The prognostic role of serum C-X-C chemokine receptor type 4 in patients with metastatic or recurrent colorectal cancer

Engineering non-antibody human proteins as efficient scaffolds for selective, receptor-targeted drug delivery

Self-assembling non-immunoglobulin scaffold proteins are a promising class of nanoscale carriers for drug delivery and interesting alternatives to antibody-based carriers that are not sufficiently efficient in systemic administration. To exploit their potentialities in clinics, protein scaffolds need to be further tailored to confer appropriate targeting and to overcome their potential immunogenicity, short half-life in plasma and proteolytic degradation. We have here engineered three human scaffold proteins as drug carrier nanoparticles to target the cytokine receptor CXCR4, a tumoral cell surface marker of high clinical relevance. The capability of these scaffolds for the selective delivery of Monomethyl auristatin E has been comparatively evaluated in a disseminated mouse model of human, CXCR4⁺ acute myeloid leukemia. Monomethyl auristatin E is an ultra-potent anti-mitotic drug used against a range of hematological neoplasias, which because of its high toxicity is not currently administered as a free drug but as payload in antibody-drug conjugates. The protein nanoconjugates generated here offer a collective strength of simple manufacturing process, high proteolytic and structural stability and multivalent ligand receptor interactions that result in a highly efficient and selective delivery of the payload drug and in a potent anticancer effect. The approach shown here stresses this class of human scaffold proteins as promising alternatives to antibodies for targeted drug delivery in the rapidly evolving drug development landscape.

Different Toxicity Profiles Predict Third Line Treatment Efficacy in Metastatic Colorectal Cancer Patients

The nucleoside trifluridine/tipiracil (TAS-102) and the multikinase inhibitor regorafenib significantly improved survival in metastatic colorectal cancer patients (mCRC). Both treatments are characterized by different treatment-related adverse events but detailed analyses of predictive side effects are rare. In this retrospective, observational, real-life study, clinical data on mCRC patients treated with trifluridine/tipiracil or regorafenib at the Medical University of Vienna, Austria and the University Hospital Zurich, Switzerland were collected. The correlation between adverse events and response or survival rates were calculated performing Fisher’s exact test and log-rank test, respectively. Common adverse events of any grade included fatigue (52%), nausea/vertigo (34%), anemia (26%), and leukopenia (22%) in trifluridine/tipiracil patients and fatigue (42%), hand-foot-skin syndrome (36%) and hoarseness (34%) in patients upon regorafenib treatment. In trifluridine/tipiracil patients the prevalence of leukopenia (p = 0.044) and weight loss (p = 0.044) was prognostic, whereas leukopenia (p = 0.044) and neutropenia (p = 0.043) predicted PFS. The disease control rate was not significantly affected. In regorafenib-treated patients, the prevalence of nausea (p = 0.001) was prognostic, while oral mucositis predicted PFS (p = 0.032) as well as the DCR (p = 0.039). In conclusion, we underline the efficacy of trifluridine/tipiracil and regorafenib in the real-life setting. We describe predictive adverse events like neutropenia/leukopenia, which might be used as surrogate marker in anticancer therapy beyond second line treatment.

A chemokine/chemokine receptor signature potentially predicts clinical outcome in colorectal cancer patients

BACKGROUND

Differential expression of chemokines/chemokine receptors in colorectal cancer (CRC) may enable molecular characterization of patients' tumors for predicting clinical outcome.

OBJECTIVE

To evaluate the prognostic ability of these molecules in a CRC cohort and the CRC TCGA-dataset.

METHODS

Chemokine (CXCL-12α, CXCL-12β, IL-17A, CXCL-8, GM-CSF) and chemokine receptor (CXCR-4, CXCR-7) transcripts were analyzed by RT-qPCR in 76 CRC specimens (normal: 27, tumor: 49; clinical cohort). RNA-Seq data was analyzed from the TCGA-dataset (n= 375). Transcript levels were correlated with outcome; analyses: univariate, multivariable, Kaplan-Meier.

RESULTS

In the clinical cohort, chemokine/chemokine receptor levels were elevated 3-10-fold in CRC specimens (P⩽ 0.004) and were higher in patients who developed metastasis (P= 0.03 - < 0.0001). CXCR-4, CXCR-7, CXCL-12α, CXCL-8, IL-17 and GM-CSF levels predicted metastasis (P⩽ 0.0421) and/or overall survival (OS; P⩽ 0.0373). The CXCR-4+CXCR-7+CXCL-12 marker (CXCR-4/7+CXCL-12 (α/b) signature) stratified patients into risk for metastasis (P= 0.0014; OR, 2.72) and OS (P= 0.0442; OR, 2.7); sensitivity: 86.67%, specificity: 97.06%. In the TCGA-dataset, the CXCR-4/7+CXCL-12 signature predicted metastasis (P= 0.011; OR, 2.72) and OS (P= 0.0006; OR: 4.04). In both datasets, the signature was an independent predictor of clinical outcome.

