Personalized treatment of colorectal cancer

Identification of a novel prognostic signature composed of 3 cuproptosis-related transcription factors in colon adenocarcinoma

BACKGROUND

Since the mechanism of cuproptosis was recently revealed, many molecules related to this pathway have been widely concerned and exploited to have prognostic potential. However, it is still unknown whether the transcription factors related to cuproptosis could be competent as tumor biomarkers of colon adenocarcinoma (COAD).

OBJECTIVE

To analyze the prognostic potential of cuproptosis-related transcription factors in COAD, and validate the representative molecule.

METHODS

Transcriptome data and patients' clinical parameters were obtained from the TCGA and GEO database. 19 cuproptosis genes were identified through literature consulting. Cuproptosis-related transcription factors were screened by COX regression analyses. Multivariate Cox regression was applied to construct the signature. Prognostic effects were evaluated by Kaplan Meier survival analyses and ROC analyses. KEGG, GO, and ssGSEA analyses were performed for function prediction. 48 COAD tissues were collected for immunohistochemistry stain to observe the expression level and prognostic value of E2F3. qRT-PCR was performed to detect mRNA expression levels, while cell viability assay was applied to detect the response of COAD cells to elesclomol treatment.

RESULTS

A novel signature based on 3 prognostic transcription factors related to cuproptosis was successfully established and verified. Patients in the low-risk group tended to have better overall survival and lower immune phenotype scores than those in the high-risk group. Meanwhile, we also constructed a nomogram based on this signature and predict 10 candidate compounds targeting this signature. As an essential member of this signature, E2F3 was confirmed to be overexpressed in COAD tissues and was associated with poor prognosis of COAD patients. Importantly, CuCl2 and cuproptosis inducer elesclomol treatment could increase the expression of E2F3 in COAD cell while the overexpression of E2F3 significantly enhanced the resistance of COAD cells to elesclomol treatment.

CONCLUSION

Our research has identified a new prognostic biomarker and provides some innovative insights into the diagnosis and therapy of patients with COAD.

Deep-learning model for predicting the survival of rectal adenocarcinoma patients based on a surveillance, epidemiology, and end results analysis

Background

We collected information on patients with rectal adenocarcinoma in the United States from the Surveillance, Epidemiology, and EndResults (SEER) database. We used this information to establish a model that combined deep learning with a multilayer neural network (the DeepSurv model) for predicting the survival rate of patients with rectal adenocarcinoma.

Methods

We collected patients with rectal adenocarcinoma in the United States and older than 20 yearswho had been added to the SEER database from 2004 to 2015. We divided these patients into training and test cohortsat a ratio of 7:3. The training cohort was used to develop a seven-layer neural network based on the analysis method established by Katzman and colleagues to construct a DeepSurv prediction model. We then used the C-index and calibration plots to evaluate the prediction performance of the DeepSurv model.

Results

The 49,275 patients with rectal adenocarcinoma included in the study were randomly divided into the training cohort (70%, n = 34,492) and the test cohort (30%, n = 14,783). There were no statistically significant differences in clinical characteristics between the two cohorts (p > 0.05). We applied Cox proportional-hazards regression to the data in the training cohort, which showed that age, sex, marital status, tumor grade, surgery status, and chemotherapy status were significant factors influencing survival (p < 0.05). Using the training cohort to construct the DeepSurv model resulted in a C-index of the model of 0.824, while using the test cohort to verify the DeepSurv model yielded a C-index of 0.821. Thesevalues show that the prediction effect of the DeepSurv model for the test-cohort patients was highly consistent with the prediction resultsfor the training-cohort patients.

Conclusion

The DeepSurv prediction model of the seven-layer neural network that we have established can accurately predict the survival rateand time of rectal adenocarcinoma patients.

DNA protein crosslink proteolysis repair: From yeast to premature ageing and cancer in humans

DNA-protein crosslinks (DPCs) are a specific type of DNA lesion consisting of a protein covalently and irreversibly bound to DNA, which arise after exposure to physical and chemical crosslinking agents. DPCs can be bulky and thereby pose a barrier to DNA replication and transcription. The persistence of DPCs during S phase causes DNA replication stress and genome instability. The toxicity of DPCs is exploited in cancer therapy: many common chemotherapeutics kill cancer cells by inducing DPC formation.

