The prognostic and predictive value of selected biomarkers in colorectal cancer

Tissue-based biomarkers are studied to receive information about the pathologic processes and cancer outcome, and to enable development of patient-tailored treatments. The aim of this study was to investigate the potential prognostic and/or predictive value of selected biomarkers in colorectal cancer (CRC). Group IIA secretory phospholipase A2 (IIA PLA2) expression was assessed in 114 samples presenting different phases of human colorectal carcinogenesis. Securin, Ki-67, CD44 variant 6 (CD44v6), aldehyde dehydrogenase 1 (ALDH1) and β-catenin were studied in a material including 227 rectal carcinoma patients treated with short-course preoperative radiotherapy (RT), long-course preoperative (chemo)RT (CRT) or surgery only. Epidermal growth factor receptor (EGFR) gene copy number (GCN), its heterogeneity in CRC tissue, and association with response to EGFR-targeted antibodies cetuximab and panitumumab were analyzed in a cohort of 76 metastatic CRC. IIA PLA2 expression was decreased in invasive carcinomas compared to adenomas, but did not relate to patient survival. High securin expression after long-course (C)RT and high ALDH1 expression in node-negative rectal cancer were independent adverse prognostic factors, ALDH1 specifically in patients treated with adjuvant chemotherapy. The lack of membranous CD44v6 in the rectal cancer invasive front associated with infiltrative growth pattern and the risk of disease recurrence. Heterogeneous EGFR GCN increase predicted benefit from EGFR-targeted antibodies, also in the chemorefractory patient population. In summary, high securin and ALDH1 protein expression independently relate to poor outcome in subgroups of rectal cancer patients, potentially because of resistance to conventional chemotherapeutics. Heterogeneous increase in EGFR GCN was validated to be a promising predictive factor in the treatment of metastatic CRC.Valikoitujen merkkiaineiden ennusteellinen merkitys paksu- ja peräsuolisyövässä Kudoslähtöisten merkkiaineiden tutkimisella toivotaan voivan saavuttaa lisätietoa syövän biologisesta käyttäytymisestä ja ennusteesta, sekä mahdollistaa kullekin potilaalle optimaalisen hoidon valinnan. Väitöstutkimuksen tavoitteena oli selvittää valikoitujen merkkiaineiden ennusteellista merkitystä paksu- ja peräsuolisyövässä. Tyypin II sekretorisen fosfolipaasi A2:n (IIA PLA2) ilmentymistä tutkittiin 114:ssä syövän kehittymisen eri vaiheita edustavassa paksu- ja peräsuolikasvaimessa. Securinin, Ki-67:n, CD44 variantti 6:n (CD44v6), aldehydidehydrogenaasi 1:n (ALDH1) ja β-kateniinin ilmentymistä analysoitiin 227 peräsuolisyöpäpotilaan aineistossa, jossa oli mukana myös ennen leikkausta (kemo)sädehoidettuja potilaita. Levinnyttä paksu- tai peräsuolisyöpää sairastavien potilaiden (n=76) leikkausnäytteistä tutkittiin epidermaalisen kasvutekijäreseptorin (EGFR) geenikopiomäärää, sen kasvaimen sisäistä vaihtelua, sekä yhteyttä EGFR-vasta-ainehoidoista saavutettavaan hyötyyn. IIA PLA2:n ilmentyminen syövässä oli vähäisempää kuin syövän esiasteissa. Securinin korkea ilmentyminen pitkän (kemo)sädehoidon jälkeen, sekä ALDH1:n korkea ilmentyminen imusolmukkeisiin leviämättömässä peräsuolisyövässä olivat itsenäisiä huonon ennusteen tekijöitä, ALDH1 etenkin solunsalpaajilla hoidetuilla potilailla. Heikentynyt solukalvon CD44v6-ilmentyminen oli yhteydessä syövän aggressiiviseen kasvutapaan ja peräsuolisyövän uusiutumisriskiin. Heterogeeninen EGFR-geenin kopiomäärän lisääntyminen ennusti hyvää vastetta EGFR-vasta-ainehoidoille levinneessä paksu- ja peräsuolisyövässä, mikä oli nähtävissä myös solunsalpaajahoidoille kehittyneen vastustuskyvyn jälkeisissä hoitolinjoissa. Yhteenvetona todetaan, että korkea securinin ja ALDH1:n ilmentyminen peräsuolisyövässä ovat itsenäisiä huonon ennusteen merkkejä tietyissä alaryhmissä. Tämä voi heijastaa securin- ja ALDH1-positiivisten syöpäsolujen vastustuskykyä yleisesti käytetyille solunsalpaajille. Heterogeeninen EGFR-geenikopiomäärän lisääntyminen on lupaava tekijä ennustamaan EGFR-vasta-ainehoidoista saavutettavaa kliinistä hyötyä.Siirretty Doriast