CONCLUSIONS

Results of 451 specimens from both cohorts reveal that the CXCR-4/7+CXCL-12 signature potentially predicts outcome in CRC patients and may allow earlier intervention.

Nanostructured toxins for the selective destruction of drug-resistant human CXCR4+ colorectal cancer stem cells

Current therapies fail to eradicate colorectal Cancer Stem Cells (CSCs). One of the proposed reasons for this failure is the selection, by chemotherapy exposure, of resistant cells responsible for tumor recurrence. In this regard, CXCR4 overexpression in tumor associates with resistance and poor prognosis in colorectal cancer (CRC) patients. In this study, the effectiveness of engineered CXCR4-targeted self-assembling toxin nanoparticles has been explored in the selective killing of CXCR4⁺ human colon-CSCs compared to 5-Fluorouracil and Oxaliplatin, both classical CRC chemotherapeutic agents. To assess this, 3D spheroid colon-CSCs cultures directly derived from CRC patients and CRC-CSC spheroid-derived tumor mouse models were developed. In these animal models, nanostructured toxins show highly selective induction of pyroptosis in the absence of apoptosis, thus having a great potential to overcome tumor resistance, since the same tumor models show resistance to chemotherapeutics. Results set the basis for further development of more efficient therapies focused on selective CXCR4⁺ CSCs elimination activating non-apoptotic mechanisms and represent a pre-clinical proof of concept for the use of CSCs-targeted nanostructured toxins as protein drugs for CRC therapy.

Optimizing Treatment Sequence for Late-line Metastatic Colorectal Cancer Patients Using Trifluridine/Tipiracil and Regorafenib

BACKGROUND

Treatment sequencing for patients with refractory metastatic colorectal cancer (mCRC) has been highly debated. The thymidine-based nucleoside trifluridine/tipiracil (TAS-102) and the multikinase inhibitor regorafenib have demonstrated clinical benefits in randomized phase III trials compared with placebo. However, limited data are available on the most optimal therapy sequence involving TAS-102 and regorafenib.

PATIENTS AND METHODS

In the present retrospective, observational, real-life study, clinical data on mCRC patients treated with TAS-102 or an alternative salvage treatment at the Medical University of Vienna and University Hospital Zurich were collected from January 2013 to December 2016.

RESULTS

A total of 85 patients whose disease had progressed during fluoropyrimidine-based therapy (FBT) with or without an antibody were included. The disease control rate in patients treated with TAS-102 after FBT-based treatment was 24% compared with 35% in patients treated with regorafenib after FBT-based treatment (adjusted odds ratio, 1.75; 95% confidence interval, 0.41-7.47; P = .449). The progression-free survival (PFS) and overall survival (OS) for patients treated with TAS-102 was 2.8 months (quartile, 2.0-4.8 months) and 15.9 months, respectively. When the data were analyzed according to the subgroups of patients with or without an FBT-free period, the TAS-102-treated patients with a previous FBT-free interval had a PFS of 3.1 months and OS of 17.7 months compared with a PFS of 2.2 months and OS of 8.1 months for patients who received TAS-102 immediately after FBT.

CONCLUSION

Our results have confirmed the efficacy of TAS-102 and regorafenib in the real-life setting. The treatment sequence analysis showed a tendency for longer PFS and OS for TAS-102-treated patients after an FBT-free interval. Prospective randomized data are needed to gain more information about the most beneficial therapy sequence in the salvage treatment of mCRC.

Serum CXCL12, but not CXCR4, Is Associated with Head and Neck Squamous Cell Carcinomas

Background: Squamous cell carcinoma (SCC) is the most frequent malignancy of the head and neck (HN) region. We here evaluated associations of stromal cell derived factor-1 (SDF-1or CXCL12) and its receptor, CXCR4, with HNSCCs. Materials and Methods: Sixty newly diagnosed HNSCC patients were enrolled in the patient group, and 28 healthy individuals in the control group. Plasma levels of CXCL12 and CXCR4 were measured using ELISA kits. Results: There was a significant difference in mean CXCL12, but not CXCR4, plasma levels between the patient and control groups (P=0.0001). No significant associations were found between mean plasma levels of either CXCL12 or CXCR4 with age, gender, tumor site, tumor size, lymph-node involvement or tumor stage. Conclusion: For the first time, our findings demonstrate a significant association between serum CXCL12 but not CXCR4 levels and HNSCCs.