Recent work from several laboratories discovered a specialized repair pathway for DPCs, namely DPC proteolysis (DPCP) repair. DPCP repair is carried out by replication-coupled DNA-dependent metalloproteases: Wss1 in yeast and SPRTN in metazoans. Mutations in SPRTN cause premature ageing and liver cancer in humans and mice; thus, defective DPC repair has great clinical ramifications. In the present review, we will revise the current knowledge on the mechanisms of DPCP repair and on the regulation of DPC protease activity, while highlighting the most significant unresolved questions in the field. Finally, we will discuss the impact of faulty DPC repair on disease and cancer therapy.

Survival of patients with non-resectable, chemotherapy-resistant colorectal cancer liver metastases undergoing conventional lipiodol-based transarterial chemoembolization (cTACE) palliatively versus neoadjuvantly prior to percutaneous thermal ablation

PURPOSE

To determine overall (OS) and progression-free survival (PFS) for cTACE alone and in combination with percutaneous thermal ablation in patients with non-resectable, chemotherapy-resistant colorectal cancer liver metastases (CRLM).

MATERIAL AND METHODS

The study included 452 patients undergoing 2654 repetitive cTACE treatments of CRLM. 233 patients were treated palliatively using only cTACE, whereas 219 patients were treated with cTACE in a neoadjuvant intend with subsequent thermal ablation (either microwave ablation or laser-induced thermotherapy). The chemotherapeutics agents used, in either single-, double-, or triple-combinations, included MitomycinC, Gemcitabine, Irinotecan, and Cisplatin. Several factors were analysed to determine their prognostic value in terms of OS and PFS.

RESULTS

Palliative use of cTACE resulted in a median OS and PFS of 12.6 and 5.9 months, whereas the neoadjuvant use of cTACE showed a median OS and PFS of 25.8 and 10.8 months. The differences in OS and PFS between the two groups were statistically significant (p < 0.001). Extrahepatic metastases were a significant prognostic factor in the OS and PFS analysis of the palliative and neoadjuvant group. In addition, number, location, and mean size of metastases were significant prognostic factors for OS and PFS in the neoadjuvant group. Sex, primary tumor location, T- and N-parameters of the TNM staging system, time of liver metastases appearance, ablation method, and patient age did not significantly impact OS and PFS in either patient group. The most distinct response to cTACE was observed in metastases that were treated with a triple-combination of chemotherapeutics (p = 0.021).

CONCLUSION

cTACE is an effective treatment option in advanced non-resectable CRLM. Chemoembolization followed by ablation further increases survival rates. A triple combination of chemotherapeutics improves response to cTACE.

[Local ablative radiotherapy of oligometastatic colorectal cancer]

BACKGROUND

Colorectal cancer (CRC) often presents as oligometastatic disease. Currently available intensive systemic treatment regimens, including combination chemotherapy and molecular targeted agents, result in tumor response and transient to long-term disease control in a high percentage of patients, thus raising the question of further management. Secondary resection and ablation, e.g. by surgery or radiofrequency may contribute to long-term survival and even be curative or at least allow a relevant chemotherapy-free interval. These approaches are often limited by the anatomical site, invasiveness and morbidity of the respective procedure. With stereotactic body radiotherapy (SBRT) metastases can be treated with very high efficiency in only a few sessions and achieving long-term control.

OBJECTIVES

Identification of clinical studies investigating the use of SBRT for treatment of oligometastases in CRC patients. Control rates in liver and lung metastases and survival after SBRT. Toxicity and side effects of the treatment.

MATERIAL AND METHODS

A literature search was carried out for prospective and retrospective studies on local SBRT.

RESULTS AND CONCLUSION

The SBRT procedure has become a valid treatment option for patients with oligometastatic CRC and should also be considered in clinical practice as an alternative to surgical treatment of metastases or other local ablative techniques.

Molecular characterization of irinotecan (SN-38) resistant human breast cancer cell lines

Background

Studies in taxane and/or anthracycline refractory metastatic breast cancer (mBC) patients have shown approximately 30 % response rates to irinotecan. Hence, a significant number of patients will experience irinotecan-induced side effects without obtaining any benefit. The aim of this study was to lay the groundwork for development of predictive biomarkers for irinotecan treatment in BC.

Methods

We established BC cell lines with acquired or de novo resistance to SN-38, by exposing the human BC cell lines MCF-7 and MDA-MB-231 to either stepwise increasing concentrations over 6 months or an initial high dose of SN-38 (the active metabolite of irinotecan), respectively. The resistant cell lines were analyzed for cross-resistance to other anti-cancer drugs, global gene expression, growth rates, TOP1 and TOP2A gene copy numbers and protein expression, and inhibition of the breast cancer resistance protein (ABCG2/BCRP) drug efflux pump.