Protein phosphatase 2A (PP2A) inhibitor CIP2A indicates resistance to radiotherapy in rectal cancer

Preoperative (chemo)radiotherapy, (C)RT, is an essential part of the treatment of rectal cancer patients, but tumor response to this therapy among patients is variable. Thus far, there are no clinical biomarkers that could be used to predict response to (C)RT or to stratify patients into different preoperative treatment groups according to their prognosis. Overexpression of cancerous inhibitor of protein phosphatase 2A (CIP2A) has been demonstrated in several cancers and is frequently associated with reduced survival. Recently, high CIP2A expression has also been indicated to contribute to radioresistance in head and neck squamous cell carcinoma, but few studies have examined the connection between CIP2A and radiation response regarding other malignancies. We have evaluated CIP2A protein expression levels in relation to tumor regression after preoperative (C)RT and survival of rectal adenocarcinoma patients. The effects of CIP2A knockdown by siRNA on cell survival were further investigated in colorectal cancer cells exposed to radiation. Patients with low-CIP2A-expressing tumors had more frequently moderate or excellent response to long-course (C)RT than patients with high-CIP2A-expressing tumors. They also had higher 36-month disease-specific survival (DSS) rate in categorical analysis. In the multivariate analysis, low CIP2A expression level remained as an independent predictive factor for increased DSS. Suppression of CIP2A transcription by siRNA was found to sensitize colorectal cancer cells to irradiation and decrease their survival in vitro. In conclusion, these results suggest that by contributing to radiosensitivity of cancer cells, low CIP2A protein expression level associates with a favorable response to long-course (C)RT in rectal cancer patients.</p

Heterogeneous EGFR Gene Copy Number Increase Is Common in Colorectal Cancer and Defines Response to Anti-EGFR Therapy

Peer reviewe

EGFR gene copy number decreases during anti-EGFR antibody therapy in colorectal cancer

Epidermal growth factor receptor (EGFR) gene copy number (GCN) increase is associated with a favorable anti-EGFR antibody treatment response in RAS wild-type metastatic colorectal cancer. However, there are limited and comparative data regarding the EGFR GCN in primary colorectal cancer tumors and corresponding metastases or the effect of anti-EGFR antibody treatment on EGFR GCN in recurrent disease. In addition, little is known about the potential EGFR GCN changes during anti-EGFR therapy in comparison with other treatment regimens. EGFR GCN was analyzed by EGFR immunohistochemistry-guided silver in situ hybridization in primary and corresponding recurrent local or metastatic tumors from 80 colorectal cancer patients. GCN levels were compared between KRAS wild-type patients having received anti-EGFR therapy and patients having received other forms of treatment after primary surgery. The EGFR GCN decrease between primary and recurrent tumors was more pronounced among the anti–EGFR-treated patients than among patients not treated with anti-EGFR therapy (P = .047). None of the patients experiencing an EGFR GCN increase of at least 1.0 between the primary and recurrent tumors were treated with anti-EGFR antibodies. When including only patients with distant metastases, an EGFR GCN decrease of at least 1.0 was more common among the anti–EGFR-treated patients than among patients not treated with anti-EGFR therapy (P = .028). Our results suggest that anti-EGFR antibody treatment is associated with EGFR GCN decrease between the primary and recurrent colorectal adenocarcinomas, whereas no GCN change is observed among patients receiving other forms of treatment after primary surgery.</p

EGFR gene copy number decreases during anti-EGFR antibody therapy in colorectal cancer

