCC that survives radiotherapy to grow more rapidly and invasively. This alteration of tumor behavior may result from tumor hypoxia induced by radiotherapy.

METHODS

Forty-four patients with advanced (T3 and T4) ESCC, who underwent radiotherapy before operation, either with 40 Gy for preoperative treatment or 60 Gy or more for radical treatment, and 44 patients without preoperative therapy were subjected to retrospective immunohistochemical study. CD34 for tumor vessels, glucose transporter 1 (GLUT1) which was induced by hypoxia, MIB-1 for proliferating activity, and p53 were stained for surgical samples from ESCC patients. Tumor tissue at the invading front was the focus of evaluation. Macroscopic morphologic differences of ESCC were also evaluated.

RESULTS

Loss of esophageal wall thickness and deep ulceration were morphologic characteristics of ESCC after radiotherapy. Tumor vessel density was reduced and GLUT1 expression was greater in the ESCC after radiotherapy than in those without treatment. Tumor vessel density was similar for both preoperative and radical radiotherapy samples, while GLUT1 expression tended to be greater in the latter than in the former. The expression of MIB-1 and p53 did not show any significant difference between ESCC with or without radiotherapy.

CONCLUSIONS

Reduced vessel density and increased GLUT1 expression suggested tumor hypoxia for ESCC occurred after radiotherapy. Tumor hypoxia would induce ulcerative and invasive growth, which is a great obstacle to clinical treatment of residual or relapse ESCC after radiotherapy.

Mechanistic and predictive profiling of 5-Fluorouracil resistance in human cancer cells

Gene expression was analyzed in five pairs of 5-fluorouracil (5-FU) resistant and parental cancer cell lines on DNA microarrays. In unsupervised analysis, a prediction rule was built from the expression profiles of 29 genes, and 5-FU sensitivity class was predicted with 100% accuracy and high predictive strength. In supervised analysis of key 5-FU pathways, expression of 91 genes was associated with 5-FU sensitivity phenotype and segregated samples accordingly in hierarchical analysis. Key genes involved in 5-FU activation were significantly down-regulated (thymidine kinase, 2.9-fold; orotate phosphoribosyltransferase, 2.3-fold; uridine monophosphate kinase, 3.2-fold; pyrimidine nucleoside phosphorylase 3.6-fold) in resistant cells. Overexpression of thymidylate synthase and its adjacent gene, c-Yes, was detected in the resistant cell lines. The mRNA and protein overexpression of nuclear factor kappaB (NFkappaB) p65 and related antiapoptotic c-Flip gene was detected in resistant cells. The 5-FU-resistant cell lines also showed high NFkappaB DNA-binding activity. Cotransfection of NFkappaB p50 and p65 cDNA induced 5-FU resistance in MCF-7 cells. Both NFkappaB- and 5-FU-induced resistant cell lines manifested reduced expression of genes governing G(1)-S and S-phase transition. Expression of genes involved in DNA replication was also down-regulated in resistant cell lines. These findings were highly consistent with the slower growth rate, higher proportion of G(1), and lower proportion of S-phase cells in the resistant cell lines. This phenotype may protect resistant cells from cell death induced by incorporation of 5-FU into DNA chains, by allowing time to repair 5-FU-induced damage. Our findings may provide novel targets for tackling 5-FU resistance.