KIFC1 Is Associated with Basal Type, Cisplatin Resistance, PD-L1 Expression and Poor Prognosis in Bladder Cancer

Kinesin family member C1 (KIFC1), a minus end-directed motor protein, is reported to play an essential role in cancer. This study aimed to analyze KIFC1 expression and examine KIFC1 involvement in cisplatin resistance in bladder cancer (BC). Immunohistochemistry showed that 37 of 78 (47.4%) BC cases were positive for KIFC1. KIFC1-positive cases were associated with high T stage and lymph node metastasis. Kaplan-Meier analysis showed that KIFC1-positive cases were associated with poor prognosis, consistent with the results from public databases. Molecular classification in several public databases indicated that KIFC1 expression was increased in basal type BC. Immunohistochemistry showed that KIFC1-positive cases were associated with basal markers 34βE12, CK5 and CD44. KIFC1 expression was increased in altered TP53 compared to that in wild-type TP53. Immunohistochemistry showed that KIFC1-positive cases were associated with p53-positive cases. P53 knockout by CRISPR-Cas9 induced KIFC1 expression in BC cell lines. Knockdown of KIFC1 by siRNA increased the sensitivity to cisplatin in BC cells. Kaplan-Meier analysis indicated that prognosis was poor among KIFC1-positive BC patients treated with cisplatin-based chemotherapy. Immunohistochemistry showed that KIFC1-positive cases were associated with PD-L1-positive cases. High KIFC1 expression was associated with a favorable prognosis in patients treated with atezolizumab from the IMvigor 210 study. These results suggest that KIFC1 might be a promising biomarker and therapeutic target in BC.

Molecular profiles of genomically high risk ER+ HER2- breast cancer tumors classified as functionally basal or luminal B by the 80-gene signature.

563 Background: The 80-gene signature (BluePrint/BP) classifies early-stage breast cancers based on functional molecular pathways as luminal, HER2, or Basal-type. In the NBRST study, 13% of immunochemistry (IHC) defined ER+ HER2- cancers reclassified as Basal-type by the BP assay (ER+ Basal), and these had worse prognosis but responded better to neoadjuvant chemotherapy than ER+ HER2- cancers classified as genomically luminal-type. The 70-gene risk of recurrence signature (MammaPrint/MP) further stratifies luminal-type cancers into low risk luminal A or high risk (HR) luminal B. HR cancers can be further stratified into High 1 (H1) or High 2 (H2), and the I-SPY2 trial has shown higher pCR rates in ER+ cancers classified as H2. Here, we investigated biological differences among ER+ Basal, ER- Basal, H1 luminal B, and H2 luminal B cancers by full transcriptome analysis. Methods: From the FLEX Study (NCT03053193), 1501 breast cancers with known IHC ER status were classified by MP and BP: 103 ER+ Basal, 210 ER- Basal and 1188 luminal B (H1 n=1034, H2 n=154). Clinical factors were assessed by either the Chi-square or Fisher’s exact tests; ANOVA or t test were used to analyze age. Differentially expressed genes (DEGs) were detected using Limma and pathway analyses were performed with GSEA. DEGs with a fold change >2 and FDR < 0.05 were considered significant. Results: Basal-type cancers (ER+/ER-) were larger and higher grade than luminal B cancers. Clustering analysis showed similar transcriptional profiles between ER+ Basal and ER- Basal cancers, distinct from luminal B cancers. Few DEGs were detected between ER+ Basal and ER- Basal cancers, and significantly more DEGs were found between ER+ Basal and luminal B cancers. Only three upregulated genes were detected in ER+ Basal compared to ER- Basal cancers: ESR1 and two immune-related genes ( FDCSP and LTF). Enrichment analysis of DEGs indicated increased immune activation and cell proliferation in ER+ Basal and ER- Basal cancers, and decreased estrogen response between ER+ Basal and luminal B cancers. Enrichment analysis between luminal B H1 and H2 cancers showed H2 cancers had higher immune activation and cell proliferation and lower estrogen response. Conclusions: Reclassification by BP of IHC defined ER+ HER2- cancers identified a subgroup of ER+ cancers that are biologically closer to ER- Basal than luminal-type cancers. Significant differences in response to neoadjuvant chemotherapy that have been seen between ER+ Basal and luminal B breast cancers lend support to the clinical importance of these findings. These data explain the poor prognosis observed in patients with ER+ Basal cancers and suggest that optimized chemotherapy, such as that for triple negative cancer, might be of benefit. BP provides clinically actionable information beyond pathological subtyping, which may guide neoadjuvant treatment recommendations. Clinical trial information: NCT03053193.

Whole transcriptome analysis comparing HR+ HER2- breast cancer tumors from patients 50 years.

