Correlation of MYC Gene and Protein Status With Breast Cancer Subtypes and Outcome of Patients Treated With Anthracycline-Based Adjuvant Chemotherapy. Pooled Analysis of 2 Hellenic Cooperative Group Phase III Trials

Potential predictive value of circulating tumor DNA (ctDNA) mutations for the efficacy of immune checkpoint inhibitors in advanced triple-negative breast cancer

Background: In recent years, tumor immunotherapy has become a viable treatment option for triple negative breast cancer (TNBC). Among these, immune checkpoint inhibitors (ICIs) have demonstrated good efficacy in advanced TNBC patients with programmed death-ligand 1 (PD-L1) positive expression. However, only 63% of PD-L1-positive individuals showed any benefit from ICIs. Therefore, finding new predictive biomarkers will aid in identifying patients who are likely to benefit from ICIs. In this study, we used liquid biopsies and next-generation sequencing (NGS) to dynamically detect changes in circulating tumor DNA (ctDNA) in the blood of patients with advanced TNBC treated with ICIs and focused on its potential predictive value.

Methods: From May 2018 to October 2020, patients with advanced TNBC treated with ICIs at Shandong Cancer Hospital were included prospectively. Patient blood samples were obtained at the pretreatment baseline, first response evaluation, and disease progression timepoints. Furthermore, 457 cancer-related genes were evaluated by NGS, and patients’ ctDNA mutations, gene mutation rates, and other indicators were determined and coupled with clinical data for statistical analysis.

Results: A total of 11 TNBC patients were included in this study. The overall objective response rate (ORR) was 27.3%, with a 6.1-month median progression-free survival (PFS) (95% confidence interval: 3.877–8.323 months). Of the 11 baseline blood samples, 48 mutations were found, with the most common mutation types being frame shift indels, synonymous single-nucleotide variations (SNVs), frame indel missenses, splicing, and stop gains. Additionally, univariate Cox regression analysis revealed that advanced TNBC patients with one of 12 mutant genes (CYP2D6 deletion and GNAS, BCL2L1, H3F3C, LAG3, FGF23, CCND2, SESN1, SNHG16, MYC, HLA-E, and MCL1 gain) had a shorter PFS with ICI treatment (p < 0.05). To some extent, dynamic changes of ctDNA might indicate the efficacy of ICIs.

Conclusion: Our data indicate that ICI efficacy in patients with advanced TNBC may be predicted by 12 mutant ctDNA genes. Additionally, dynamic alterations in peripheral blood ctDNA might be used to track the effectiveness of ICI therapy in those with advanced TNBC.

Serum LAPTM4B as a Potential Diagnostic and Prognostic Biomarker for Breast Cancer

Background

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is an integral membrane protein overexpressed in various cancers and may function as a prognostic tumor marker. The present study is aimed at understanding the clinical significance of serum LAPTM4B in breast cancer (BC).

Methods

Serum LAPTM4B level was evaluated in 426 BC patients, 40 benign breast disease, and 80 healthy controls by ELISA. We used the receiver operator characteristic (ROC) curve to assess the diagnostic significance. 46 BC patients were recruited to monitor the dynamic change of serum LAPTM4B during adjuvant therapy (AT). In addition, sera from a subset of 330 patients undergoing AT, including anti-HER2 treatment, were collected to evaluate the association between LAPTM4B levels and AT efficacy. Descriptive and explorative statistical analyses were used to assess LAPTM4 B's potential as a diagnostic and prognostic marker in BC.

Results

Serum LAPTM4B level was significantly increased in BC patients than benign group and controls. It could well discriminate BC from healthy controls with diagnostic accuracy with an AUC of 0.912, a sensitivity of 85.9%, and a specificity of 83.8%. Compared with pre-AT, serum LAPTM4B concentration remarkably decreased after AT. In addition, patients in the invalid response group (PD + SD) showed higher LAPTM4B levels than the valid response group (PR + CR).

Conclusion

Our results proposed that serum LAPTM4B had a high diagnostic and prognostic impact as a circulating biomarker in BC.