Results

We found that the resistant cell lines showed 7–100 fold increased resistance to SN-38 but remained sensitive to docetaxel and the non-camptothecin Top1 inhibitor LMP400. The resistant cell lines were characterized by Top1 down-regulation, changed isoelectric points of Top1 and reduced growth rates. The gene and protein expression of ABCG2/BCRP was up-regulated in the resistant sub-lines and functional assays revealed BCRP as a key mediator of SN-38 resistance.

Conclusions

Based on our preclinical results, we suggest analyzing the predictive value of the BCRP in breast cancer patients scheduled for irinotecan treatment. Moreover, LMP400 should be tested in a clinical setting in breast cancer patients with resistance to irinotecan.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2071-1) contains supplementary material, which is available to authorized users.

Expression of AQP5 and AQP8 in human colorectal carcinoma and their clinical significance

Background

The aquaporins (AQPs) are a family of small membrane transport proteins whose overexpression has been implicated in tumorigenesis. However, the expression of AQP5 and AQP8 in colorectal cancer and the clinical significance remain unexplored. This study aimed to detect the expression of AQP5 and AQP8 in clinical samples of colorectal cancer and analyze the correlations of their expression with the clinicopathological features of colorectal cancer.

Methods

Forty pairs of colorectal cancer tissue and paraneoplastic normal tissue were obtained at the time of surgery from patients with colorectal cancer. The expression of AQP5 and AQP8 was detected by immunohistochemical staining and reverse transcriptase polymerase chain reaction.

Results

AQP5 was mainly expressed in colorectal carcinoma cells and barely expressed in paraneoplastic normal tissues. By contrast, AQP8 was mainly expressed in paraneoplastic normal tissues and barely expressed in colorectal carcinoma cells. AQP5 expression was not significantly associated with the sex or age of the patient with colorectal cancer (P>0.05), but was closely associated with the differentiation, tumor-nodes-metastasis stage and distant lymph node metastasis of colorectal carcinoma (P<0.05).

Conclusions

AQP5 might be a novel prognostic biomarker for patients with colorectal cancer.

Changes in specialized blood vessels in lymph nodes and their role in cancer metastasis

Background

High endothelial venules (HEV) have been recognized to play a role in metastasis by its changes seen in the cancer microenvironment of lymph nodes (LN) and solid cancers. Squamous cell carcinoma (SCC) of the tongue is a prevalent tumor of the head and neck region with high propensity for LN metastasis. The extent of LN metastasis is the most reliable adverse prognostic factor. Primary tumors can induce vasculature reorganization within sentinel LN before the arrival of tumor cells and HEV represents these remodelled vessels. This study aims to evaluate the cancer induced vascular changes in regional lymph nodes (LN) of patients by studying the morphological and functional alterations of HEV and its correlation with clinical outcome and pathological features.

Methods

This study was based on 65 patients with SCC tongue who underwent primary surgical treatment including neck dissection. The patients were categorized into 2 groups based on the presence of malignancy in their cervical lymph nodes. A review of the patients' pathological and clinical data was performed from a prospective database. Immunohistochemical staining of the tissue blocks for HEV and high-power-field image analysis were performed and analyzed with correlation to the patients' clinical and pathological features.

Results

The total number of HEV was found to be significantly associated to disease-free interval. There was a similar association comparing the HEV parameters to overall survival. The density of abnormal HEV was significantly higher in patients with established metastases in their lymph nodes and HEV was shown to be a better prognosis factor than conventional tumor staging. The HEV morphological metamorphosis demonstrates a spectrum that correlates well with disease progression and clinical outcome.

Conclusions

The results suggest that the HEV displays a spectrum of morphological changes in the presence of cancer and LN metastasis, and that HEV is possibly involved in the process of cancer metastasis. We revealed the relationship of HEV and their metamorphosis in pre-metastatic and metastatic environments in regional lymph nodes of tongue cancer patients in relation to clinical outcomes. The significant observation of modified dilated HEV containing red blood cells in lymph nodal basin of a cancer suggests the shifting of its function from one primarily of immune response to that of a blood carrying vessel. It also demonstrated potential prognostic value. More studies are needed to elucidate its potential role in cancer immunotherapy and as a potential novel therapeutic approach to preventing metastasis by manipulating the remodelling processes of HEV.