565 Background: Recent prospective clinical trials have demonstrated a differential chemotherapy effect based on age (≤ 50 vs. > 50 years) or menopausal status (pre- vs. post-) in a genomic low risk group. Whether this is a direct anti-tumor effect of chemotherapy or a secondary ovarian function suppression effect caused by chemotherapy is unclear. We aimed to compare the biological characteristics of breast cancer tumors from patients aged ≤ 50 years and from patients aged > 50 years using whole transcriptome analysis to provide insights into this differential chemotherapy response. Methods: The FLEX Registry (NCT03053193) enrolls stage I-III breast cancer patients who receive 70-gene signature (MammaPrint/MP) test with or without 80-gene signature (BluePrint/BP) test and consent to clinically annotated transcriptome data collection. 3868 patients with HR+HER2- tumors were evaluated, of whom 808 were aged ≤ 50 years and 3060 were aged > 50 years. Clinical risk was assessed based on the MINDACT algorithm. MP classified tumors as low risk (LR) or high risk (HR). HR was stratified to H1 or H2; H2 exhibits a greater chemotherapy response. BP and MP classified tumors as luminal A-, luminal B-, HER2-, or basal-type. Differences in MP, BP, and clinical features were assessed by chi-squared or t test. For gene expression analysis, older patients were randomly selected to obtain an equal sample size as younger patients. Differentially expressed genes (DEGs) were detected using limma and considered significant with FDR <0.05 and fold change ≥ 2. Results: Approximately 70% of patients aged ≤ 50 were pre or peri-menopausal, whereas 90% of patients aged > 50 were post-menopausal. A higher proportion of patients aged ≤ 50 had tumors of high clinical risk (54%) compared to patients aged > 50 (39%) (p < 0.001). Approximately 53% of patients aged ≤ 50 had a HR tumor, of whom 25% classified as H2, while patients aged > 50 had a lower frequency (44%) of HR tumors (p<0.001). Additionally, younger patients had more tumors that classified as BP Luminal B and Basal-type than older patients (p<0.001). Principal component analysis of the top 500 genes with the highest variance revealed no distinct clustering by age group. Accordingly, only 5 DEGs were detected in tumors from patients aged ≤ 50 compared to patients aged > 50, and even fewer DEGs were detected when adjusting for MP risk and BP subtype group. Conclusions: Whole transcriptome analysis identified no substantial differences in gene expression between tumors, including Low Risk Luminal-type tumors, from women aged ≤ 50 (mostly pre or peri-menopausal) and women aged > 50 (mostly post-menopausal). These data support the likely explanation that the observed age-dependent difference in chemotherapy benefit in women ≤ 50 or >50 years of age is not due to intrinsic biological differences in breast cancers due to age, but rather to differences in the effect of chemotherapy on the host. Clinical trial information: NCT03053193.

The ECM Modulator ITIH5 Affects Cell Adhesion, Motility and Chemotherapeutic Response of Basal/Squamous-Like (BASQ) Bladder Cancer Cells

This study aims at characterizing the role of the putative tumor suppressor ITIH5 in basal-type bladder cancers (BLCA). By sub-classifying TCGA BLCA data, we revealed predominant loss of ITIH5 expression in the basal/squamous-like (BASQ) subtype. ITIH5 expression inversely correlated with basal-type makers such as KRT6A and CD44. Interestingly, Kaplan–Meier analyses showed longer recurrence-free survival in combination with strong CD44 expression, which is thought to mediate ITIH-hyaluronan (HA) binding functions. In vitro, stable ITIH5 overexpression in two basal-type BLCA cell lines showing differential CD44 expression levels, i.e., with (SCaBER) and without squamous features (HT1376), demonstrated clear inhibition of cell and colony growth of BASQ-type SCaBER cells. ITIH5 further enhanced HA-associated cell-matrix attachment, indicated by altered size and number of focal adhesion sites resulting in reduced cell migration capacities. Transcriptomic analyses revealed enrichment of pathways and processes involved in ECM organization, differentiation and cell signaling. Finally, we provide evidence that ITIH5 increase sensitivity of SCaBER cells to chemotherapeutical agents (cisplatin and gemcitabine), whereas responsiveness of HT1376 cells was not affected by ITIH5 expression. Thus, we gain further insights into the putative role of ITIH5 as tumor suppressor highlighting an impact on drug response potentially via the HA-CD44 axis in BASQ-type BLCA.

Differential expression of spermatogenesis associated serine rich 2 in cancers of the breast.

Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding spermatogenesis associated serine rich 2, SPATS2, when comparing primary tumors of the breast to the tissue of origin, the normal breast. SPATS2 mRNA was present at significantly higher quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of SPATS2 in primary tumors of the breast was correlated with distant metastasis-free survival in patients with basal type cancer. SPATS2 may be of relevance to initiation, maintenance or progression of cancers of the female breast.

Differential expression of UNC5B in cancers of the breast.

Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding unc-5 netrin receptor B, UNC5B, when comparing primary tumors of the breast to the tissue of origin, the normal breast. UNC5B mRNA was present at significantly higher quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of UNC5B in primary tumors of the breast was correlated with overall survival in patients with basal type cancer. UNC5B may be of relevance to initiation, maintenance or progression of cancers of the female breast.