Epidermal growth factor receptor (EGFR) gene copy number (GCN) increase is associated with a favorable anti-EGFR antibody treatment response in RAS wild-type metastatic colorectal cancer. However, there are limited and comparative data regarding the EGFR GCN in primary colorectal cancer tumors and corresponding metastases or the effect of anti-EGFR antibody treatment on EGFR GCN in recurrent disease. In addition, little is known about the potential EGFR GCN changes during anti-EGFR therapy in comparison with other treatment regimens. EGFR GCN was analyzed by EGFR immunohistochemistry-guided silver in situ hybridization in primary and corresponding recurrent local or metastatic tumors from 80 colorectal cancer patients. GCN levels were compared between KRAS wild-type patients having received antiEGFR therapy and patients having received other forms of treatment after primary surgery. The EGFR GCN decrease between primary and recurrent tumors was more pronounced among the anti EGFR-treated patients than among patients not treated with anti-EGFR therapy (P=.047). None of the patients experiencing an EGFR GCN increase of at least 1.0 between the primary and recurrent tumors were treated with antiEGFR antibodies. When including only patients with distant metastases, an EGFR GCN decrease of at least 1.0 was more common among the anti EGFR-treated patients than among patients not treated with anti-EGFR therapy (P=.028). Our results suggest that anti-EGFR antibody treatment is associated with EGFR GCN decrease between the primary and recurrent colorectal adenocarcinomas, whereas no GCN change is observed among patients receiving other forms of treatment after primary surgery. (C) 2018 The Authors. Published by Elsevier Inc.Peer reviewe

Protein phosphatase methylesterase-1 (PME-1) expression predicts a favorable clinical outcome in colorectal cancer

Colorectal cancer (CRC) accounts for high mortality. So far, there is lack of markers capable of predicting which patients are at risk of aggressive course of the disease. Protein phosphatase-2A (PP2A) inhibitor proteins have recently gained interest as markers of more aggressive disease in certain cancers. Here, we report the role of PP2A inhibitor PME-1 in CRC. PME-1 expression was assessed from a rectal cancer patient cohort by immunohistochemistry, and correlations were performed for various clinicopathological variables and patient survival. Rectal cancer patients with higher cytoplasmic PME-1 protein expression (above median) had less recurrences (P = 0.003, n = 195) and better disease-free survival (DFS) than the patients with low cytoplasmic PME-1 protein expression (below median). Analysis of PPME-1 mRNA expression from TCGA dataset of colon and rectal adenocarcinoma (COADREAD) patient cohort confirmed high PPME1 expression as an independent protective factor predicting favorable overall survival (OS) (P = 0.005, n = 396) compared to patients with low PPME1 expression. CRC cell lines were used to study the effect of PME-1 knockdown by siRNA on cell survival. Contrary to other cancer types, PME-1 inhibition in CRC cell lines did not reduce the viability of cells or the expression of active phosphorylated AKT and ERK proteins. In conclusion, PME-1 expression predicts for a favorable outcome of CRC patients. The unexpected role of PME-1 in CRC in contrast with the oncogenic role of PP2A inhibitor proteins in other malignancies warrants further studies of cancer-specific function for each of these proteins

Progression-free survival and overall survival of anti-EGFR treated patients according to EGFR gene copy number.

<p>The hazard ratios and confidence intervals of the original discovery, validation, and combined chemorefractory patient cohorts are shown. A high <i>EGFR</i> GCN (IHC guided SISH) is associated with an improved disease outcome in all three <i>KRAS</i> wild type metastatic colorectal cancer patient cohorts treated with anti-EGFR therapy (two independent cohorts and one combined cohort of chemorefractory patients).</p

EGFR immunohistochemistry and <i>EGFR</i> silver in situ hybridization analysis in colorectal cancer.

<p>EGFR IHC shows heterogeneous staining with intensive membranous reactivity in the middle (<b>a)</b>. <i>EGFR</i> SISH from the intensively stained area showing gene clusters (<b>b</b>). <i>EGFR</i> SISH from the surrounding areas with weak or negative EGFR IHC staining shows marginally elevated or normal gene copy numbers (<b>c–d</b>).</p

Anti-EGFR response of colorectal cancer lines with different <i>EGFR</i> GCN and <i>KRAS</i> status.

<p>(<b>a</b>) <i>EGFR</i> GCN SISH analysis of the different cell lines. (<b>b</b>) A western blot image showing the levels of EGFR protein in the different cell lines. α-tubulin was used as a control for equal loading. The cell viability of the different cell lines at varying concentrations of (<b>c</b>) cetuximab and (<b>d</b>) panitumumab. The results are given as percentage of viable cells in comparison to the non-treated cells (mean ± SE of five experiments). <b>(e)</b> Western blots showing EGFR pathway signaling molecules in the different cell lines. The cells were pretreated with the indicated amounts of cetuximab for 24 hours in medium containing 1% FBS and given egf (25 µg/ml) for 5 minutes before lysis. The indicated signaling molecules were analyzed with western blotting. GAPDH was used as a control for equal loading.</p