MYC as a therapeutic target for the treatment of triple-negative breast cancer: preclinical investigations with the novel MYC inhibitor, MYCi975

BACKGROUND

MYC is one of the most frequently altered driver genes in triple-negative breast cancer (TNBC). The aim of this study was to evaluate targeting MYC for the treatment of TNBC.

METHODS

The anti-proliferative and apoptosis-inducing effects of the recently discovered MYC inhibitor, MYCi975 were investigated in a panel of 14 breast cancer cell lines representing the main molecular forms of breast cancer.

RESULTS

IC50 values for growth inhibition by MYCi975 varied from 2.49 to 7.73 µM. Response was inversely related to endogenous MYC levels as measured by western blotting (p = 0.047, r = - 0.5385) or ELISA (p = 0.001, r = - 0.767), i.e., response to MYCi975 decreased as endogenous MYC levels increased. MYCi975 also induced variable levels of apoptosis across the panel of cell lines, ranging from no detectable induction to 80% induction. Inhibition of proliferation and induction of apoptosis were greater in TNBC than in non-TNBC cell lines (p = 0.041 and p = 0.001, respectively). Finally, combined treatment with MYCi975 and either paclitaxel or doxorubicin resulted in enhanced cell growth inhibition.

DISCUSSION

Our findings open the possibility of targeting MYC for the treatment of TNBC. Based on our results, we suggest that trials use a combination of MYCi975 and either docetaxel or doxorubicin and include MYC as a putative therapy predictive biomarker.

Quantitative hormone receptor (HR) expression and gene expression analysis in HR+ inflammatory breast cancer (IBC) vs non-IBC

Background

The purpose of this study was to determine the prognostic role of hormone receptor (HR) on inflammatory breast cancer (IBC) to elucidate its aggressive biological behavior.

Methods

We evaluated the expression of estrogen receptor (ER) and progesterone receptor (PR) by immunohistochemical staining and determined the predictive and prognostic role of HR expression on 189 patients with HR+/HER2– IBC and 677 patients with HR+/HER2– stage III non-IBC. Furthermore, we performed gene expression (GE) analyses on 137 patients with HR+/HER2– IBC and 252 patients with HR+/HER2– non-IBC to detect genes that are specifically overexpressed in IBC.

Results

The expression of ER% was significantly associated with longer distant disease-free survival and overall survival. However, there was no significant relationship between ER% and neoadjuvant chemotherapy outcome. In the GE study, 84 genes were identified as significantly distinguishing HR+ IBC from non-IBC. Among the top 15 canonical pathways expressed in IBC, the ERK/MAPK, PDGF, insulin receptor, and IL-7 signaling pathways were associated with the ER signaling pathway. Upregulation of the MYC gene was observed in three of these four pathways. Furthermore, HR+/HER2– IBC had significantly higher MYC amplification, and the genetic alteration was associated with poor survival outcome.

Conclusions

Higher ER expression was significantly associated with improved survival in both HR+/HER2– IBC and HR+/HER2– stage III non-IBC patients. HR+/HER2– IBC had several activated pathways with MYC upregulation, and the genetic alteration was associated with poor survival outcome. The results indicate that MYC may be a key gene for understanding the biology of HR+/HER2– IBC.

MYC gene associated polymorphisms and Wilms tumor risk in Chinese children: a four-center case-control study

BACKGROUND

Wilms tumor (WT) is a common embryonal malignancy in the kidney, ranking fourth in childhood cancer worldwide. MYC, a critical proto-oncogene, plays an important role in tumorigenesis. Single nucleotide polymorphisms in the MYC gene may lead to the deregulation of MYC proto-oncogene protein and thereby promote the initiation and development of tumors.

METHODS

Here, we assessed the association between MYC gene associated polymorphisms and WT susceptibility by performing a case-control study with 355 cases and 1070 controls. Two MYC gene associated polymorphisms (rs4645943 C > T, rs2070583 A > G) were genotyped by TaqMan technique. Odds ratios (ORs) and 95% confidence intervals (CIs) were used for evaluating the association between these two polymorphisms and WT susceptibility.

RESULTS

No significant association was detected between the selected polymorphisms and WT risk in the overall analysis as well as stratification analysis.

CONCLUSIONS

These results indicate that neither of two selected MYC gene associated polymorphisms might affect WT susceptibility in the Chinese population. Large well-designed studies with diverse ethnicities are warranted to verify these results.

A Functional 5'-UTR Polymorphism of MYC Contributes to Nasopharyngeal Carcinoma Susceptibility and Chemoradiotherapy Induced Toxicities

MYC is a transcription factor acting as a pivotal regulator of genes involved in cell cycle progression, apoptosis, differentiation and metabolism. In this study, we evaluated the association of MYC polymorphisms with nasopharyngeal carcinoma (NPC) risk and chemoradiotherapy induced toxicities among Chinese population. By using bioinformatic tools, five potential functional single nucleotide polymorphisms of MYC were genotyped in a case-control study with 684 NPC patients and 823 healthy controls. We found two SNPs rs4645948 (C>T) and rs2071346 (G>T) were significantly associated with increased risk of developing NPC (TT+CT vs CC, OR=1.557, P=3.34×10^-4; TT+GT vs GG, OR=1.361, P=0.007, respectively). In addition, rs4645948 (C>T) was conferred with increased risk of anemia (CT vs CC, OR=2.152, P=0.001) and severe leukopenia (CT vs CC, OR=1.893, P=0.034) for NPC patients receiving chemoradiotherapy. We also found rs2071346 (G>T) variant genotype carriers were subjected to higher risk of anemia (GT vs GG, OR=1.665, P=0.022) and thrombocytopenia (GT vs GG, OR=1.685, P=0.035). Our results demonstrated that the relative expression of MYC was dramatically higher in NPC tissues compared to rhinitis tissues. Over-expression of MYC was positively correlated with advanced T stage, N stage, and late clinical stage. Notably, the expression of MYC in rs4645948 CT and TT genotypes carriers were significantly higher than CC genotype carriers. Luciferase reporter assay indicated that the T allele of rs4645948 led to significantly higher transcription activity of MYC compared to the C allele. These findings suggested that individual carrying the rs4645948 T allele may be at greater risk for NPC due to an increase of MYC transcriptional activity and an augment of MYC expression.

LAPTM4B gene copy number gain is associated with inferior response to anthracycline-based chemotherapy in hormone receptor negative breast carcinomas

PURPOSE

To determine the associations between lysosomal-associated transmembrane protein 4b (LAPTM4B) gene copy number and response to different chemotherapy regimens in hormone receptor negative (HR-) primary breast carcinomas.

PATIENTS AND METHODS

Two cohorts were analyzed: (1) 69 core biopsies from HR-breast carcinomas treated with neoadjuvant chemotherapy (anthracycline based in 72.5% of patients and non-anthracycline based in 27.5% of patients). (2) Tissue microarray (TMA) of 74 HR-breast carcinomas treated with adjuvant therapy (77.0% of the patients received anthracycline, 17.6% of the patients non-anthracycline-based therapy, and in 5.4% of the cases, no treatment data are available). Interphase FISH technique was applied on pretreatment core biopsies (cohort I) and on TMAs (cohort II) using custom-made dual-labelled FISH probes (LAPTM4B/CEN8q FISH probe Abnova Corp.).

RESULTS

In the neoadjuvant cohort in the anthracycline-treated group, we observed a significant difference (p = 0.029) of average LAPTM4B copy number between the non-responder and pathological complete responder groups (4.1 ± 1.1 vs. 2.6 ± 0.1). In the adjuvant setting, the anthracycline-treated group of metastatic breast carcinomas was characterized by higher LAPTM4B copy number comparing to the non-metastatic ones (p = 0.046). In contrast, in the non-anthracycline-treated group of patients, we did not find any LAPTM4B gene copy number differences between responder vs. non-responder groups or between metastatic vs. non-metastatic groups.

CONCLUSION

Our results confirm the possible role of the LAPTM4B gene in anthracycline resistance in HR- breast cancer. Analyzing LAPTM4B copy number pattern may support future treatment decision.